City of Lewiston, Maine Notice to Contractors

Transcription

1 City of Lewiston, Maine Notice to Contractors Bid Date: 02/27/14 Bid No Proposal: Sealed proposals for Technical Assistance Environmental Monitoring & Sample Analysis which includes furnishing all labor, equipment and materials required to satisfactorily collect and analyze ground and surface water samples, as well as prepare correspondence and reports, in accordance with the City of Lewiston s (City) approved Environmental Monitoring Program (EMP) and all other incidental work as necessary to satisfactorily complete the project as outlined in the Supplemental and Standard Specifications. All proposals will be received by the City of Lewiston, Maine, at the office of the Director of Budget/Purchasing until 2:00 p.m., Thursday February 27, 2014 and then at said office publicly opened and read aloud. Only sealed bids will be accepted. Faxed bids will not be considered. Each bidder is required to state in his/her Proposal his/her name and place of residence and the names of all persons or parties interested as principals with him/her; and that the proposal is made without any connection with any other bidder making any Proposal for the same work; and that no person acting for, or employed by, the City of Lewiston is directly or indirectly interested in the Proposal or in any contract which may be entered into to which the Proposal relates, or in any portion of the profits therefrom, except as provided by the City. The proposal must be signed by the bidder with his/her full name and address and be enclosed in a sealed envelope together with the bid security. The sealed envelope shall be marked with the name and address of the bidder and entitled: Technical Assistance Environmental Monitoring & Sample Analysis and addressed to: Director Budget/Purchasing, City Hall, 27 Pine St., Lewiston, Maine Any bidder may withdraw his/her Proposal prior to the scheduled time for the opening of Proposals upon presentation to the Director Budget/Purchasing of a request, in writing, to do so. Any bidder who withdraws his/her Proposal within thirty (30) days after the actual opening thereof shall be considered to have abandoned his/her Proposal and the bid security accompanying the Proposal will be forfeited to the City of Lewiston. Any Proposal received after the scheduled opening time shall not be considered. The Finance Committee reserves the right to waive any formality and may consider as informal any Proposal not prepared in accordance with these provisions. The Finance Committee reserves the right to accept any Proposal or reject any or all Proposals if it is deemed to be in the public interest to do so. 1

2 No Proposal will be considered unless it is accompanied by a bid security in the form of a bond or certified check in the amount of ten percent (10%) of the total bid price, made out in favor of the City of Lewiston. All bid securities will be released upon deliverance of a signed Contract or, if no Contract award is made, within forty-five (45) days after the opening of the Proposals, unless forfeited as herein stipulated. The Contract must be signed within ten (10) days, Saturdays, Sundays, and holidays excepted, after the date of notification to the bidder by the Director Budget/Purchasing of the acceptance of his/her Proposal and readiness of the Contract to be signed. If the bidder fails or neglects, after such notification, to execute the Contract, the Finance Committee may determine that the Proposal has been abandoned; and, in such case, the bid security accompanying the Proposal shall be forfeited to the City of Lewiston. The work is to be commenced within ten (10) days after the date of the Contract signing, weather permitting, unless otherwise specified in the Supplemental Specifications or directed by the Director Budget/Purchasing, in writing, and is to be continued with diligent regularity until its completion within the time limit specified in the bidder s Proposal. All Proposals must be made on the blank Proposal Form found in these Contract Documents, or as otherwise provided for in the Specifications. Bidders shall state prices for each separate item of work as called for in the Proposal Form. These prices are to cover all the expenses incidental to the completion of the work in full conformity with the Contract Documents. The prices proposed by the bidder must be typed or printed (in ink) and legible, in order to avoid ambiguity. Forms, which are not typed, or legible, or are ambiguous may be considered irregular and subject to rejection. Each bidder shall make his/her own examinations and estimates, and shall not hold the City, its agents or employees responsible for, or bound by, any schedule, estimate, sounding, boring, or any plan thereof; and shall, if any error in any plan, drawing specifications or direction relating to anything to be done under this Contract comes to his/her knowledge, report it at once, in writing, to the Superintendent Solid Waste. The Contractor shall supply all equipment, materials and labor required to complete the work unless otherwise provided for in the Supplemental Specifications. The cost and expense of all the necessary labor, tools and equipment required to complete the work shall be included in the prices stated in the Proposal. Specifications may be obtained at the office of the Director Budget/Purchasing, City Hall, Lewiston, Maine. All questions by prospective bidders pertaining to the Contract Documents and Specifications must be received, in writing, by the City, at least five (5) days before the date set for the opening of the Proposals. Any questions which, in the opinion of Lewiston s Director Budget/Purchasing, require interpretation, will be sent by mail, with the interpretation, in the form of a numbered Addendum, to each person or firm who has taken out a set of Contract 2

3 Documents, not later than three (3) days prior to the scheduled opening of the Proposals. Addenda issued later than three (3) days prior to the scheduled opening of the Proposals may be transmitted via facsimile. Bidders shall acknowledge receipt of all Addenda in the space provided therefore in the Proposal form, whether the Addenda are in response to questions or otherwise issued by the City and whether the Addenda are received by mail or facsimile. The Supplemental Specifications delineate the particular project to which the Contract Documents pertain. Should any discrepancy be found to exist between the Supplemental Specifications and the Standard Specifications, the Supplemental Specifications shall govern. If the Bid Price of any of the bid items submitted with this Proposal appear to be extremely low or high, compared to the actual cost of performing the work, the Bidder may be asked to explain, in writing, how the work in question is to be performed at the price or prices bid before a decision is made by the City to award a Contract or reject the Bid. Proposals will be considered irregular and will be subject to rejection for the following reasons: 1) If the Proposal is on a form other than that furnished by the City or if the form is altered in any way. 2) If there are unauthorized additions, conditional or alternate bids or irregularities of any kind which may make the Proposal incomplete, indefinite or ambiguous as to its meaning. 3) If the bidder adds any provisions reserving the right to accept or reject an award or to enter into a Contract pursuant to an award. 4) If the Proposal does not contain a unit price for each pay item listed unless otherwise specified. 5) If any of the bid prices are unbalanced, or do not reflect the actual cost required to perform the work, as outlined in the Plans and Specifications. 3

4 City of Lewiston Proposal For Technical Assistance Environmental Monitoring & Sample Analysis To: Director Budget/Purchasing City Hall, Lewiston, Maine Dear Sir/Madam: The undersigned hereby declares that he/she has carefully examined the location of the proposed work, the proposed Contract Form and the Contract Documents therein referred to and that he/she proposes and agrees, if this Proposal is accepted, that he/she will contract with the City of Lewiston, by its City Administrator to provide all machinery, tools, labor, equipment and all other means to do all the work and to furnish all the materials, except those specified in the Supplemental Specifications to be furnished by the City, necessary to complete the work in the manner and time therein prescribed in accordance with the conditions and requirements set forth in the Contract Documents and the requirements of the Superintendent Solid Waste and/or Director of Public Works as provided for therein. The Contractor shall provide unit costs for all labor and equipment and all supplies required to complete the work described in the Supplemental Specifications. All work shall be performed on a time and materials basis with an estimated cost not to exceed provided in the following proposal. If work is completed in less time and/or under the budget estimate provided in this proposal, the City shall provide payment for the actual cost of work performed. In addition to the Proposal for completing the work described in the Supplemental Specifications, the Contractor will include a schedule of fees (hourly rate) for personnel and other basic costs, as may be required, for Technical Assistance related to the City s EMP, on an as needed basis. Written time sheets, which include labor hours, equipment hours and supplies consumed shall be provided to the Superintendent Solid Waste on a monthly basis. The City shall not provide payment in excess of the budget estimate unless prior written approval is provided by the Superintendent Solid Waste. The undersigned further agrees that, after notification by the Director Budget/Purchasing of the acceptance of his/her Proposal and the readiness of the Contract for signature, he/she will execute the Contract unless otherwise specified by the Director of Public Works or the Superintendent Solid Waste in writing; and that he/she will prosecute the work to its completion within the time limit specified in the Contractor s Proposal. The undersigned further agrees that the only persons or parties interested in this Proposal, as principals, are named below; that the Proposal is made without any connection with any other person or party making any Proposal for the same work; and that no person acting for or employed by the City of Lewiston is directly or indirectly interested in this Proposal or in 4

5 any contract which may be made under it or in profits expected to arise therefrom, except as provided by the City Charter. The full names and addresses of all the persons and parties interested in this Proposal, as principals, are as follows: (Give first and last names in full; and in the case of a Corporation, give names and addresses of President, Treasurer and Manager; and in the case of a Partnership, give names and addresses of members): Accompanying this Proposal is a bid security deposit in the amount of ($ ) which is to become the property of the City of Lewiston, by forfeiture, if the undersigned fails, after notification by the Director Budget/Purchasing of the acceptance of his/her Proposal, to execute a contract with the City and furnish the services agreed to herein, weather permitting; or, in the case the undersigned withdraws his/her Proposal within thirty (30) days, after the opening of the Proposals. Otherwise, the deposit will be returned to the undersigned in accordance with the provisions in the Notice to Contractors. Signature of person, firm, or corporation making bid: Company Name: Signature: Printed Name & Title: Mailing Address: Business location: Firm s IRS ID #: Date: Telephone#: Fax #: Address: 5

6 CONTRACT FOR TECHNICAL ASSISTANCE ENVIRONMENTAL MONITORING & SAMPLE ANALYSIS This Agreement, made and entered into this day of in the year two thousand and fourteen, between the City of Lewiston, Maine, a municipal corporation existing under the laws of the State of Maine, hereinafter called Owner, by its City Administrator, party of the first part, and Hereinafter called Contractor, with legal address and principal place of business at Party of the second part: WITNESSETH: That the parties to these presents, each in consideration of the covenant and agreements on the part of the other herein contained, have covenants and agreed and do hereby covenant and agree, the party of the first part for itself and the party of the second part for themselves and their heirs, executors, administrators and assigns under the penalties expressed as follows: That this Agreement includes the following documents, hereinafter referred to as Contract Documents, which are attached hereto and incorporated by reference into this Agreement: 1. Notice to Contractors 2. Proposal 3. Supplemental Specifications 4. Standard Specifications 5. Contract Plans, if any 6. Addenda, if any 7. Federal Conditions, if any That the party of the second part will do all the work, furnish all the materials, tools and equipment, except as otherwise specified, and do everything necessary and proper for performing and faithfully completing the work required by the Contract Documents in strict conformity with the provisions of the Contract Documents within the time specified in the Supplemental Specifications. 6

7 That the party of the first part will pay the party of the second part as full compensation for well and faithfully completing the whole work according to the Contract Documents as follows: The party of the second part represents and warrants: a) That he/she is financially solvent; and is experienced in and competent to perform the work; and is able to furnish the plant, materials supplies, labor, and equipment to be furnished by him/her; and: b) That he/she is familiar with all Federal, State, Municipal and Department laws, ordinances and regulations which may in any way affect the work or those employed therein; and: c) That such temporary and permanent services required by the Contract Documents to be done by him/her can be satisfactorily executed for the purposes for which it is intended; and that such services will not injure any person or damage any property; and: d) That he/she has carefully examined the Contract Documents and the site of the work to be performed; and from his/her own investigation has satisfied himself/herself as to the nature and location of the work, the character of the equipment and other facilities needed for the performance of the work, the general and local conditions; and all the other materials and conditions which may in any way affect the work or its performance. IN WITNESS WHEREOF, the said City, by its City Administrator and the said by its thereunto duly authorized have hereunto set their hands and seals the day and year first above written. Signed in the presence of: City of Lewiston, Maine By: Edward A. Barrett City Administrator By: Contractor 7

8 Supplemental Specifications Division SCOPE OF WORK: It is the intention of these Contract Documents to require the complete and satisfactory collection and analysis of ground and surface water samples and preparation of the annual Environmental Monitoring Report as described in the City of Lewiston s (City) Environmental Monitoring Program (EMP), approved by the Maine Department of Environmental Protection (DEP) in March 2000, and revised in July 2009, and the State of Maine s Solid Waste Management Regulations (CMR Rules) and all other reports related to the approved EMP as may be required by the City s Solid Waste and Recycling Facility (Facility), for a term of not less than five (5) years. The successful contracting firm (Contractor) shall be responsible for supplying all labor, equipment and materials necessary to complete these tasks, as described in these Contract Documents, which includes the Supplemental & Standard Specifications, unless written approval is granted by the Solid Waste Facility s Superintendent QUALIFICATIONS: The Contractor shall provide evidence they meet and maintain appropriate qualifications for preparation of the annual EMP report and all other technical assignments requested by the City in accordance with the approved EMP and DEP Solid Waste Regulations and collection and analysis of ground and surface water samples and all other technical assignments requested by the City in accordance with the Facility s approved EMP and DEP Solid Waste Regulations. In addition, the Contractor shall ensure all laboratory analysis is performed by a firm certified and in good standing with Maine s Health & Environmental Laboratory certification program and is acceptable to the City TIME LIMIT: The project will be awarded within thirty (30) days of the bid opening. The Contractor may begin work on the scope of work as soon as the Contract is executed. All work described in these Contract Documents shall be completed in accordance with DEP regulations or as required by the Solid Waste Facility s Superintendent CHANGE IN THE SCOPE OF WORK: The City of Lewiston reserves the right to add or delete portions of the work required under this Contract, using unit prices established in the Proposal. The Contractor s attention is directed to Sections 22.5 and 22.6 of the Specifications Extra Work and Reduction of Work respectively. If no unit prices exist, a change order must be negotiated between the City of Lewiston and the Contractor. 8

9 10.4 SITE INVESTIGATION: The Contractor shall examine the Plans, Specifications and site of the work and from his/her own investigation, determine the nature and location of the work, the general and local conditions, particularly those bearing on access, transportation, quality and quantity of surface and sub-surface materials to be encountered, the machinery and services required to complete the Project as required by the Contract Documents, and all other aspects of the work 10.5 FUNDING: This Project is being funded entirely by the City of Lewiston. No Federal or State funds are proposed to be used in completion of this Project SAFETY: The secure landfill located at the Facility is classified as a Subtitle D landfill, in conformance with Federal and State regulations. As such, the secure landfill contains Municipal Solid Waste (MSW), MSW incinerator ash, and other non-hazardous solid waste materials. The attenuated landfill, also located at the Facility, operated as the City s primary site for disposal of MSW, Construction & Demolition Debris, Industrial and other waste materials, for approximately 40 years, prior to its closure in The Contractor is responsible for becoming familiar with landfill operations and the environmental conditions at the site (based on information available in the Facility s Operations Manual) as well as the health and safety of their own employees. The Contractor shall conform with all work safety requirements of all pertinent regulatory agencies, and shall secure the site for the working conditions in compliance with the same. Any and all manhole and confined space entry procedures shall conform to City policy, Maine State Department of Labor Regulations, and Federal Occupational Safety and Health Administration (OSHA) regulations QUALIFICATIONS OF BIDDERS: The Contractor shall provide evidence they have a minimum of five years experience preparing technical reports and performing data analysis as described in the Facility s approved EMP (and associated tasks described in Supplemental Specifications Division 10) and collecting and analyzing surface and groundwater samples in accordance with Maine DEP Solid Waste regulations and DEP s Environmental Laboratory certification program as described in the Facility s approved EMP (and associated tasks described in Supplemental Specifications Division 10) 9

10 at special waste landfills similar to Lewiston s Solid Waste Facility or larger or similar environmental projects and shall provide a minimum of three references of similar projects as part of their Proposal. The City will determine, based on references from clients listed in the Contractors proposal, as well as references from regulatory agencies, the Contractors suitability to perform the tasks described in these Contract Documents SCOPE OF SERVICE Preparation of the Annual Environmental Monitoring Report: The Contractor shall review and validate all data generated from sample analysis within the Facility s ground and surface water monitoring network, in accordance with the approved EMP. The Contractor will also be responsible for collection and analysis of samples from the monitoring sites described in Section Scope Of Service Environmental Monitoring & Sample Analysis. The Contractor will utilize the analytical data obtained from the collection & analysis of these water samples to prepare and complete the annual EMP report and any other reports or technical assistance required by the City, during the term of this contract. In their proposal, the contractor shall provide the City with a Lump Sum budget estimate, for each year of the Contract, to complete the Scope of Service Preparation of the Annual Environmental Monitoring Report, which represents the contractor s best judgment as to the level of effort required to complete the following four tasks. In order to complete the annual report and provide all technical assistance described in these Contract Documents, the Contractor shall perform the following tasks: Task 1 Review the Facility s approved EMP, historical data and reports The City will make available, within one month after notification by the Director Budget/Purchasing of the acceptance of his/her Proposal and the Contractor shall review the Facility s EMP (approved by the Maine DEP, March 2000, revised July 2009), previous environmental monitoring reports, and other documents related to the Facility s hydrogeologic conditions as needed to understand the hydrogeology of the site. Task 2 Water Quality Data Validation and Statistical Analysis Upon receipt, the Contractor shall enter the laboratory results of sample analysis into a Microsoft Windows Excel spreadsheet (prepared by others). The Contractor will be responsible for entering all analytical data into the database, reviewing the database for typing errors and making corrections as needed. The City will provide the Contractor with a copy of the database in an electronic format (compact disc) no later than 30 days following the award of this contract. In addition, the Contractor will provide the City with either paper copies or electronic copies of all laboratory results and chain of custody forms generated as part of the sample collection and analysis. The Contractor shall review the database in accordance with the data validation procedures described in the Facility s EMP, DEP Solid Waste Management Regulations (CMR 405.3(A)) and all other Federal and State regulations, as required. 10

11 Statistical analysis of the database, provided by the City, shall be performed by the Contractor as required in the Facility s approved EMP and Maine s Solid Waste Management Regulations (CMR 405.3(B)). The statistical analysis shall include, but may not be limited to: 1) A comparison of upgradient water quality or identification of an intra-well trend. 2) Identification of statistically significant trends in parameter concentrations of the groundwater as a function of time. 3) Identification of any statistically significant differences in groundwater quality between downgradient sample locations and corresponding upgradient or background sample locations. Task 3 Preparation of the Annual Environmental Monitoring Report Annually, the Contractor shall review the ground and surface water quality data from the previous years (which includes Summer, Fall and Spring monitoring rounds) monitoring rounds and prepare a draft report for the City to review no later than April 10 (weekends and holidays excluded). The annual report shall include a comprehensive narrative summarizing the results of the previous years monitoring events. Specifically, the narrative shall discuss: data validation performed on the database; review of statistical analysis conducted on the database, including any observed trends; exceedence of any applicable water quality standards; interpretation of general water quality at the Facility; including interpretations of Facility activities on water quality at the Facility, and; appropriate conclusions and recommendations. In addition, the report shall include, but may not be limited to, all reporting requirements specified in the Facility s approved EMP and Maine s Solid Waste Management Regulations (MWMR 405.3(C)). Task 4 Review of Environmental Monitoring Results The Contractor shall review, after each tri-annual monitoring event, all ground and surface water quality monitoring results prepared in accordance with the requirements described in the Facility s EMP and all other applicable State and Federal requirements. As part of their review of the water quality data, the Contractor shall note any and all monitoring results which indicate a possible deterioration in ground or surface water quality, based on DEP regulatory guidance (CMR C.2.i and 405.3), and report said findings to the Superintendent, Solid Waste, within 14 days of the date they receive the water quality monitoring results. In the event that the statistical analysis of the water quality data, performed by the Contractor in accordance with DEP Solid Waste Management Regulations, confirms deterioration of the water quality at a monitoring site, the Contractor shall prepare and submit to the Superintendent, an evaluation of the causes of the deterioration of water quality at the monitoring point, in accordance with the DEP s Solid Waste regulations (CMR C.2.i), within 30 days of receiving the water quality monitoring data. The cost of the evaluation and any additional reports prepared for submittal to DEP, required by the Superintendent, are considered outside the Lump Sum budget estimate - Preparation of the Annual Environmental Monitoring Report - provided by the Contractor in their Proposal. Compensation for this additional work will be based on the schedule of hourly fees for general consultation as described in 10.9 Additional Technical Assistance. 11

12 SCOPE OF SERVICE Environmental Monitoring & Sample Analysis: The City is seeking assistance with collection and analysis of samples from the following ground and surface water sources: a. the domestic water supply wells located at 359 & 463 River Rd., b. the leachate collection system, c. the secure landfill s leak detection system, d. surface water sites, e. monitoring wells around the perimeter of the attenuated landfill, and f. monitoring wells around the perimeter of the secure landfill. As such, the following criteria shall be adhered to regarding collection and analysis of samples: 1) The contractor shall supply all labor, equipment, and materials necessary to collect, analyze, and report results of samples obtained from all monitoring locations described in the Facility s EMP. 2) The contractor shall ensure all laboratory analysis is performed by a firm certified and in good standing with Maine s Health & Environmental Laboratory certification program and acceptable to the City. If, during the term of this agreement the laboratory s certification status changes, the contractor will be responsible for locating and utilizing an alternate laboratory certified for this work, which is also acceptable to the City. Subcontractors for actual sampling are acceptable, provided the subcontractor meets the requirements of the Facility s EMP. Subcontractors for additional laboratory analysis of samples must be in compliance and maintain compliance with Maine s Health & Environmental Laboratory certification program. In the event subcontractors are utilized for analysis of sample parameters, chain of custody forms will be utilized to document the transfer of samples. 3) Monthly sampling and field analysis will be performed on samples of leachate and liquid from the leak detection system. 4) Tri-annual sampling from all sample sites will occur during the following intervals: a. Summer Sampling: July/August b. Fall Sampling: October/November c. Spring Sampling: March/April 5) All sample collection and analysis shall be performed in accordance with the Facility s EMP, dated December 21, 1999, revised July 2009, and all applicable State and Federal regulations. In the event the requirements of the EMP contradict State and/or Federal regulations, this observation will be brought to the attention of the Superintendent who will provide guidance on how to proceed. 12

13 6) If a sample cannot be obtained from a given monitoring site, the contractor will contact the Superintendent and either arrange for sampling at a separate date or deduct the cost of sampling and analysis of the sample point from the invoice. The cost deduction will be based on the contractor s unit cost for sample collection and analysis. 6) A report, which contains the lab results from each sampling site collected during a monitoring event shall be submitted to the Solid Waste Superintendent within 30 working days from the last day of sample collection. The lab results will be recorded and forwarded to the Superintendent on two (2) separate compact discs (CDs). The first data set will be recorded on a Microsoft Excel spreadsheet. The City will provide the Contractor with a copy of the spreadsheet, which contains the format to be utilized no later than 30 days following the award of this contract. The second data set will be recorded on a Microsoft Excel spreadsheet in accordance with DEP s Electronic Database Deliverable format (EDD). In addition, both a hard copy of lab results and the completed field report forms will be provided to the Superintendent, at this time. 7) The Field Inspection Form will be developed and provided by the contractor. This inspection form must be approved by the Superintendent prior to implementation. All Field notes documenting each sampling event must be written legibly. 8) The contractor selected to complete the Scope Of Work must submit a Health & Safety Plan for their personnel who are involved in sample collection at the Facility, which is acceptable to the Superintendent, prior to the first monitoring round. 9) The contractor will adhere to the following QA/QC guidance during each sampling event: a. One equipment blank (final rinsate blank) will be collected and analyzed for the parameters listed in Table 2B of Appendix B for each piece of non-dedicated sampling equipment used at the end of each sampling event; b. One trip blank will be collected and analyzed for the VOC parameter listed in Table 2B of Appendix B per cooler or shipping container each time samples are transported to the laboratory for VOC analysis; c. One duplicate for every ten samples collected will be analyzed for the parameters listed in Table 2B of Appendix B over the course of consecutive sampling events. (The duplicate sample identification must be coded such that its origin is unknown to the laboratory.); d. All non-dedicated equipment and tubing must be decontaminated by rinsing three times with distilled or de-ionized water prior to sampling a new monitoring location or storing the equipment; e. All sampling and monitoring equipment will be stored in a manner to avoid and prevent contamination or becoming contaminated by any other source. When not in use, equipment will be individually protected and stored in a locked area; f. A continuous chain of custody will be maintained for each sample and will include identical information from each sample label, as well as sample type, 13

14 number and size of containers, name and signature of collector and person(s) receiving the sample, and date of sample receipt; g. All collected samples must be stored in coolers (approximately 4 o C) until they are delivered to the laboratory for analysis. Samples will be packaged to avoid breaking containers and deleterious conditions during transport; h. The laboratory performing sample analysis will be capable of measuring the specified detection limits, which do not exceed one half of the MCL/MEG for each respective parameter described in Table 2B of Appendix B; and i. The laboratory designated for analysis of samples will utilize standard accepted practices for their laboratory procedures and internal quality control. The laboratory will supply all appropriate containers and necessary chemical preservatives. The appropriate analytical methods and detection limits, described above, will be followed and the duplicate sample(s) will provide a check on the laboratory analytical quality. Task 1 Sample Collection and Analysis Secure Landfill 1) In their proposal, the contractor shall provide the City with a Not to Exceed budget estimate to complete the Scope of Service, Sample Collection & Analysis Secure Landfill, which represents the contractors best judgment as to the level of effort required to complete this task. In support of their proposal, the contractor shall provide the City with a breakdown of the estimated cost to complete each task (which includes sample collection, field analysis, sample analysis (based on laboratory unit cost), report preparation and other basic costs) described in the Scope of Service, Sample Collection & Analysis - Secure Landfill. Billings shall be based on actual accrued time and expenses in accordance with the schedule of fees. 2) The contractor will be responsible for locating and collecting samples from the following monitoring wells: a. MW-1 b. MW-2 c. MW-3 d. MW-4 e. MW-5 f. MW-6 g. MW-7 h. MW-8 i. MW-9 j. MW-10 k. MW-11 l. MW-12 (refer to the site drawing in Appendix D for the location of these sample points) 3) In order to reduce the potential for cross-contamination between monitoring wells, the contractor will collect samples in the order presented in Table 2A of Appendix A. This 14

15 order of sampling shall be followed consistently through each sampling event. In general, the monitoring well sampling order will be from background to downgradient locations. 4) Upon arrival at each monitoring well, the contractor shall note the physical conditions of each monitoring well (condition of the standpipe, presence of a working padlock, surface seal condition, damage due to vandalism, etc.) and note this on the field inspection form. In addition, the following information will be recorded on each field inspection form: m. Name of sampler; n. Date and time of sampling; o. Climatic conditions; p. Monitoring well identification; q. Well depth; r. Purge time, rate and total volume; s. Field analysis data (described as Item 10); and t. Field observations during sampling event. 5) Prior to purging the well, the contractor will obtain a static water level reading, which must be measured and recorded on the field inspection form to the nearest 100 th of a foot through the use of standard techniques. The contractor will exercise care when inserting the water level probe into the water column so as to minimize disturbances of the stagnant water column above the screened interval. Non-dedicated water level probes must first be decontaminated by rinsing at least three times with de-ionized or distilled water, prior to placement in the well. 6) The contractor will utilize low-flow sampling techniques when collecting groundwater samples to reduce potential sampling-related influences on the physical and chemical characteristics of the aquifer. The EPA recommended procedures for low-flow are provided in Appendix C. The contractor will utilize a variable speed peristaltic pump to establish low flow rates (i.e., 0.1 to 0.5 L/min) at monitoring locations with stabilized water level head differentials less than 30 feet. The four monitoring locations in the Secure Landfill with head differentials approaching depths greater than 30 feet (MW-4, MW-8, MW-9 and MW-12) may require use of a variable speed, positive displacement submersible pump capable of achieving low flow rates. 7) The contractor will ensure the pump intake at each monitoring location is within the screened interval of the monitoring well to be sampled (tubing should be dedicated to each monitoring location to ensure consistent positioning within the screened interval). Refer to Appendix A for well depths and screen intervals for each monitoring location. The contractor will utilize the following procedure to reduce the potential for drawdown within the well: a. The flow rate should be stabilized as soon as possible in each monitoring location to avoid severe drawdown and subsequent imposed gradients. b. In monitoring locations where a peristaltic pump may be used to achieve low flow rates, an appropriate length of tubing will be dedicated at each location. The dedicated tubing and accompanying monitor devices (i.e., water level 15

16 probe) will be inserted into the well casing in such a way that minimizes disturbance to the stagnant water column above the screened interval. Tubing will remain in the well casing between monitoring rounds to avoid disturbing the water level in the well. c. In monitoring locations requiring a submersible pump to achieve low flow rates, the pump and monitoring devices will be inserted into the well casing through the stagnant water column slowly to minimize the amount of disturbance in the stagnant water column. 8) The contractor will commence sample collection at the same flow rate used to purge the well when the following purge stabilization criteria are satisfied: a. specific conductance stabilizes within 3% of the reading range for 3 consecutive readings at 5 minute intervals; b. dissolved oxygen and turbidity stabilize within 10% of the reading range for 3 consecutive readings at 5 minute intervals; c. ph values are within 0.1 standard unit of the reading range for 3 consecutive readings at 5 minute intervals; and d. the water level is stabilized. 9) The contractor will direct or dispose of the purge water in a manner that does not crosscontaminate adjacent wells. Purge water will be directed at least five feet away from the standpipe to avoid saturation of the area surrounding the monitoring location. 10) The contractor will record the following field parameters, on the field inspection form, during the purge stabilization period: a. Static water elevation; b. Turbidity; c. Specific conductance; d. Temperature; e. ph; f. Dissolved oxygen; and g. Any field observations, such as color, odor, visible surface sheen, etc. The contractor will calibrate all field test equipment at the beginning of each sampling day, according to the manufacturer s specifications. Calibration data must be recorded on the field inspection form. 11) Once purge stabilization has been completed and the field parameters have been recorded, the contractor will commence sample collection from the monitoring well. The monitoring parameters to be sampled for are listed in Table 1 of Appendix B. The order of sample collection for the Secure Landfill has been provided on Table 2B of Appendix B. In addition, the contractor will follow the sample analysis procedures specified in Table 2B of Appendix B. In the event additional parameters are required for analysis, the contractor will follow the guidance provided in Table 2B of Appendix B. All samples collected must be unfiltered, collected in a manner that produces the least possible sampling-induced 16

17 turbidity and carefully directed into the respective containers. The contractor will be responsible for providing: a. containers specified in the analytic method for the samples to be collected; b. ensuring samples are preserved and maximum hold times for each parameter are maintained in accordance with the analytical method, and; c. containers (with caps) are labeled with indelible ink with the following information - sample identification number, date and time of collection, and parameters required for analysis. Task 2 Sample Collection and Analysis Attenuated Landfill 1) In their proposal, the contractor shall provide the City with a Not to Exceed budget estimate to complete the Scope of Service, Sample Collection & Analysis Attenuated Landfill, which represents the contractors best judgment as to the level of effort required to complete this task. In support of their proposal, the contractor shall provide the City with a breakdown of the estimated cost to complete each task (which includes sample collection, field analysis, sample analysis (based on laboratory unit cost), report preparation and other basic costs) described in the Scope of Service, Sample Collection & Analysis Attenuated Landfill. Billings shall be based on actual accrued time and expenses in accordance with the schedule of fees. 2) The contractor will be responsible for collecting samples from the following monitoring wells: a. MW-101 b. MW-103 c. MW-205A d. MW-205B (Bedrock) e. MW-206 f. MW-207 g. MW-303B (Bedrock) h. MW-303C (Bedrock) (refer to the site drawing in Appendix D for the location of these sample points) 3) In order to reduce the potential for cross-contamination between monitoring wells, the contractor will collect samples in the order presented in Table 2A of Appendix A. This order of sampling shall be followed consistently through each sampling event. In general, the monitoring well sampling order will be from background to down gradient locations. 4) Upon arrival at each monitoring well, the contractor shall note the physical conditions of each monitoring well (condition of the standpipe, presence of a working padlock, surface seal condition, damage due to vandalism, etc.) and note this on the field inspection form. In addition, the following information will be recorded on each field inspection form: a. Name of sampler; 17

18 b. Date and time of sampling; c. Climatic conditions; d. Monitoring well identification; e. Well depth; f. Purge time, rate and total volume; g. Field analysis data (described as Item 10); and h. Field observations during sampling event. 5) Prior to purging the well, the contractor will obtain a static water level reading, which must be measured and recorded on the field inspection form to the nearest 100 th of a foot through the use of standard techniques. The contractor will exercise care when inserting the water level probe into the water column so as to minimize disturbances of the stagnant water column above the screened interval. Non-dedicated water level probes must first be decontaminated by rinsing at least three times with de-ionized or distilled water, prior to placement in the well. 6) The contractor will utilize low-flow sampling techniques when collecting groundwater samples to reduce potential sampling-related influences on the physical and chemical characteristics of the aquifer. The EPA recommended procedures for low-flow are provided in Appendix C. The contractor will utilize a variable speed peristaltic pump to establish low flow rates (i.e., 0.1 to 0.5 L/min) at monitoring locations with stabilized water level head differentials less than 30 feet. The two monitoring locations in the Attenuated Landfill with head differentials approaching depths greater than 30 feet (MW-205A & MW- 205B) may require use of a variable speed, positive displacement submersible pump capable of achieving low flow rates. 7) The contractor will ensure the pump intake at each monitoring location is within the screened interval of the monitoring well to be sampled (tubing should be dedicated to each monitoring location to ensure consistent positioning within the screened interval). Refer to Appendix A for well depths and screen intervals for each monitoring location. The contractor will utilize the following procedure to reduce the potential for drawdown within the well: a. The flow rate should be stabilized as soon as possible in each monitoring location to avoid severe drawdown and subsequent imposed gradients. b. In monitoring locations where a peristaltic pump may be used to achieve low flow rates, an appropriate length of tubing will be dedicated at each location. The dedicated tubing and accompanying monitor devices (i.e., water level probe) will be inserted into the well casing in such a way that minimizes disturbance to the stagnant water column above the screened interval. Tubing will remain in the well casing between monitoring rounds to avoid disturbing the water level in the well. c. In monitoring locations requiring a submersible pump to achieve low flow rates, the pump and monitoring devices will be inserted into the well casing through the stagnant water column slowly to minimize the amount of disturbance in the stagnant water column. 18

19 8) The contractor will commence sample collection at the same flow rate used to purge the well when the following purge stabilization criteria are satisfied: a. specific conductance stabilizes within 3% of the reading range for 3 consecutive readings at 5 minute intervals; b. dissolved oxygen and turbidity stabilize within 10% of the reading range for 3 consecutive readings at 5 minute intervals; c. ph values are within 0.1 standard unit of the reading range for 3 consecutive readings at 5 minute intervals; and d. the water level is stabilized. 9) The contractor will direct or dispose of the purge water in a manner that does not crosscontaminate adjacent wells. Purge water will be directed at least five feet away from the standpipe to avoid saturation of the area surrounding the monitoring location. 10) The contractor will record the following field parameters, on the field inspection form, during the purge stabilization period: a. Static water elevation; b. Turbidity; c. Specific conductance; d. Temperature; e. ph; f. Dissolved oxygen; and g. Any field observations, such as color, odor, visible surface sheen, etc. The contractor will calibrate all field test equipment at the beginning of each sampling day, according to the manufacturer s specifications. Calibration data must be recorded on the field inspection form. 11) Once purge stabilization has been completed and the field parameters have been recorded, the contractor will commence sample collection from the monitoring well. The monitoring parameters to be sampled for are listed in Table 1 of Appendix B. The order of sample collection for the Attenuated Landfill has been provided on Table 2B of Appendix B. In addition, the contractor will follow the sample analysis procedures specified in Table 2B of Appendix B. In the event additional parameters are required for analysis, the contractor will follow the guidance provided in Table 2B of Appendix B. All samples collected must be unfiltered, collected in a manner that produces the least possible sampling-induced turbidity and carefully directed into the respective containers. The contractor will be responsible for providing: a. containers specified in the analytic method for the samples to be collected; b. ensuring samples are preserved and maximum hold times for each parameter are maintained in accordance with the analytical method, and; c. containers (with caps) are labeled with indelible ink with the following information - sample identification number, date and time of collection, and parameters required for analysis. 19

20 Task 3 Sample Collection and Analysis Surface Water 1) In their proposal, the contractor shall provide the City with a Not to Exceed budget estimate to complete the Scope of Service, Sample Collection & Analysis Surface Water, which represents the contractors best judgment as to the level of effort required to complete this task. In support of their proposal, the contractor shall provide the City with a breakdown of the estimated cost to complete each task (which includes sample collection, field analysis, sample analysis (based on laboratory unit cost), report preparation and other basic costs) described in the Scope of Service, Sample Collection & Analysis Surface Water. Billings shall be based on actual accrued time and expenses in accordance with the schedule of fees. 2) There are three surface sample locations within the Facility. They are located along a small stream which runs from the northern boundary of the Facility through a 54 RCP culvert under the Attenuation Landfill and exits in the southwestern corner of the property. Two upstream locations and one downstream location have been identified for sampling purposes. The sample locations (SW-1, SW-2 and SW-3) are shown on the site drawing provided in Appendix D. The contractor will be responsible for locating and collecting samples from: 3) SW-1 4) SW-2 5) SW-3 The contractor will obtain grab samples from each surface water location in a manner that will produce representative and non-contaminated samples. When collecting samples from shallow water, the contractor will minimize the amount of turbidity present in the sample and will NOT include bottom sediment from the stream. The samples collected will be unfiltered, and will be carefully emptied into the respective sample containers designated for the location. 3) The contractor will collect surface water samples in order from downstream to upstream locations, as described in Table 2A of Appendix A. The order of collection for the monitoring parameters from each sampling location will follow the parameter order presented in Table 2B of Appendix B for the Attenuation Landfill. 4) Upon arrival at each surface water sample site, the contractor shall note the physical conditions of the area (rain event within the past 48 hours, disturbance to the area, approximate water level of the stream, etc.) and note this on the field inspection form. The field notes must be written legibly on the form. In addition, the following information will be recorded on each field inspection form: d. Name of sampler; e. Date and time of sampling; f. Climatic conditions; g. Sample site identification; h. Stream depth; i. Purge time, rate and total volume; 20

21 j. Field analysis data (described in the following paragraph); and k. Field observations during sampling event. 5) The contractor will collect and perform analysis on samples obtained for the following field parameters: a. Stream depth; b. Turbidity; c. Specific conductance; d. Temperature; e. ph; f. Dissolved oxygen; g. Approximate rate of stream flow and h. Any field observations, such as color, odor, visible surface sheen, etc. The results of this analysis will be recorded on the field inspection form. In addition, the contractor will calibrate all field test equipment at the beginning of each sampling day, according to the manufacturer s specifications. The contractor will record all calibration data on the field inspection form. 6) Once the field parameters have been recorded, the contractor will commence sample collection. The order for sample collection for the Surface Water Sites has been provided on Table 2B in Appendix B. All samples collected must be unfiltered, collected in a manner that produces the least possible sampling-induced turbidity and carefully directed into the respective containers. The contractor will be responsible for providing: a. containers specified in the analytic method for the samples to be collected; b. ensuring samples are preserved and maximum hold times for each parameter are maintained in accordance with the analytical method, and; c. containers (with caps) are labeled with indelible ink with the following information - sample identification number, date and time of collection, and parameters required for analysis. Task 4 Sample Collection and Analysis Water Supply Wells 1) In their proposal, the contractor shall provide the City with a Not to Exceed budget estimate to complete the Scope of Service, Sample Collection & Analysis Water Supply Wells, which represents the contractors best judgment as to the level of effort required to complete this task. In support of their proposal, the contractor shall provide the City with a breakdown of the estimated cost to complete each task (which includes sample collection, field analysis, sample analysis (based on laboratory unit cost), report preparation and other basic costs) described in the Scope of Service, Sample Collection & Analysis Water Supply Wells. Billings shall be based on actual accrued time and expenses in accordance with the schedule of fees. 2) Two residential water supply wells are located proximate to the Lewiston Solid Waste Facility and are, therefore, sampled as part of the groundwater monitoring program. Annually, (as part of the Spring March-April - monitoring round for the Secure & 21

22 Attenuated landfills), the contractor will collect a water sample from the following residential properties - the residence located at 359 River Road, which is approximately 1,700 linear feet north of the facility, and the residence located at 463 River Rd. which is southwest from the Attenuated landfill. In order to obtain a representative sample, the contractor will collect a water sample in accordance with the following procedure - 1. Run water from the exterior spigot, located on the residential structure, for 5 to 10 minutes to purge water lines. 2. Collect a 2-liter sample to run through peristaltic pump to screen for the field parameters described in item #3, below (i.e., ph, specific conductance, temperature), and estimate the approximate flow rate and record all information on the field sheet. a. Sample analysis will include the parameters listed in Table 2B of Appendix B Attenuated landfill, with the exception of VOC s. The contractor will collect samples for the parameters described in item #2, above. In addition, if this sample site is connected to the municipal water supply at some time in the future, the sampling for these wells will be deleted. 3) Upon arrival at the sample site, the contractor shall note the physical conditions of the area (condition of the well, condition of plumbing, addition of water softeners, pressure tanks, treatment systems, etc.) and document this on the field inspection form. In addition, the following information will be recorded on each field inspection form: a. Name of sampler; b. Date and time of sampling; c. Climatic conditions; d. Sample site identification; e. Field analysis data (described in the following paragraph); and f. Field observations during sampling event. The contractor will collect and perform analysis on samples obtained for the following field parameters: a. Specific conductance; b. Temperature; c. ph; d. Approximate rate of flow and e. Any field observations, such as color, odor, visible surface sheen, etc. The results of this analysis will be recorded on the field inspection form. In addition, the contractor will calibrate all field test equipment at the beginning of each sampling day, 22

23 according to the manufacturer s specifications. The contractor will record all calibration data on the field inspection form. The samples collected will be unfiltered, and will be carefully emptied into the respective sample containers designated for the location. Task 5 Sample Collection and Analysis Leachate & Leachate Detection System 1) In their proposal, the contractor shall provide the City with a Not to Exceed budget estimate to complete the Scope of Service, Sample Collection & Analysis Leachate & Leachate Detection System, which represents the contractors best judgment as to the level of effort required to complete this task. In support of their proposal, the contractor shall provide the City with a breakdown of the estimated cost to complete each task (which includes sample collection, field analysis, sample analysis (based on laboratory unit cost), report preparation and other basic costs) described in the Scope of Service, Sample Collection & Analysis Leachate & Leachate Detection System. Billings shall be based on actual accrued time and expenses in accordance with the schedule of fees. 2) There are five sample locations within the Facility for collection of leachate and liquid from the Leak Detection System (LDS). Samples for leachate are obtained from MH-6 lower (prior to entering the leachate equalization basin) and MH-14 (immediately after discharge from the leachate equalization basin). Samples (when liquid is available) from the LDS are obtained from MH-6 upper, LD-1 and LD-2. In the event there is a flow from either LD- 1 or LD-2, the contractor will notify the Superintendent, prior to obtaining samples. The locations of these five sites are shown on the site drawing provided in Appendix D. The contractor will be responsible for locating and collecting samples from these monitoring points. 3) The contractor will obtain grab samples from each sample location in a manner that will produce representative and non-contaminated samples. Methods developed by the contractor to obtain leachate and LDS samples will be approved by the Superintendent prior to implementation. The samples collected will be unfiltered, and will be carefully emptied into the respective sample containers designated for the location. 4) On a monthly basis, the contractor will obtain samples and perform the following field monitoring procedures for each of the leachate and LDS (based of the presence of flow within the sample point) monitoring sites. Upon arrival at each sample site, the contractor shall note the physical conditions of the area (rain event within the past 48 hours, disturbance to the area, conditions of the manhole, approximate flow within the pipe, etc.) and note this on the field inspection form. In addition, the following information will be recorded on each field inspection form: a. Name of sampler; b. Date and time of sampling; c. Climatic conditions; d. Sample site identification; e. Sample type (leachate or LDS sample) 23

24 f. Field analysis data (described in the following paragraph); and g. Field observations during sampling event. The contractor will collect and perform analysis on samples obtained for the following field parameters: a. Turbidity; b. Specific conductance; c. Temperature; d. ph; e. Eh; f. Dissolved oxygen; g. Approximate rate of flow and h. Any field observations, such as color, odor, visible surface sheen, etc. The results of this analysis will be recorded on the field inspection form. In addition, the contractor will calibrate all field test equipment at the beginning of each sampling day, according to the manufacturer s specifications. The contractor will record all calibration data on the field inspection form. 5) On a tri-annual basis, the contractor will collect leachate and LDS samples for analysis of the parameters listed in Table 1 of Appendix B, in addition to the field parameters. Annually, during the Spring monitoring round, the contractor will collect additional samples for analysis of the following monitoring parameters: a. VOC s, b. Cobalt, c. Cyanide, d. Copper, e. Antimony, f. Thallium, g. Beryllium, and h. Zinc The contractor will follow the order of sample collection for leachate and LDS samples as provided on Table 2B of Appendix B. The contractor will also follow the sample analysis procedures specified in Table 2B of Appendix B. In the event additional parameters are required for analysis, the contractor will follow the guidance provided in Table 2B of Appendix B. All samples collected must be unfiltered, collected in a manner that produces the least possible sampling-induced turbidity and carefully directed into the respective containers. The contractor will be responsible for providing: a. containers specified in the analytic method for the samples to be collected; b. ensuring samples are preserved and maximum hold times for each parameter are maintained in accordance with the analytical method, and; c. containers (with caps) are labeled with indelible ink with the following information - sample identification number, date and time of collection, and parameters required for analysis. 24

25 10.9 ADDITIONAL TECHNICAL ASSISTANCE: In addition to the work described above, the City of Lewiston is requesting the bidding Contractor provide a schedule of hourly fees for general consultation. General consultation may be required from time to time in such areas as daily landfill operations, regulatory matters, and other matters germane to solid waste management IMPLEMENTATION OF CONTRACT: Upon acceptance of the bid and approval of the proposal Technical Assistance Environmental Monitoring & Sample Analysis, the Contractor shall begin work in accordance with the terms of these Contract Documents on July 1, The Contractor shall perform work necessary to provide the City with an annual report, environmental monitoring and sample analysis as described in the Scope of Service for a term of five (5) years COMPLAINT RESOLUTION: If, during the execution of their duties to fulfill the terms of the Contract Documents, the Contractor or their staff are confronted with an issue or concern, which they feel is outside the terms of this agreement, the Contractor will notify the Public Works Director or his/her designee, promptly, who, in turn, will respond to the concern in a timely manner. The City is committed to the successful performance of this Contract and will, as needed, enter into good faith negotiations with the Contractor to address their issues to the satisfaction of both parties CONTRACT ADMINISTRATION: The City, through its Public Works Director, or his/her designee, shall independently administer the provisions of this Contract. The work, as described in these Contract Documents must all be in a manner satisfactory to the Director. Decisions of the Director will be final and a condition precedent to the right of the Contractor to receive payment under his/her respective Contract. The City reserves the right to add or delete portions of the work required under this Contract, using unit prices established in the Proposal. The Contractor s attention is directed to Sections 22.5 and 22.6 of the Standard Specifications Extra Work and Reduction of Work respectively. If no unit prices exist, a change order must be negotiated between the City of Lewiston and the Contractor. The Contractor shall note and respond to all requirements specified in the Standard Specifications as described in Division 20. If additional information / clarification is required related to this Project, please contact Rob Stalford Solid Waste Superintendent at

26 STANDARD SPECIFICATION DIVISION 20 GENERAL PROVISIONS 20.0 SCOPE: These Standard Specifications and Addenda, if any, are to govern Technical Assistance Environmental Monitoring & Sample Analysis from 2014 through 2019 and other related work, for the City of Lewiston, and they shall become part of any contract with the City for the completion of said work. Provisions of these Specifications shall be modified or changed only in writing. These Standard Specifications will be amended with Supplemental Specifications as necessary, and with the Contract Plans. The Supplemental Specifications delineate the particular project to which the Contract Documents pertain. Should any discrepancy be found to exist between the Standard Specifications and the Supplemental Specifications, the Supplemental Specifications shall govern DEFINITIONS: a) City: Whenever the term City, or a pronoun in its stead, is used, it shall mean the City of Lewiston. b) Contract Documents: Whenever the term Contract Documents, or a pronoun in its stead, is used, it shall mean and include, but not necessarily be limited to, these items: The Notice to Contractors, the Proposal, the Contract, the Supplemental Specifications, the Standard Specifications, the Contract Plans, the Request for Proposal, any other documents included with these specifications and attached thereto, and any Addenda to the above issued prior to the date of this Contract. c) Contractor: Whenever the term Contractor, or a pronoun in its stead, is used, it shall mean the person or persons, or co-partnership or corporation which has entered into this agreement or their legal representative. d) Director Budget / Purchasing: Whenever the term Director Budget / Purchasing, or a pronoun in its stead, is used, it shall mean the Director of Budget / Purchasing for the City of Lewiston. e) Owner: Whenever the term Owner, or a pronoun in its stead, is used, it shall mean the City of Lewiston, acting through its designated officials and/or employees. f) Director of Public Works or Director: Whenever the term Director of Public Works, Director, or a pronoun in their stead, is used, it shall mean the Director of Public Works of the City of Lewiston or his/her assistant or inspectors acting under him, limited to the particular duties entrusted to them. g) Superintendent of Solid Waste or Superintendent: Whenever the term Superintendent of Solid Waste, Superintendent, or a pronoun in their stead, is used, it shall mean the Superintendent of Solid Waste of the City of Lewiston or his/her assistant or inspectors acting under him/her, limited to the particular duties entrusted to them. 26

27 h) Specification: Whenever the term Specification, or a noun in its stead, is used, it shall mean and include the Standard Specifications as herein set forth and any Supplemental Specifications included in the Contract Documents. i) Contract Plans: Whenever the term Contract Plans, or a pronoun in their stead, is used, it shall mean and include all the drawings, graphic representations, diagrams and any notes or explanations thereon supplied to the Contractor before the date of this Contract. j) Lump Sum Bid Price: Whenever the term Lump Sum Bid Price, Lump Sum Bid, Lump Sum, or a pronoun in their stead, is used, it shall mean the amount of money mutually agreed to by the Contractor for the labor, machinery, equipment, tools, apparatus, supplies, and other means of performing all the work and performing all the services called for by the Contract Documents except for those items specifically stated as being considered extra work or for which unit prices have been established in the Contract and Proposal. k) Unit Bid Price: Whenever the term Unit Bid Price, Unit Bid, Unit Price, or a pronoun in their stead, is used, it shall mean the amount of money mutually agreed to by the Contractor as full payment to the Contractor to furnish all necessary labor, materials, and equipment (except that which is specifically excluded in the Supplemental and Standard Specifications, and the Contract Plans) necessary to do one unit of work INSURANCE AND LIABILITY: The Contractor shall take all responsibility of the work and take all precautions for preventing injuries to persons and property in or about the work; shall bear all losses resulting to him/her on account of the amount or character of the work, or because the nature of the land in or on which the work is done is different from what was estimated or expected on account of the weather, elements or other cause; and he/she shall assume the defense of, and indemnify and save harmless, the City of Lewiston and its officers, agents and servants, from all claims relating to labor and materials furnished for the work; to inventions, patents and patent rights used in doing the work; to injuries to any person or corporation received or sustained by or from the Contractor and his/her employees in doing the work, or in consequence of any improper materials, implements or labor used therein; and to any act, omission or neglect of the Contractor and his/her employees therein. The Contractor shall procure and maintain for the life of this Contract insurance of the types and to the limits specified below. Certificates of such insurance showing policies and adequacy of protection shall be filed with the Director Budget / Purchasing for his/her approval before permission to commence work will be granted. INSURANCE REQUIREMENTS (a) Workmen s Compensation Insurance for all individuals employed at the site of the project; and, in case any work is sublet, the Contractor shall require the sub-contractor similarly to provide coverage for the latter s employees unless such employees are covered 27

28 by the protection afforded the Contractor; all coverage shall be in accordance with State of Maine laws in effect and the requirements of the Industrial Accident Commission. (b) General Liability Insurance with minimum limits of liability for bodily injury in the amount of $500,000 combined single unit and minimum limits of liability for property damage in the amount of $100,000 combined single limit. General liability coverage shall include Owners or Contractors Protective, Product and Completed Operations, Comprehensive, Explosion (X), Collapse (C), and Underground (U) coverage. (c) Automotive Liability Insurance with minimum limits of liability for bodily injury in the amount of $500,000 for each occurrence and minimum limits of liability for property damages in the amount of $100,000. Automobile liability coverage shall include owned, hired and nonowned vehicles DISPUTE RESOLUTION COSTS AND EXPENSES: In the event of any dispute between or involving the City of Lewiston and Contractor, whether resolved by arbitration, litigation or some other mechanism of dispute resolution, in the event that the City, either jointly or collectively, shall be a prevailing party, Contractor shall reimburse the City for their attorney s fee and costs reasonably incurred in connection with the resolution of the dispute LAWS AND REGULATIONS: The Contractor shall keep himself/herself informed of all existing and future State and Federal laws and municipal ordinances and regulations which in any way affect those engaged or employed in the work, or the materials used in the work; or in any way affect the conduct of the work and of all orders and decrees of bodies of tribunals having any jurisdiction is discovered in the Plans or Specifications or Contract for this work in relation to any such law, ordinance, regulation, order or decree, he/she shall forthwith report the same to the Director in writing. He/she shall at all times himself/herself observe and comply with all such existing and future laws, ordinances, regulations, orders and decrees; and shall protect and indemnify the City and its officers and agents against any claim or liability arising from or based on the violation of any such law, ordinance, regulation, order or decree, whether by himself/herself or his/her employees ESTIMATES AND PAYMENTS: The Director may, if he/she deems it expedient to do so, cause estimates to be made of work completed and he/she may approve payments to be made to the Contractor, based on these estimates. Payment may at any time be withheld if the work is not proceeding in accordance with the provisions of this Contract. The Director may at his/her option retain, temporarily or permanently, a smaller amount than aforesaid, and may approve payment to the Contractor, either temporarily or permanently from time to time during the progress of the work, of such portion of the retained amount as he/she may deem prudent. The City, may keep any money which would otherwise be payable at any time hereunder, and apply the same, or so much as may be necessary therefore, to the payment of any 28

29 expenses, losses, or damage incurred by the City and determined as herein; and may retain, until all claims are settled, so much of such money as the Director shall be of the opinion will be required to settle all claims against the City, its officers, agents or servants FINAL ESTIMATE AND PAYMENT: It is further mutually agreed that whenever, in the opinion of the Director or his/her designee, the Contractor shall have completely performed all the work embraced in this Contract, the Director shall proceed with all reasonable diligence to measure the work and shall make out the final estimate for the same and shall certify the same in writing; and his/her certificate shall state the whole amount of the payments previously paid and the amount retained in all previous estimates. Within the term of thirty (30) days after the date of such final estimate, the City will pay to the said Contractor the amount due. All prior partial estimates and payments shall be subject to correction in the final estimate and payment. Provided that nothing herein contained shall be construed to affect the right of the City by the Director hereby reserved, to reject the whole or any portion of the aforesaid work should the said certificate or certificates be found or known to be inconsistent with the terms of this Agreement or otherwise improperly given LAST PAYMENT TO TERMINATE LIABILITY OF CITY: No person or corporation other than the signer of this Contract as Contractor now has any interest hereunder, and no claim shall be made or be valid; and neither the City, nor its Mayor, nor any member or agent thereof, shall be liable for, or be held to pay any money, except as provided for in Sections 20.5, 20.6, 21.2, and 22.6 of the Standard Specifications and in the Contract. The Acceptance by the Contractor of the last payment aforesaid shall operate as and shall be a release to the City, its Mayor, and every member or agent thereof, from all claim or liability to the Contractor for anything done or furnished for, or relating to the work, or for any act or neglect of the City, or of any person relating to or affecting the work, except the claim against the City for the remainder, if any there be of the amount kept or retained as provided for in Section SITE INVESTIGATION: The Contractor shall examine the Plans, Specifications and site of the work and from his/her own investigation, determine the nature and location of the work, the general and local conditions, particularly those bearing on access, transportation, quality and quantity of services required, and all other aspects of the work, machinery and services required to complete the project as required by the Contract Documents. The City will not be responsible for any understanding or representation made by any City employee during or prior to negotiation and execution of the Contract, unless such understanding or representation shall be in writing and become a part of the Contract Documents. 29

30 20.9 COMMENCEMENT OF WORK: The Contractor agrees to commence the work required in the Contract Documents within ten (10) days after the signing of the Contract, unless otherwise specified in the Supplemental Specifications or directed by the Director; and at his/her own cost and expense do and complete all the work and furnish all the labor, machinery, tools and materials, except as specified in the Supplemental Specifications, and to do everything required to fulfill the terms of these Contract Documents for the City of Lewiston as described in the Contract Documents TIME AND ORDER OF DOING WORK: The Contractor agrees that the work shall be commenced and carried on at such points and in such order of precedence and at such times and seasons as may from time to time be directed by the Superintendent. It is further agreed that no work shall be done under this Contract on Saturdays or Sundays or on days declared by the State Legislature as Legal Holidays, except as directed by the Director; nor shall any work be done at night except as directed by the Director. The Contractor shall make his/her work week conform to that of the City s Public Works Department COMPETENT PERSONNEL TO BE EMPLOYED: The Contractor shall employ only competent personnel to do the work; and whenever the Director shall notify the Contractor, in writing, that any person on the work is, in his/her opinion, incompetent, unfaithful, disorderly or otherwise unsatisfactory, such person shall be discharged from the work and shall not again be employed on it except with the consent of the Director NOT TO SUBLET OR ASSIGN: The Contractor shall give his/her personal attention constantly to the faithful prosecution of the work, shall keep the same under his/her personal control and shall not assign, by power of attorney or otherwise, nor sublet the work or any part thereof, without the previous written consent of the Director; and shall not, either legally or equitably, assign any of the money payable under this Agreement or his/her claim thereto, unless by and with the like consent of the Director DIRECTIONS AND EXPLANATIONS, CORRECTIONS OF ERRORS: The Plans and Specifications are understood to be explanatory of each other, but should any discrepancy appear or any misunderstanding arise as to the import of anything contained in either of them, the parties hereto further agree that the explanation and decision of the Director shall be final and binding on the Contractor; and all directions or explanations required or necessary to complete any of the provisions of this Contract and these 30

31 Specifications and give them due effect shall be given by the Director. Correction of any error in the Plans or Specifications may be made by the Director, when such correction is necessary for the proper fulfillment of the intention of such Plans or Specifications, the effect of such correction to date from the time that the Director gives due notice in writing to the Contractor DUTY TO NOTIFY DIRECTOR IF AMBIGUITIES DISCOVERED: The Contractor shall not take advantage of any ambiguity, error, omission, conflict, or discrepancy ( ambiguity, etc. ) contained in the Plans and Specifications that may significantly affect the cost, quality, conformity, or timeliness of the work. If the Contractor discovers any such ambiguity, etc., for which the Contractor may seek adjustments to compensation, time, or other Contract requirements, the Contractor shall provide a written notice stating the nature of the ambiguity, etc. within 48 hours of discovering or being notified of the ambiguity and before performing any work related to the ambiguity, etc., as provided in Section 21.5 Early Negotiation. Failure to provide such written notice in compliance with the contract shall constitute a waiver of all claims related to the ambiguity, etc EARLY NEGOTIATION: (a) Notice Required: When the Contractor becomes aware of facts or circumstances that may cause the Contractor to seek additional compensation, time, or any other change in the requirements of the Plans and Specifications ( Issue ), then the Contractor shall notify the Director in writing within 48 hours of identification of the issue and at least 48 hours before commencing any part of the Work relating to the Issue. The notice must describe the basic nature and extent of the Issue. Such notice may be verbal only if confirmed in writing in one of the two following ways: (A) if a Progress Meeting is held within 14 days of the date that the Issue became known, such Notice may be confirmed with an entry in the Progress Meeting minutes. Such entry must describe the basic nature and extent of the Issue. (B) Otherwise, the Contractor shall confirm a verbal notice by delivering to the Director, within 14 days of the date the Issue arose, a Written Notice that describes the basic nature and extent of the Issue. The written notice or confirmation will be known as a Notice of Issue for Consideration. The Contractor will not be entitled to any additional compensation, time, or any other change to the requirements of the Plans and Specifications without a timely Notice of Issue for Consideration. (b) Negotiation: When the Director receives the Notice of an Issue for Consideration conforming to Section 21.5 (a) Notice Required, the Director and the Contractor will negotiate in good faith to attempt to resolve the Issue. Any resolution will be noted in the Progress Meeting minutes or confirmed otherwise in writing by the Director. Any changes to the Plans and Specifications that affect compensation, time, quality, or other requirements of the Plans and Specifications shall be by written Change Order. 31

32 21.6 SUPERINTENDENCE BY CONTRACTOR: At the site of the work, the Contractor shall employ a superintendent or foreman who shall have full authority to act for the Contractor. It is understood that such representative shall be acceptable to the Director and shall be one who can be continued in that capacity for the particular job involved unless he/she ceases to be on the Contractor's payroll. All directions given to such representative in the Contractor's absence shall be as binding as if given to the Contractor ALTERATIONS: It is further agreed that the Director may make alterations to these Contract Documents and the work herein contemplated, or any part thereof, either before or after the commencement of the work; and that the Director may at any time, order an increase in the amount of work. Such increase shall be paid for according to the quantity actually done as extra work as provided for in Section 22.4 Extra Work. If such alterations diminish the quantity of work to be done, they shall not constitute a claim by the Contractor for damages or for anticipated profits on the work dispensed with and payment will be reduced in an amount determined as provided for in Section 22.5 Reduction of Work NO CITY EMPLOYEE TO BE INTERESTED: It is further agreed that this Contract shall be utterly void as to the City if any person employed in any capacity by Lewiston is either directly or indirectly interested therein, except as provided by the City Charter WAIVER: No order by the Director or any of his/her employees, nor any order, measurement or certificate by the Director, nor any order by them for the payment of money, nor any payment for, or acceptance of, the whole or any part of the work by the Director, nor any extension of time, nor any possession taken by the Director or his/her employees, shall operate as a waiver of any provision of this Contract, or of any power herein reserved by the Director, or of any right to damages herein provided; nor shall any waiver of any breach of this Contract be held to be a waiver of any other or subsequent breach. Any remedy provided in this Contract shall be taken and construed as cumulative, that is, in addition to each and every other remedy herein provided and the City and its Director shall also be entitled to a writ of injunction against any breach of any of the promises of this Contract ACCESS TO WORK: The Director and/or his/her designee, their assistants and inspectors may, for any purpose, enter upon the work and premises used by the Contractor, and the Contractor shall provide safe and proper facilities therefore. Other City contractors may also, for all the purposes which may be required by their contracts, enter upon the work and premises used by the Contractor. Any difference or conflicts which may arise between the Contractor and other 32

33 contractors of the City in regard to their work shall be adjusted and determined by the Director DIRECTOR TO DETERMINE AMOUNT AND QUANTITY OF WORK, INSPECTION OF MATERIALS: To prevent all disputes and litigations, it is hereby agreed by and between the parties to this Contract that the Director shall in all cases determine the amount and quality of the various classes of work which are to be paid for under this Contract; and that the Director by himself/herself, or his/her representative acting under him/her, shall inspect all the materials to be furnished and all work to be done under this Contract to see that the same corresponds to the Specifications herein set forth. The Contractor further agrees that he/she will furnish the Director with such information and vouchers relating to the work, the materials therefore, and the persons employed thereon, as he/she shall from time to time request, and will give to the Director or his/her representative all necessary labor, tools and facilities for inspecting the material to be furnished and the work to be done under this Contract. The Director has the authority to stop the work whenever such a stoppage may be necessary to insure proper execution of this Contract. He/She also has the authority to reject all work and materials which do not conform to the Specifications or Plans, to direct application of forces to any portion of the work and to order the force increased or diminished as in his/her judgment is required DEFECTIVE WORK AND MATERIALS: The inspection of the work shall not relieve the Contractor of any of his/her obligations to fulfill this Contract as herein prescribed and defective work shall be made good and unsuitable materials may be rejected, notwithstanding that such work and materials have been previously overlooked by the Director and accepted or estimated for payment. If the work or any part thereof shall be found defective at any time before the final acceptance of the whole work, the Contractor shall forthwith make good such defect, in a manner satisfactory to the Director, and if any materials brought to the City for use in the work, or selected for the same, shall be rejected by the Director as unsuitable or not in conformity with the Specifications, the Contractor shall forthwith remove such materials from the vicinity of the work NO INTOXICATING DRINKS: The Contractor shall neither permit or suffer the introduction or use of intoxicating substances upon or about the works embraced in this Contract or upon any grounds occupied by him/her EXTRA WORK: The City, as applicable, reserves the right to add portions of the work required under this Contract, using the unit prices established in the proposal. The City will determine if all work 33

34 outlined in these contract Documents or portions thereof shall be implemented under this Contract prior to the Contact signing. The form Extra Work as used herein refers to and includes work required by the City which, in the judgment of the Director, involves changes in or additions to that are required by the Plans and Specifications; provided, however, such changes or additions do not result from the fault of the Contractor. The Contractor shall do any extra work when and as ordered in writing by the Director or his/her agents specially authorized thereto in writing, and shall, when requested by the Director to do so, furnish itemized statements of cost of the extra work ordered and give the Director access to the accounts, bills and vouchers relating thereto. If the Contractor claims compensation for extra work not ordered as aforesaid, or for any damage sustained, he/she shall, within one week after the beginning of any such work or of the sustaining of any such damage, make a written statement to the Directors of the nature of the work performed or damage sustained and shall, on or before the fifteenth (15th) day of the month succeeding that in which any such extra work shall have been done or any such damage sustained, file with the Director an itemized statement of the details and amount of such work or damage; and unless such statements shall be made as so required, his/her claim for compensation shall be forfeited and invalid and he/she shall not be entitled to payment on account of such work or damage. The determination of the Director shall be final upon all questions of the amount and value of extra work. If a unit price does not exist, payment for extra work will be actual cost plus fifteen per cent (15%). No allowance will be made for overhead costs REDUCTION OF WORK: The City reserves the right to delete portions of the work required under this Contract, using the unit prices established in the proposal. The City will determine if all work outlined in the plans or portions thereof shall be implemented under this Contract prior to the Contact signing. The Contractor shall omit and not perform any portion of the work required by the Contract Documents when ordered in writing by the Director or their agents specially authorized thereto in writing. If no unit price exists, an estimate will be made by the Director and/or his/her designee. Their estimate will be final and binding. These reductions shall not constitute a claim by the Contractor for damage or for anticipated profit on the work dispensed with CONDITIONS UNDER WHICH DIRECTOR MAY COMPLETE WORK: The Contractor hereby agrees that if the work to be done under this Contract shall be abandoned or if this Contract or any part thereof shall be sublet without the previous written consent of the Director, or if the Contract or any claim thereunder shall be assigned by the Contractor otherwise than as herein specified, or at any time the Director shall be of the opinion that the work is unnecessarily or unreasonably delayed, or that the Contractor is willfully violating any of the conditions or agreements of this Contract, or is not executing the 34

35 Contract in good faith, or is not making such progress in the execution of the work as to indicate its completion within the required time, the Director shall have the power and right to notify the Contractor to discontinue all work or any part thereof under this Contract. Thereupon the Contractor shall discontinue the work or any such parts thereof as the Director shall have the power, by contract with or without advertising, day labor or otherwise as he/she may determine, to employ such labor and obtain such tools and appliances as he/she may deem necessary to work at and be used to complete the work herein described or such parts thereof as the Director may deem necessary, and to use such tools and materials of every description as may be found upon the line of work, and to procure other materials for the completion of the same, and to charge the expense of said labor, tools and materials to the Contractor; and the expense so charged shall be deducted and paid by the City out of such monies as may be due or may become due the Contractor under this Contract or any part thereof. In case such expense is more than the sum which would have been payable under this Contract, if the same had been completed by the Contractor, then the Contractor shall pay the amount owed by the City under this Contract at the time the Contractor is notified in writing to discontinue the work or any part thereof PAYMENT FOR MATERIALS: Payments will be made in accordance with the price stated in the Contract. The Contractor may include requests for payment of material provided to the City when such requests are accompanied by invoices substantiating the requests for material payment satisfactory to the City GUARANTEE: The Contractor guarantees that the work to be done under this Contract will be done in a good and workmanlike manner and all services rendered, whether furnished by him/her or sub-contractors retained by the Contractor, will be in accordance with the terms and specifications of these Contract Documents, in all respects. This guaranty will be for a period of one (1) year after the date of acceptance of the whole work by the City. If at any time within the period of the guaranty, any part of the work performed under the terms of this Contract shall in the opinion of the Director require additional work, which is outside the terms and specifications of these Contract Documents, the Director shall notify the Contractor in writing of the work required. If the Contractor shall neglect to perform the work required to the satisfaction of the Director within the time limit as set forth in the notice in writing to the Contractor, then the Director may perform the additional work necessary, by contract or otherwise, and the City shall have a claim against the Contractor in the amount of the expense incurred by the City in performing such work. It is hereby, however, specifically agreed and understood that this guaranty shall not include any modifications made necessary by any cause or causes other than defective workmanship or services rendered by the Contractor, their sub-contractors or their agents. 35

36 22.9 WORK DAY: A work day shall be any day, other than a State of Maine legal holiday or Sunday, on which weather and working conditions permit the Contractor to make effective use of not less than seventy-five (75%) per cent of the hours during the regular work day. In the event the Contractor is granted permission to engage in work on a legal holiday or Sunday, such a day will be considered and counted as a work day. 36

37 Appendix A Monitoring Sites Collection Order & Screen Depth 37

38 Table 2A Monitoring Wells Sampling Order Lewiston Sold Waste Facility Lewiston. Maine SECURE LANDFILL ATTENUATION LANDFILL Order of Sample Location Target Pump Intake: Location Target Pump Intake: Collection Pump Rate depth below Pump Rate depth below (ml/min) GROUND (ml/min) GROUND SURFACE SURFACE (feet) (feet) Upgradient Locations MW MW MW MW MW Crossgradient MW MW Locations MW MW-205A* MW MW-205B* MW MW MW MW MW Downgradient MW MW-207* ** ~50 Locations M-303B* M-303C* LDS/Surface Water MH-6U SW-1 Locations MH-6L SW-2 LD-1 SW-3 LD-2 MH-14 NOTES: 1. The recommended sample order should be followed during each sampling event. The target pump rates are based on flow rates (field data) collected from the preceding three years. 2. Recently, monitoring wells M-303B and M-303C have not been sampled as part of routine groundwater monitoring at the Lewiston Solid Waste Facility; therefore, target pump rate information is unavailable. * indicates that the static water level in the specified monitoring locations consistently requires the use of a submersible pump. "**" indicates that the specified monitoring location may have insufficient recharge to support low-flow sampling techniques with a submersible pump; furthermore, the head differential in the static water level is greater than 30 feet thus eliminating the potential for using a peristaltic pump. As mentioned in the text of the EMP, groundwater samples will be collected from this location for Detection Monitoring Parameter analysis as part of the tri-annual monitoring and reporting. Future evaluation will be made regarding (1) whether or not this location provides representative information pertaining to the other locations in the sample group; and (2) the possible replacement of this monitoring location with a new well. Lewiston Solid Waste Facility Environmental Management Plan REGISTERED COPY No. 01 Revised 12/21/99 Table of Contents

39 , B-302 Date started: Total depth: 240' ' ' 52' 63-80' ' 100' 128' 137' ' 215' ' 240' Date completed: Ground elevation: ' Soil overburden. Approximately 1' of sludge or sludge saturated soil was penetrated. Dark gray to black hornblende/biotite schist. Soft zone, rapid penetration, no water. White gray muscovite rich quartz biotite gneiss{?). Rock becoming changing to purple gray mica schist. Considerably softer. Soft zone, possible fractures. Rapid penetration, soft zone, no water yield. Soft possibly fractured zone, no flow., Change to light gray muscovite biotite quartz schist. Soft zone, no appreciable flow. Gray granite to granodiorite in composition. Hole terminated. Final yield = 0.25 gpm. Well Installation Date: B-302 A Screen depth : 118.6' ' Type: 2 inch PVC Sealed zone: 117'-138.6' Stickup: 2.2' B-302 B Screen depth: 200'-225' Type: 2 inch PVC Sealed zone: 198'-245' Stickup: 2.2' B-303 Date started: Date completed: Total depth: 240' Ground elevation: ' SoiJ overburden. Silty sand above sandy gravel. 9-40' 40-65' 65-75' ' Light gray biotite muscovite quartz schist with alternating with black hornblende{?} biotite rich zones. Alternating differentia ted zones of 1 ight green augite or serpentine quartz gneiss{?} and black hornblende biotite rich layers. Soft micaceous schist. Light gray to white garnet orthoclase schist(?).

40 ' ' ' ' Black biotite hornblende rich zone. Soft possibly fractured zone. Yield < lgpm. Purple gray biotite muscovite quartz schist. 170' Soft zone. No weathering or other evidence of fractures. No significant water yield ' Harder light gray quartz feldspar rock. Granite-gneiss in composition ' 240' Gray-green augite biotite quartz schist. Hole terminated at 240'. Yield<.1 gpm. Well Installation Date: A Screen depth: 65' - 85' Type: 2 inch PVC Sealed zone: 60'- '90' Stickup: 1.5' Screen depth: 135'- 155' Type: 2 inch PVC Sealed zone: 130.8'-159' Stickup: 1.5' c Screen depth: 240'-260' Type: 1. 5 inch PVC Sealed zone: 220'-260' Stickup: 1.5'

41 TABLE 1 Monitoring Well Summary Data Well Location Well Type Elevation at ground level (MSL) Elevation at top of PVC (MSL) Elevation of Screened Interval Length of Screen ( ftl MW-201 Bedrock MVl-202 Overburden MW-203 Overburden MW-204 Overburden MW-205A Overburden MW-2058 Bedrock MN-206 Overburden,..._ MW-207 Overburden MW-101 Overburden '-' ' MW-103 Overburden

42 WELL NUMBER GROUND ELEV. (2) TOTAL BORING DEPTH (3) WELL DEPTH SCREEN ELEVATION (from to) DEPTH TO ROCK SEAL RANGE (from to) MW [cm/sec] E E-04 MW E E-05 MW E E-04 MW E E-04 MW E E-05 MW E E-04 MW E E-04 MW E E-04 MW E E-03 MW E E-06 MW E E-04 MW E E-05 (1)All wells are constructed from 2" PVC. (2)All elevations in feet with MSL datum from Woodard and Curran survey. (3)All depth values in feet from ground surface. (4)Analysis Method: H. Bower and R.C. Rice (1976) WELL CONSTRUCTION and HYDRAULIC CONDUCTIVITY DATA WATER ELEV. CONDUCTIVITY (4) 11/16/90 [ft/sec] As part of the construction of Phase III of the secure landfill, on December 16, 2008, Northern Test Boring, located in Gorham, ME., extended the length of MW-7 & MW-8, 5 feet. The current well depths are - MW and MW

43 Appendix B Monitoring Points - Sample Parameters 38

44 Table 1 Detection Monitoring Program Lewiston Solid Waste Facility - Lewiston, Maine DMPs for Secure Landfill Attenuation Landfill Detection Monitoring Program Detection Monitoring Leachate Monitoring Detection Monitoring Surface Water Monitoring Landfill Parameters: BOD X X X X COD X X X X TDS X X X X TSS X X X X TOC X X X X VOCs X Phenols X X Major Cations/Anions: Alkalinity X X X X Ammonia (NH 3 -N) X X X X Bicarbonate (HCO 3 ) X X X X Calcium X X X X Chloride X X X X Magnesium X X X X Nitrate X X X X Potassium X X X X Sodium X X X X Sulfate X X X X Metals: Aluminum X X X X Arsenic X X X X Barium X X Cadmium X X X X Chromium X X X X Iron X X X X Lead X X X X Manganese X X X X Nickel X X Selenium X X Silver X X Vanadium X X Lewiston Solid Waste Facility Environmental Management Plan REGISTERED COPY No. 01 Revised 12/21/99 Table of Contents

45 Table 1 Detection Monitoring Program Lewiston Solid Waste Facility - Lewiston, Maine NOTES: 1. Italicized parameters indicate that analysis of the specified parameter that is required under Chapter 405 (Column 1 Detection Parameters in Appendix A). Emboldened italicized parameters are required under Chapter 405 and may not be omitted from analytical testing. 2. Additional parameters in normal font were included due to periodic detections during site characterization monitoring (i.e., Baseline Monitoring or Comprehensive Monitoring) or due to the inherent nature of the wastes contained in each area respectively. a. For example, VOCs and phenolic compounds were included as monitoring parameters for the Attenuation Landfill due to the organic nature of the wastes and the absence of a liner in this area. VOC sampling & analysis have been discontinued from MW-101, MW-103, MW-205A, MW-205B, SW-1, SW-2 & SW-3 per DEP recommendation, dated July 12, In the Secure Landfill, however, ash typically contains little or no organic matter, and leachate from the Phase I cell has not shown significant levels of VOC or SVOC contamination, despite numerous analyses for these constituents. Therefore, a recommendation for a "full scan" analysis of groundwater for 40 CFR Part 258, Appendix I organic parameters is not warranted at this time. b. Also, a more comprehensive list of metals are included in the monitoring parameters for the Secure Landfill as a result of ash leachate characterization studies performed in Collection of field parameter data via low-flow sampling is also required under Chapter 405 (Column 1 Detection Parameters in Appendix A) and is addressed in the Sampling, Handling and Analysis of Groundwater sections of the document text. 4. Methods for performing the corresponding laboratory analyses are specified in Table The order for which the samples are collected is summarized in Tables 2 and 2a. 6. In addition to the parameters listed in Table 1, the Attenuation Landfill shall be monitored annually for the Column 2 parameters as required by Chapter 405 2(C)2(e). These parameters include the Column 1 parameters listed above in Table 1 and also the following: Eh, cyanide, antimony, barium, beryllium, cobalt, copper, nickel, selenium, silver, thallium, vanadium, and zinc. Lewiston Solid Waste Facility Environmental Management Plan REGISTERED COPY No. 01 Revised 12/21/99 Table of Contents

46 Table 2B Sample Collection Order Lewiston Solid Waste Facility- Lewiston. Maine Order of Sample Analytical MEG MCL 2 Collection Method 1 (µg/l) (µg/l) SECURE LANDFILL AND LEACHATE MONITORING PARAMETERS Landfill Parameters: VOCs 4 NA TOC EPA TOX NA MDL 3 (µg/l) Alkalinity Ca-Mg Hardness 2350B SMEWW Coliform Bacteria 9222B SMEWW TDS EPA 500,000 TSS EPA BOD EPA COD EPA Metals: Aluminum EPA Arsenic EPA Barium EPA Cadmium EPA Chromium EPA Iron EPA 300 Lead EPA Manganese EPA Mercury 7470 SW Molybdenum EPA Nickel EPA Selenium EPA Silver EPA Vanadium EPA Nutrients/Anions: Bicarbonate 4500-CO2 SMEWW Chloride EPA 250,000 Nitrate EPA 10,000 10,000 5,000 Phosphorus EPA Sulfate 4500-SO4E SMEWW 250,000 Cations: Ammonia EPA Calcium EPA Magnesium EPA Potassium EPA Sodium EPA Lewiston Solid Waste Facility Environmental Management Plan REGISTERED COPY No. 01 Revised 12/21/99 Table of Contents

47 Table 2B Sample Collection Order Lewiston Sold Waste Facility - Lewiston, Maine Order of Sample Collection Analytical Methods MEG (µg/l) MCL 2 (µg/l) MDL 3 (µg/l) ATTENUATION LANDFILL AND SURFACE WATER MONITORING PARAMETERS Landfill Parameters: VOCs A SW-846 TOC EPA TOX NA Alkalinity Ca-Mg Hardness 2350B SMEWW Coliform Bacteria 9222B SMEWW TDS EPA 500,000 TSS EPA BOD EPA COD EPA Phenols A SW-846 Metals: Aluminum EPA Arsenic EPA Barium EPA Cadmium EPA Chromium EPA Iron EPA 300 Lead EPA Manganese EPA Nutrients/Anions: Bicarbonate 4500-CO2 SMEWW Chloride EPA 250,000 Nitrate EPA 10,000 10,000 5,000 Sulfate 4500-SO4E SMEWW 250,000 Ammonia EPA Cations: Calcium EPA Magnesium EPA Potassium EPA.Sodium EPA Lewiston Solid Waste Facility Environmental Management Plan REGISTERED COPY 01 Revised 12/21/99 Table of Contents

48 Table 2B Sample Collection Order Lewiston Sold Waste Facility Lewiston, Maine NOTES: 1. Analytical laboratory methods listed are taken from the following sources: SW-846: Test Methods for Evaluating Solid Waste, U.S. Environmental Protection Agency, 3rd Edition (Revision 4), Washington, D.C., 1997 SMEWW: American Public Health Association, 1992 Standard Methods for the Examination of Water and Wastewater, 18th Edition, Boston, 1992 EPA: Methods for Chemical Analysis of Water and Waste, U.S. Environmental Protection Agency, Washington, D.C., MCLs (Maximum Contaminant Levels) established by EPA (updated 1996) have been included; Secondary MCLs or Action Levels (i.e., lead) have been indicated in italics. No entry indicates that no MCL or MEG (Maximum Exposure Guideline) have been established. 3. As stated in Maine Solid Waste Management Regulations, MDLs (Minimum Detection Limits) must be at least one-half the corresponding MCL/MEG, whichever is more stringent. These values are listed where applicable. 4. The volatile organics to be analyzed are those listed in Method 8240, Table 1 of Test Methods for Evaluating Solid Wastes, USEPA SW-846. It should be noted that the MDLs for each individual constituent will be at least one-half the corresponding MCL/MEG. 5. The phenolic compounds to be analyzed are those listed in Method 625, Table 2 of 40 CFR Part 136 Appendix A. Lewiston Solid Waste Facility Environmental Management Plan REGISTERED COPY No. 01 Revised 12/21/99 Table of Contents

49 Field Parameters TABLE 2B SAMPLE COLLECTION ORDER Secure Landfill Attenuation SW-846 Standard EPA Water Preservation Sample Holding MCL MEG and Leachate/ Landfill and Methods 7 Methods 7 & Waste 7 Method Bottles Time (days) (ug/l) (ug/l) Leak Detection Surface Water Monitoring Groundwater Elevation ) X X Flow Rate 2 X X Conductivity X X ph X X Dissolved Oxygen 2 X X Field Observations 3 X X Landfill Parameters Volatile Organics drops 1:1 HCI 40 ml VOA 14 X 6 TOC H 2SO 4 ph<2 Plastic or Glass 28 X X TOX (Total Organic Halides) 9020B 4 C Glass 28 X Alkalinity 4 C Plastic 14 TDS C Plastic 7 X TSS C Plastic 7 X BOD C Plastic 2 X X 2 COD H 2SO 4 ph<2 Plastic 28 X X Phenols A 4 C Amber glass 7 X 6 Metals Aluminum (Al) HNO 3 ph<2 Plastic X Arsenic (As) HNO 3 ph<2 Plastic X X Barium (Ba) HNO 3 ph<2 Plastic X Cadmium (Cd) HNO 3 ph<2 Plastic X X Chromium (Cr) HNO 3 ph<2 Plastic X X Iron (Fe) HNO 3 ph<2 Plastic X X Lead (Pb) HNO 3 ph<2 Plastic X X Manganese (Mn) HNO 3 ph<2 Plastic X X Nickel (Ni) HNO 3 ph<2 Plastic X Selenium (Se) HNO 3 ph<2 Plastic X Silver (Ag) HNO 3 ph<2 Plastic X Vanadium HNO 3 ph<2 Plastic 180 X Monitoring p /Lewiston/ /Table2 xls Page 1 of 2 Environmental Monitoring Plan

50 TABLE 2B SAMPLE COLLECTION ORDER Lewiston Solid Waste Facility - Lewiston Secure Landfill Attenuation SW-846 Standard EPA Water Preservation Sample Holding MCL MEG and Leachate/ Landfill and Methods 7 Methods 7 & Waste 7 Method Bottles Time (days) (ug/l) (ug/l) Leak Detection Surface Water Monitoring Monitoring Nutrients/Anions Bicarbonate (HCO 3) C Plastic 14 X X Chloride (CI) C Plastic ,000 X X Nitrate (NO 3) C Plastic 2 10,000 10,000 X X Sulfate (SO 4) _ 4500-SO4E 4 C Plastic X X Ammonia-Nitrogen (NH 3N) H 2SO 4 ph<2 Plastic 28 X Cations Calcium (Ca) HNO 3 ph<2 Plastic 180 X X Magnesium (Mg) HNO 3 ph<2 Plastic 180 X X Potassium (K) HNO 3 ph<2 Plastic 180 X X Sodium (Na) _ HNO 3 ph<2 Plastic 180 X X 1 The water level in each well shall be determined immediately prior to purging the well for sampling. 2 Surface water samples only. 3 Any unusual conditions (colors, odors, surface sheens, precipitates, etc.) noticed during well purging or sampling must be recorded in a field logbook and reported to the DEP with the monitoring results. Dissolved oxygen, turbidity, and drawdown & pumping rate will be recorded at the time of sampling. 4 The volatile organics to be analyzed are those listed in Method 8240, Table 1 of Test Methods for Evaluating Solid Wastes. U.S. EPA SW The phenolic compounds to be analyzed are those listed in Method 625, Table 2 of 40 CFR Part 136 Appendix A. 6 Groundwater only, not surface water. 7 References: SW-846: Test Methods for Evaluating Solid Waste, U.S. Environmental Protection Agency, 3rd Edition (Revision 4), Washington, D.C., 1997 American Public Health Association, 1992 Standard Methods for the Examination of Water and Wastewater, 18th Edition, Boston, 1992 Methods for Chemical Analysis of Water and Waste, U.S. Environmental Protection Agency, Washington, D.C., 1983 p /Lewiston/ /Table2 xls Page 2 of 2 Environmental Monitoring Plan

51 Appendix C EPA Guidelines Low Flow Procedures 39

52 7 United States Environmental Protection Agency Office of Research and Development Office of Solid Waste and Emergency Response EP A/540/5-95/504 &EPA Ground Water Issue LOW-FLOW (MINIMAL DRAWDOWN) GROUND-WATER SAMPLING PROCEDURES by Robert W. Puls 1 and Michael J. Barcelona 2 Background The Regional Superfund Ground Water Forum is a group of ground-water scientists, representing EPA's Regional Superfund Offices. organized to exchange information related to ground-water remediation at Superfund sites. One of the major concerns of the Forum is the sampling of ground water to support site assessment and remedial performance monitoring objectives. This paper is intended to provide background information on the development of low-flow sampling procedures and its application under a variety of hydrogeologic settings. It is hoped that the paper will support the production of standard operating procedures for use by EPA regional personnel and other environmental professionals engaged in ground-water sampling. For furlher information contact: Robert Puis, , Subsurface Remediation and Protection Division, NRMRL, Ada, OK. I. Introduction The methods and objectives of ground-water sampling to assess water quality have evolved over time. Initially the emphasis was on the assessment of water quality of aquifers as sources of drinking water. Large water-bearing units were identified and sampled in keeping with that objective. These were highly productive aquifers that supplied drinking water via private wells or through public water supply systems. Gradually, with the increasing awareness of subsurface pollution of these water resources, the understanding of complex hydrogeochemical processes which govern the fate and transport of contaminants in the subsurface increased. This increase in understanding was also due to advances in a number of scientific disciplines and improvements in tools used for site characterization and ground-water sampling. Ground-water quality investigations where pollution was detected, initially borrowed ideas, methods, and materials for site characterization from the water supply field and water analysis from public health practices. This included the materials and manner in which monitoring wells were installed and the way in which water was brought to the surface, treated, preserved and analyzed. The prevailing conceptual ideas included convenient generalizations of ground-water resources in terms of l~rge and relatively homogeneous hydrologic yunits". With time it became apparent that conventional water supply generalizations of "homogeneity" did not adequately represent field data regarding pollution of these subsurface resources. The important role of "heterogeneity" became increasingly clear not only in geologic terms, but also in terms of complex 'NIItloMI Risk Man gement ResMirch Labo,.tory, U.S. EPA 1 UnlvetSity of Allch;g.n Superfund Technology Support Center for Ground Water National Risk Management Research Laboratory Subsurface Protection itnd Remediation Division Robert S. Kerr Environmental Research Center Ada, Oklahoma

53 physical, chemical and biological subsurface processes. Wrth greater appreciation of the role of heterogeneity, it became evident that subsurface pollution was ubiquitous and encompassed the unsaturated zone to the deep subsurface and included unconsolidated sediments, fractured rock, and aquitards" or low-yielding or impermeable formations. Smallscale processes and heterogeneities were shown to be important in identifying contaminant distributions and in controlling water and contaminant flow paths. It is beyond the scope of this paper to summarize all the advances in the field of ground-water quality investigations and remediation, but two particular issues have bearing on ground-water sampling today: aquifer heterogeneity and colloidal transport. Aquifer heterogeneities affect oontaminant flow paths and include variations in geology, geochemistry, hydrology and microbiology. As methods and the tools available for subsurface investigations have become increasingly sophisticated and understanding of the subsurface environment has advanced, there is an awareness that in most cases a primary concern for site investigations is characterization of contaminant flow paths rather than entire aquifers. In fact, in many cases, plume thickness can be less than well screen lengths (e.g. 3-6m) typically installed at hazardous waste sites to detect and monitor plume movement over time. Small-scale differences have increasingly been shown to be important and there is a general trend toward smaller diameter w.ells and shorter screens. The hydrogeochemical significance of collpidal-size particles in subsurface systems has been realized during the past several years (Gschwend and Reynolds. 1987; McCarthy and Zachara, 1989; Puis, 1990; Ryan and Gschwend, 1990). This realization resulted from both field and laboratory studies that showed faster contaminant migration over greater distances and at higher concentrations than flow and transport model predictions would suggest (Buddemeier and Hunt, 1988; Enfield and Bengtsson, 1988; Penrose et al. 1990). Such models typically account for interaction between the mobile aqueous and immobile solid phases, but do not allow for a mobile, reactive solid phase. It is recognition of this third "phase" as a possible means of contaminant transport that has brought increasing attention to the manner in which samples are collected and processed for analysis (Puis et al. 1990; McCarthy and Degueldre, 1993; Backhus et al. 1993; USEPA 1995). If such a phase is present in sufficient mass, possesses high sorption reactivity, large surface area. and remains stable in suspension, it can serve as an important mechanism to facilitate contaminant transport in many types of. subsurface systems. Colloids are particles that are sufficiently small that the surface tree energy of the particle dominates the bulk free energy. Typically, in ground water. this includes particles with diameters between 1 and 1000 nm. The most commonly observed mobile particles include: secondary clay minerals; hydrous iron, aluminum. and manganese oxides; dissolved and particulate organic materials, and viruses and bacteria. These reactive particles have been shown to be mobile under a variety of conditions in both field studies and laboratory column experiments, and as such need to be included in monitoring programs where identification onhe "total" mobiie contaminant loading (dissolved + naturally suspended particles) at a site is an objective. To that end, sampling methodologies must be used which do not artificially bias naturally" suspended particle concentrations. Currently the most common ground-water purging and sampling methodology is to purge a well using bailers or high speed pumps to remove 3 to 5 casing volumes followed by sample collection. This method can cause adverse impacts on sample quality through collection of samples with high levels of turbidity. This results in the inclusion of otherwise immobile artifactual particles which produce an overestimation of certain analytes of interest (e.g. metals or hydrophobic orgariic compounds). Numerous documented problems associated with filtration (Danielsson, 1982; laxen and Chandler, 1982; Horowitz et al. 1992) make this an undesirable method of rectifying the turbidity problem, and include the removal of potentially mobile (contaminantassociated),particles during filtration, thus artificially biasing contaminant concentrations low. Sampling-induced turbidity problems can often be mitigated by using low-flow purging and sampling techniques. Current subsurface conceptual models have undergone considerable refinement due to the recent development and increased use of field screening tools. Socalled hydraulic ~push~ technologies (e.g. cone penetrometer, Geoprobe, QED HydroPunch ) enable relatively fast screening site characterization which can then be used to design and install a monitoring well network. Indeed. alternatives to conventional monitoring wells are now being considered for some hydrogeologic settings. The ultimate design of any monitoring system should however be based upon adequate site charac;terization and be consistent with established monitoring objectives.. If the sampling program objectives include accurate assessment of the magnitude and extent of subsurface contamination over lime and/or accurate assessment of subsequent remedial performance then some information regarding plume delineation in three dimensional space is necessary prior to monitoring well network design and inst~llation. This can be accomplished with a variety of different tools and equipment ranging from hand-operated augers to screening tools mentioned above and large drilling rigs. Detailed information on groundwater flow velocity, direction. and horizontal and vertical variability are essential baseline data requirements. Detailed soil and geologic data are required prior to and during the installation of sampling points. This includes historical as well as detailed soil and geologic logs which accumulate during the site investigation. 2

54 The use of borehole geophysical techniques.are also recommended. With this information (together with other site characterization data) and a clear understanding of sampling objectives, then appropriate location, screen length, well diameter. slot size etc. for the monitoring well network can be decided. This is especially critical for new in situ remedial approaches or natural attenuation assessments at hazardous waste sites. In general, the overall goal of any ground-water sampling program is to collect water samples with no alteration in water chemistry; analytical data tl:lus obtained may be used for a variety of specific monitoring programs depending on the regulatory requirements. The sampling methodology described in this paper assumes that the monitoring goal is to sample monitoring wells for the presence of contaminants and it is applicable whether mobile colloids are a concern or not and whether the analytes of concern are metals (and metalloids) or organic compounds. II. Monitoring Objectives and Design Considerations. The following issues are important to consider prior to the design and implementation of any ground-water monitoring program, including those which anticipate using low-flow purging and sampling procedures. A. Data Quality Objectives (OQO's) Monitoring objectives include four main types: detection, assessment, corrective-action evaluation and resource evaluation, along with "hybrid" variations such as site-assessments for property transfers and water availability investigations. Monitoring objectives may change as contamination or water quality problems are discovered. However, there are a number of common components of monitoring programs which should be recognized as important regardless of initial objectives. These components include: 1) Development of a conceptual model that incoiporates elements of the regional geology to the local geologic framework. The conceptual model development also includes initial site characterization efforts to identify hydrostratigraphic units and likely flow-paths using a minimum number of borings and well completions; 2) Cost-effective and well doetjmented cqllection of high quality data utilizing simple, accurate, and reproducible techniques; and 3) Refinement of the conceptual model based on supplementary da~ collection and analysis. These fundamental components serve many types of monitoring programs and provide a basis for future efforts that evolver in complexity and level of spatial detail as purposes and objectives expand. High quality, reproducible data collection is a common goal regardless of program objective. High quality data collection implies data of. sufficient accuracy, precision, and completeness (i.e. ratio of valid analytical results to the minimum sample number called for by the program design) to meet the program objectives. Accuracy depends on the correct choice of monitoring tools and procedures to minimize sample and subsurface disturbance from collection to analysis. Precision depends on the repeatability of sampling and analytical protocols. It can be assured or improved by replication of sample analyses including blanks, field/lab standards and reference standards. B. Sample Representativeness An important goal of any monitoring program is collection of data that is truly representative of conditions at the site. The term representativeness applies to chemical and hydrogeologic data collected via wells, borings. piezometers, geophysical and soil gas measurements, lysimeters, and temporary sampling points. It involves a recognition of the statistical variability of individual subsurface physical properties. and contaminant or major ion concentration-levels, while explaining extreme values. Subsurface temporal and spatial variability are facts. Good professional practice seeks to maximize representativeness by using proven accurate and reproducible techniques to define limits on the distribution of measurements collected at a site. However, measures of representativeness are dynamic and are controlled by evolving site characterization and monitoring objectives. An evolutionary site characterization model, as shown in Figure 1, provides a systematic approach to the goal of consistent data collection.,. _..Define Program Obj~- ~ Eatal>hh ~ Qlallty _. o.fine Sjpling and Evolutlo,..ry Sho Analytieal Protocola Cha...,_lon... Ref'- ' Applr Protoco Ia ' Protocola +- _ F.gure 1. Evolutionary Site Characterization Model The model emphasizes a recognition of the causes of the variability (e.g. use of inappropriate technology such as using bailers to purge wells; imprecise or operator dependent methods) and the need to control avoidable errors. 3

55 1) Questions of scale A sampling plan designed to collect representative samples must take into acx:ount the potential scale of changes in site conditions through space and time as well as the chemical associations and behavior of the parameters that are targeted for investigation. In subsurface systems, physical (i.e. aquifer) and chemical properties over time or space are not statistically independent. In fact samples taken in close proximity (i.e. within distances of a few yards) or within short time periods (i.e. more frequently than monthly) are highly auto-correlated. This means that designs employing high-sampling frequency (e.g. monthly) or dense spatial monitoring designs run the risk of redundant data collection and misleading inferences regarding trends in values that aren't statistically valid. In practice, contaminant detection and assessment monitoring programs rarely suffer these over-sampling concerns. In corrective-action evaluation programs. it is also possible that too little data may be collected over space or time. In these cases, false interpretation o! the spatial extent of contamination or underestimation of temporal concentration variability may result. 2) Target Parameters Parameter selection in monitoring program design is most often dictated by the regulatory status of the site. However, background water quality constituents,.purging indicator parameters, and contaminants, all represent targets for data collection programs. The tools and procedures used in these programs should be equally rigorous and applicable to all categories of data. since all may be needed to determine or support regulatory action. C. Sampling Point Design and Construction Detailed site characterization is central to all decision-making purposes and the basis for this characterization resides in identification of the geologic framework and major hydro-stratigraphic units. Fundamental data for sample poi,nt location include: subsurface lithology, head-differences and background geochemical conditions. Each sampling point has a proper use or uses which should be documented at a level which is appropriate for the program's data quality objectives. Individual sampling points may not always be able to fulfill multiple monitoring objectives (e.g. detection, assessment, corrective action). 1) Compatibility with Monitoring Program and Data Quality Objectives Specifics of sampling point location and design will be dictated by the complexity of subsurface lithology. and variability in contaminant and/or geochemical conditions. It should be noted that. regardless of the ground-water sampling approach. few sampling points (e.g. wells, drivepoints, screened augers) have zones of influence in excess of a few feet. Therefore the spatial frequency of sampling points should be carefully selected and designed. 2) Flexibility of Sampling Point Design In most cases "well-point" diameters in excess of 1 7/8 inches will permit the use of most types of submersible pumping devices for low-flow (minimal drawdown) sampling. It is suggested that "short" (e.g. less than 1.6 m) screens be incorporated into the monitoring design where possible so that we might expect comparable results from one device to another. "Short", of course, is relative to the degree of vertical water quality variability expected at a site. 3) Equilibration of Sampling Point Time should be allowed for equilibration of the well or sampling point with the formation after installation. Placement of well.or sampling points in the subsurface produces some disturbance of ambient conditions. Drilling techniques (e.g. auger, rotary, etc.) are generally considered to cause more disturbance than direct-push" technologies. In either case, there may be a period (i.e. days to months) during which water quality near the point may be distint:tly different from that in the formation. Proper development of the sampling point and adjacent formation to remove fines created during emplacement will shorten this water quality recovery period. Ill. Definition of Low-Flow Purging and Sampling It is generally accepted that water in the well casing is non-representative of the formation water and needs to be purged prior to collection of ground-water samples. However, the water in the screened interval may indeed be representative of the formation, depending upon well construction and site hydrogeology.. Wells are purged to some extent for the following reasons: the presence of the air interface at the top of the water column resulting in an oxygen concentration gradient with depth, loss of volatiles up the water column, leaching from or sorption to the casing or filter pack, chemical changes due to clay seals or backfill, and surface infiltration. Low-flow purging, whether using portable or dedicated systems, should be done using pump-intake located in the middle or slightly above the middle of the screened interval. Placement of the pump too close to the bottom of the well will cause increased entrainment of solids which have collected in the well over time. These particles are present as a result of well development, prior purging and sampling events, and natural colloidal transport and deposition. Therefore, placement of the pump in the middle or toward the top of the screened interval is suggested. Placement of the pump at the top of the water column for sampling is only recommended in unconfined aquifers, screened across the water table, where this is the desired 4

56 sampling point. Low-flow purging has the aqvantage of mi:1imizing mixing between the overlying stagnant casing water and water within the screened interval A. Low-Flow Purging & Sampling Low-flow refers to the velocity with which water enters the pump intake and that is imparted to the formation pore water in the immediate vicinity of the well screen. It does not necessarily refer to the flow rate of water discharged at the surface which <'.an be affected by flow regulators or restrictions. Water level drawdown provides the best indication of the stress imparted by a given flow-rate for a given hydrological situation. The objective is to pump in a manner that minimizes stress (drawdown) to the system to the extent practical taking into account established site sampling objectives. Typically flow rates on the order of Umin are used, however this is dependent on site-specific hydrogeology. Some extremely coarse-textured formations have been successfully sampled in this manner at flow rates to 1 Umin. The effectiveness of using low-flow purging is intimately linked with proper screen location, screen length, and well construction and development techniques. The reestablishment of natural flow paths in both the vertical and horizontal directions are important for correct interpretation of the data. For high resolution sampling needs, screens less than 1 m should be used. Most of the need for purging has.been found to be due to passing the sampling device through the overlying casing water which causes mixing of these stagnant waters and the dynamic waters within the screened interval. Additionally, there is disturbance to suspended sediment collected in the bottom of the casing and the displacement of water out into the formation immediately adjacent to the well screen. These disturbances and impacts can be avoided using dedicated sampling equipment, which precludes the need to insert the sampling device prior to purging and sampling. Isolation of the screened interval water from the overlying stagnant casing water may be accomplished using low-flow minimal drawdown techniques. If the pump intake is located within the screened interval most of the water pumped will be drawn in directly from the formation with little mixing of casing water or disturbance to the sampling zone. However, if the wells are not constructed and developed properly, zones other than those intended may be sampled. At some sites where geologic heterogeneities are sufficiently different within the screened interval, higher conductivity zones may be preferentially sampled. This is another reason to use shorter screened intervals, especially where high spatial resolution is a sampling objective. B. Water Quality Indicator Parameters It is recommended that water quality indicator parameters be used to determine purging needs prior to sample collection in each well. Stabilization of parameters such as ph, specific conductance, dissolved oxygen, oxidation-reduction potential, temperature and turbidity should be used to determine when formation water is accessed during purging. In general the order of stabilization is ph, temperature, and specific conductance. followed by oxidationreduction potential, dissolved oxygen and turbidity. Temperature and ph, while commonly used as purging indicators, are actually quite insensitive in distinguishing between formation water and stagnant casing water; nevertheless, these are important parameters for data interpretation purposes and should also be measured. Performance criteria for determination of stabilization should be based on water-level drawdown, pumping rate and equipment specifications for measuring indicator parameters. Instruments are available which utilize in-line flow cells to continuo Jsly measure the above parameters. It is important to establish specific well stabilization criteria and then consistently follow the same methods thereafter, particularly with respect to drawdown, flow rate and sampling device. Generally the time or purge volume required for parameter stabilization is independent of well depth or well volumes. Dependent variables are well diameter, sampling device, hydrogeochemistry; pump flow rate, and whether the devices are used in a portable or dedicated manner. If the sampling device is already in place (ie, dedicated sampling systems), then the time and purge volume needed for stabilization is much shorter. Other advantages of dedicated equipment include less purge water for waste disposal, much less decontamination of equipment. less time spent in preparation of sampling as well as time in the field, and more consistency in the sampling approach which probably will translate into less variability in sampling results. The use of dedicated equipment is strongly recommended at wells which will undergo routine sampling over time. If parameter stabilization criteria are too stringent, then minor oscillations in indicator parameters may cause purging operations to become unnecessarily protracted. It should also be noted that turbidity is a very conservative parameter in terms of stabilization. Turbidity is always the last parameter to stabilize. Excessive purge times are invariably related to the establishment of too stringent turbidity stabilization criteria. It should be noted that natural turbidity levels in ground water may exceed 1 0 nephelometric turbidity units (NTU). C. Advantages and Disadvantages of Low-Flow (Minimum Drawdown) Purging In general, the advantages of low-flow purging include: samples which are representative- of the 'mobile' load of contaminants present (dissolved and colloidassociated), minimal disturbance of the 'Sampling point thereby minimizing sampling artifacts. less operator variability, greater operato.r control, 5

57 reduced stress on the fonnation (minimal drawdown), less mixing of stagnant casing water with formation water, reduced need tor filtration and therefore less time required for sampling, smaller purging volume which decrease waste disposal costs and sampling time. better sample consistency; reduced artificial sample variability Some disadvantages of low-flow purging are: higher initial capital costs, greater set-up time in the field, need to transport additional equipment to and from the site, increased training needs, resistance to change on the part of sampling practitioners, concem that new data will indicate a "change in conditions and trigger an "action". IV. Low-Flow (Minimal Drawdown) Sampling Protocols The following ground water sampling procedure has evolved over many years of experience in ground water sampling for organic and inorganic compound detenninations and as such summarizes the authors (and others) experiences to date (Barcelona et al., 1984, 1994; Barcelona and Helfrich, 1986; Puis and Barcelona, 1989; Puis et. al. 1990, 1992; Puis and Powell, 1992; Puis and Paul, 1995). High-quality chemical data collection is essential in ground water monitoring and site characterization. The primary limitations to the collection of representative ground water samples include: mixing of the stagnant casing and "fresh" screen waters during insertion of the sampling device or ground water level measurement device; disturbance and resuspension of settled solids at the bottom of the well when using high pumping rates or raising and lowering a pump or bailer; introduction of atmospheric gases or degassing from the water during sample handling and transfer, or inappropriate use of vacuum sampling device etc. A. Sampling Recommendations Water samples should not be taken immediately following well development Sufficient time should be allowed for the ground water flow regime in the vicinity of the monitoring well to stabilize and to let chemical equilibrium with the well construction materials be approached. This lag time will depend on site conditions and methods of installation but often exceeds one week. Well purging is nearly always necessary to obtain samples of water flowing through the geologic formations in the screened interval. Rather than using a general but arbitrary guideline of purging three casing volumes prior to sampling, it is recommended that an in-line.water quality measurement device (e.g. flow-through cell) be used to establish the stabilization time for several parameters (e.g. ph, specific conductance, redox, dissolved oxygen, turbidity) on a well-specific basis. Data on pumping rate, drawdown, and volume required for parameter stcibilization can be used as a guide for conducting subsequent sampling activities. The following are recommendations to be considered before, during and after sampling: use low flow rates (<0.5 Umin), during both purging and sampling maintain minimal drawdown in the well; maximize tubing wall thickness, minimize tubing length; place the sampling device intake at the desired sampling point; minimize disturbances of the stagnant water column above the screened interval during water level measurement and sampling device insertion; make proper adjustments to stabilize the flow rate as soon as possible; monitor water quality indicators during purging; collect unfiltered samples to estimate contaminant loading and lf"ansport potential in the subsurfa~ system. B. Equipment Calibration Prior to sampling, all sampling device and monitoring equipment should be calibrated according to manufacture's recommendations and the site Quality Assurance Project Plan (QAPP) and Field Sampling Plan (FSP). Calibration of ph should be performed with at least two buffers which bracket the expected range. Dissolved oxygen calibration must be corrected for local barometric pressure readings and elevation. C. Water Level Measurement and Monitoring It is recommended that a device be used which will least disturb the water surface in the casing. Well depth should be obtained from the well logs. Measuring to the bottom of the well casing will only cause resuspension of settled solids from the formation and require longer purging times for turbidity equilibration. Measure well depth after sampling is completed. The water level measurement should be taken from a permanent reference point which is surveyed in relative to ground elevation. D. Pump Type The use of low flow (e.g Lim in) p~mp$ is suggested for purging and sampling all types of analytes. All pumps have some limitation and these should be investigated with respect to application at a particular site. Bailers are inappropriate devices for low-flow sampling. 6

58 1) General Considerations There are no unusual requirements for ground-water sampling devices when using low-flow, minimal drawdown techniques. The major concern is that the device give consistent results and minimal disturbance of the sample across a range of "low" flow rates (i.e. < 0.5 Umin). Clearly, pumping rates that cause minimal to no drawdown in one well could easily cause "significant" drawdown in another w~l finished in a less transmissive formation. In this sense, the pump should not cause undue pressure or temperature changes or physical disturbance on the water sample over a reasonable sampling range. Consistency in operation is critical to meet accuracy and precision goals. 2) Advantages & Disadvantages of Sampling Devices A variety of sampling devices are available for lowflow (minimal drawdown) purging and sampling and include peristaltic pumps. bladder pumps, electrical submersible pumps, and gas-driven pumps. Devices which lend themselves to both dedication and consistent operation at definable low-flow rates are preferred. It is desirable that the pump be easily adjustable and operate reliably at these lower flow rates. The peristaltic pump is limited to shallow applications and can cause degassing resulting in alteration of ph, alkalinity, and some volatiles loss. Gas-drive pumps Should be of a type that does not allow the gas to be in direct contact with the sampled fluid. Clearly, bailers and other "grab" type samplers are ill-suited for low-flow sampling since they will cause repeated disturbance and mixing of "stagnant" water in the casing and the "dynamic" water in the screened interval. Similarly, the use of inertial lift foot-valve type samplers may cause too much disturbance at the point of sampling. Use of these devices also tend to introduce uncontrolled and unac;ceptable operator variability. Summaries of advantages and disadvantages of various sampling devices are listed.in Herzog et al (1991 ), USEPA (1992); Parker (1994) and Thurnblad (1994). Pump Installation Dedicated sampling devices (left in the well) capable of pumping and sampling are preferred over ~ other type of device. Any portable sampling device should be slowty and carefully lowered to the middle of the screened interval or slightly above the middle (e.g m below the top of a 3 m screen). This is to IT'!inimize excessive mixing of the stagnant water in the casing above the screen with the screened interval zone water, and to minimize resuspension of solids which will have collected at the bottom of the well. These two disturbance effects have been shown to directly affect the time required for purging. There also appears to be a direct correlation between size of portable sampling devices relative to the well bore and resulting purge volumes and times. The key is to minimize disturbance of water and solids in the well casing. F. Filtration Decisions to filter samples should be dictated by sampling objectives rather than as a "fix" for poor sampling practices, and field-filtering of certain constituents should not be the default. Consideration should be given as to what the application of field-filtration is trying to accomplish. For assessment of truly dissolved (as opposed to operationally "dissolved" pe. samples filtered with Jm filters]) concentrations of major ions and trace metals, 0.1 1Jm filters. are recommended although 0.45 IJm filters are normally used for most regulatory programs. Alkalinity samples must also be filtered if significant particulate calcium carbonate is suspected, since this material is likely to impact alkalinity titration results (although filtration itself may alter the C0 2 composition of the sample and therefore affect the results). Although filtration may be appropriate, filtration of a sample may cause a number of unintended changes to occur (e.g. oxidation. aeration) possibly leading to filtration-induced artifacts during sample analysis and uncertainty in the results. Some of these unintended changes may be unavoidable but the factors leading to them must be recognized.. Deleterious effects can be minimized by consistent application of Cf;trtain filtration guidelines. Guidelines should address selection of filter type, media, pore size, etc. in order to identify and minimize potential sources of uncertainty when tittering samples. In-line filtration is recommended because it provides better consistency through less sample handling, and minimizes sample exposure to the atmosphere. In-line filters are available in both disposable (barrel filters) and nondisposable (in-line filter holder, flat membrane filters) formats and various filter pore sizes ( IJm). Disposable filter cartridges have the advantage of greater sediment handling capacity when compared to traditional membrane filters. Filters must be pre-rinsed following manufacturer's recommendations. If there are no recommendations for rinsing, pass through a minimum of 1 L of ground water following purging and prior to sampling. Once filtration has begun, a filter cake may develop as particles larger than the pore size accumulate on the filter membrane. The result is that the effective pore diameter of the membrane is reduced and particles smaller than the stated pore $ize are excluded from the filtrate. PoSsible corrective measures include prefiltering (with larger pore size filters), minimizing particle loads to begin with, and reducing sample volume. G. Monitoring of Water Level and Water Quality Indicator Parameters Check water level periodically to monitor drawdown in the well as a guide to flow rate adjustment. The goal is. minimal drawdown (<0.1 m) during purging. This goal may be difficult to achieve under some circumstances due to geologic heterogeneities within the screened interval, and may require adjustment based on site-specific conditions and personal experience. In-line water quality indicator parameters should 7

59 be continuously monitored during purging. ljle water quality indicator parameters monitored can include ph, redox potential, conductivity, dissolved oxygen (DO) and turbidity. The last three parameters are often most sensitive. Pumping rate, drawdown, and the time or volume required to obtain stabilization of parameter readings can be used as a future guide to purge the well. Measurements should be taken every three to five minutes if the above suggested rates are used. Stabilization is achieved after all parameters have stabilized tor three successive readings. In lieu of measuring all five parameters a minimum. subset would include ph, conductivity, and turbidity or DO. Three successive readings should be within± 0.1 tor ph,± 3% for conduc::tivity, ± 10 mv for redox potential, and ± 1 0"/o for turbidity and DO. Stabilized purge indicator parameter trends are generally obvious and follow either an exponential or asymptotic change to stable values during purging. Dissolved oxygen and turbidity usually require the longest time for stabilization. The above stabilization guidelines are provided for rough estimates based on experience. H. Sampling, Sample Containers, Preservation and Decontamination Upon parameter stabilization, sampling can be initiated. If an in line device is used to monitor water quality parameters, it should be disconnected or bypassed during sample collection. Sampling flow rate may remain at established purge rate or may be adjusted slightly to minimize aeration, bubble formation. turbulent filling of sample bottles, or loss of volatiles due to extended residence time in tubing. Typically, flow rates less than 0.5 Umin are appropriate. The same device should be used for sampling as was used tor purging. Sampling should occur in a progression from least to most contaminated well if this is known. Generally, volatile (e.g. solvents and fuel constituents) and gas sensitive (e.g. Fe2-, CH 4, H 2 SIHS, alkalinity) parame:ers should be sampled first. The sequence in which samples tor most inorganic parameters are collected is immaterial unless filtered (dissolved) samples are desired. Filtering should be done last and in-line filters should be used as discussed above. During both well purging and sampling, proper protective clothing and equipment must be used based upon the type and level of contaminants present. The appropriate sample container will be prepared in advance of actual sample collection tor the analytes of interest and include sample preservative where necessary. Water samples should be collected direct1y into this container from the pump tubing. Immediately after a sample bottle has been filled, it must be preserved as specified in the site Quality Assurance Project Plan (QAPP). Sample preservation requirements are based on the analyses being performed (use site QAPP, FJeld Safety Plan [FSP), USEPA, 1992 RCRA guidance document. or EPA-SW-846). It may be advisable to add preservatives to sample bottles in a controlled setting prior to entering the field in order to reduce the chances of improper1y preserving sample bottles or introducing field contaminants into a sample bottle while adding the preservatives. The preservatives should be transferred from the chemical bottle to the sample container using a disposable. polyethylene pipet and the disposable pipet should be used only once and then discarded. After a sample container has been filled with ground water, a Teflon (or tin)-lined cap is screwed on tightly to prevent the container from leaking. A sample label is filled out as specified in the Field Sampling Plan (FSP). The samples should be stored inverted at 40C. Specific decontamination protocols for sampling devic:es are dependent to some extent on the type of device used and the type of contaminants encountered. Refer to the site QAPP and FSP for specific requirements. I. Blanks The following blanks should be collected: (1) field blank: one field blank should be collected from each source water (distilled/deionized water) used for sampling equipment decontamination or for assisting well development procedures. (2) equipment blank: one equipment blank should be taken prior to the commencement of field wort<, from each set of sampling equipment to be used tor that day. Refer to site OAPP or FSP for specific requirements. (3) trip blank: a trip blank is required to accompany each volatile sample shipment. These blanks are prepared in the laboratory by filling a 40-ml volatile organic analysis (VOA) bottle with distilled/deionized water. V. Low-Permeability Formations and Fractured Rock The overall sampling program goals or sampling objectives will drive how the sampling points are located, installed, and choice of sampling device.. Ukewise, shespecific hydrogeologic factors will affect these decisions. Sites with very low permeability formations or fractures causing discrete flow channels may require a unique monitoring approach. Unlike water supply wells,. wells installed tor ground-water quality assessment and restoration programs are often installed in low water-yielding settings (e.g. clays, silts). Alternative types of sampling points and sampling methods are often needed in these types of environments, because low-permeability settings may require extremely low-flow purging {<0.1 Umin) and may be technology-limited. Where devices are not readily available 8

60 to pump at such low flow rates, the primary Consideration is to avoid dewatering of the well screen. This may require repeated recovery of the water during purging while leaving the pump in place within the well screen. Use of tow-flow techniques may be impractical in these settings. depending upon the water recharge rates. The sampler and the end-user of data collected from such wells need to understand the limitations of the data collected, i.e. a strong potential for underestimation of actual contaminant concentrations for volatile organics, potential false negatives for filtered metals and potential false positives for unfiltered metals. It is suggested that comparisons be made between samples recovered using low-flow purging techniques and samples recovered using passive sampling techniques (i.e. two sets of samples). Passive sample collection would essentially entail acquisition of the sample with no or very little purging using a dedicated sampling system installed within the screened interval or a passive sample collection device. A. Low-Permeability Formations (<().1 Umin teeharge) 1. Low-Flow Purging and Sampling with Pumps a. "portable or non-dedicated mode*- Lower.the pump (one capable of pumping at <0.1 Umin) to mid-ween or slightly above and set in place for minimum of 48 hours (to lessen purge volume requirements). After 48 hours. use procedures listed in Part IV above regarding monitoring water quality parameters to~ stabilization, etc., but do not dewater the screen. If excessive drawdown and slow recovery is a problem. then alternate approaches such as those listed below may be better. b. "dedicated mode" - Set the pump as above at least a week prior to sampling; that is, operate'in a dedicated pump mode. With this approach significant reductions in purge volume should be realized. Water quality parameters should stabilize quite rapidly due to less disturbance of the sampling zone. 2. Passive Sample Colle:ction Passive sampling collection requires insertion of the device into the screened interval for a sufficient time period to allow flow and sample equilibration before extraction for analysis. Conceptually, the extraction of water from low yielding formations seems more akin to the collection of water from the unsaturated zone and passive sampling t~niques may be more appropriate in terms of obtaining representative samples. Satisfying usual sample volume requirements is typically a problem with this approach and some ~atitude will be needed on the part of regulatory entities to achieve sampling objectives. B. Fractured Rock In fractured rock formations, a low-flow to zero purging approach using pumps in conjunction with packers to isolate the sampling zone in the borehole is suggested. Passive multi-layer sampling devices may also provide the most representative* samples. It is imperative in these settings to identify flow paths or water-producing fractures prior to sampling using tools such as borehole flowmeters and/or other geophysical tools. After identification of water-bearing fractures, install packer(s) and pump assembly for sample collection using low-flow sampling in "dedicated mode* or use a passive sampling device which can isolate the identified water bearing fractures. VI. Documentation The usual practices for documenting the sampling event should be used for low-flow purging and. sampling techniques. This should include, at a minimum: information on the conduct of purging operations (flow-rate, drawdgwn, water-quality parameter values, volumes extracted and times for measurements), field instrument calibration data, water sampling forms and chain of custody forms. See Figures 2 and 3 and "Ground Water Sampling Workshop - A Workshop Summary" (USEPA, 1995) for example forms and other documentation suggestions and information. This information coupled with laboratory analytical data and validation data are needed to judge the useability" of the sampling data. VII. References 1. Backhus, D,A., J.N. Ryan, D.M. Groher, J.K McFarlane, and P.M. Gschwend Sampling Colloids and Colloid Associated Contaminants in Ground Water. Ground Water, 31 (3): Barcelona, M.J., J.A. Helfrich, E.E. Garske, and J.P. Gibb A laboratory evaluation of groundwater sampling mechanisms. Ground Water Monitoring Revie~. 4(2) : Barcelona, M.J. and J.A. Helfrich Well construction and purging effects on ground-water samples. Environ. Sci. Techno/. 20(11): Barcelona. M.J., H.A. Wehrmann, and M.D. Varljen Reproducible well purging procedures and VOC stabilization criteria for ground-water sampling. Ground Water. 32(1): Buddemeier, R.W. and J.R. Hunt Transport of Colloidal Contaminants in Ground Water:.Radionuclide Migration at the Nevada Test Site. Applied Geochemistry, 3,

61 6. Danielsson, L.G On the Use of Filters for Distinguishing Between Dissolved and Particulate Fractions in Natural Waters. Water Research, 16: Enfield, C.G. and G. Bengtsson Macromo l ect.~lar Transport of Hydrophobic Contaminants in Aqueous Environments. Ground Water26(1 ): Gschwend, P.M. and M.D. Reynolds Monodisperse Ferrous Phosphate Colloids in an Anoxic Groundwater Plume, J. of Contaminant Hydro/. 1, Herzog, B., J. Pennino, and G. Nielsen Ground Water Sampling, in D.M. Nielsen, ed. Practical Handbook of Ground-Water Monitoring. Lewis Publishers,. Chelsea, MI. pp Horowitz, A.J., K.A. Elrick, and M.A. Colberg The effect of membrane filtration artifacts on dissolved trace element concentrations. Water Res. 26(6): Laxen, D.P.H. and I.M. Chandler Comparison of Filtration Techniques for Size Distribution in Freshwaters. Analytical Chemistry, 54(8): McCarthy, J.F. and J.M. Zachara Subsurface Transport of Contaminants, Environ. Sci. Techno/., 5(23): McCarthy, J.F. and C. Degueldre Sampling and Characterization of Colloids and Particles in Ground Water for Studying Their Role in Contaminant Transport. In: Environmental Particles (eds. Buffle, J. and van Leeuwen H.P.), Lewis Pub!.. pp Puis, R.W. and R.M. Powell Acquisition of Representative Ground Water Quality Samples for Metals. Ground Water Monitoring Review, 12(3), Puis, R.W., D.A. Clark, B.Biedsoe, A.M. Powell, and C.J. Paul Metals in Ground Water: Sampling Artifacts and Reproducibility. Hazardous Waste and Hazardous Materials, 9(2). 21. Puis. R.W. and C.J. Paul Low-Flow Purging and Sampling of Ground-Water Monitoring Wells with Dedicated Systems. Ground Water Monitoring and Remediation, 15(1 ): Ryan, J.N. and P.M. Gschwend Colloid Mobilization in Two Atlantic Coastal Plain Aquifers, Water Resour. Res. 26, Thumblad, T.. ~994. Ground Water Sampling Guidance: Development of Sampling Plans, Sampling Protocols, and Sampling Reports. Minnesota Pollution Control Agency. 24. USEPA RCRA Ground-Water Monitoring: Or~ft Technical Guidance, Office of Solid Waste, EPA/530-R , PB , Washington, DC. 25. USEPA Ground Water Sampling Workshop- A Workshop Summary, Dallas, TX, November 30- December EPA/600/R-94/205, 126 pp. 26. USEPA Test Methods for Evaluating Solid Waste, PhysicaVChemical Methods, EPA SW-846. Office of Solid Waste and Emergency Response, Washington D.C. 14. Parker. LV The Effects of Ground Water Sampling Devices on Water Quality: A Literature Review. Ground Water Monitoring and Remediation, 14(2): Penrose. W.R., W.L. Polzer, E.H. Essington, D.M. Nelson, and K.A. Orlandini Mobility of Plutonium and Americium through a Shallow Aquifer in a Semiarid Region, Environ. Sci. Techno/., 24: Puis. R.W. and M.J. Barcelona Filtration of Ground Water Samples for Metals Analyses. Hazardous Was(e and Hazardous Materials 6(4): Puis, R.W. J.H. Eychaner, and A.M. Powell Colloidal-Facilitated Transport of Inorganic Contaminants in Ground Water: Part I. Sampling Considerations. U.S. Environmental Protection Agency Environmental Research Brief, EPA/600/M-90/ Puis, R.W Colloidal Considerations in Groundwater Sampling and Contaminant Transport Predictions. Nuclear Safety, 31 (1 ):