ALDERWOOD WATER & WASTEWATER DISTRICT LYNNWOOD, WASHINGTON WATER QUALITY COLIFORM AND D/DBP MONITORING PLAN

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1 ALDERWOOD WATER & WASTEWATER DISTRICT LYNNWOOD, WASHINGTON WATER QUALITY COLIFORM AND D/DBP MONITORING PLAN Prepared: March 2002 Updated: July 2009

2 ALDERWOOD WATER & WASTEWATER DISTRICT WATER QUALITY MONITORING PLAN TABLE OF CONTENTS Page Number General Description... :... 1 Population Served... 1 Source of Supply... 1 Facilities Description... 2 Disinfecting Facility... 2 Monitoring and Sampling Plan... 3 Coliform Sampling... 4 TTHM and HAA5 Sampling... 5 Chlorine and Chlorimines... 5 List of Figures Water Service Area and Adjacent Purveyors... Figure 1 Water Supply Facilities... Figure 2 Monitoring Location Map... Figure 3 List of Tables Coliform Monitoring Sampling Locations... Table 1 Appendix "A" DOH Memorandum on Monitoring Requirements... App. A Appendix "B" Sample D/DBP Quarterly Reports... App. B Appendix "C" Standard Coliform Sample Gathering Guidelines... App. C i

3 General Description Alderwood Water & Wastewater District (District) is a special purpose District located in Southwest Snohomish County (see Figure 1). The District is authorized as a public Water and Sewer service provider under the provisions of Revised Code of Washington (RCW) Title 57. The District's service area is approximately 60 square miles and includes providing direct retail water service to the City of Brier and portions of the Cities of Bothell, Mukilteo, Mill Creek, and Lynnwood, and unincorporated areas of Southwest Snohomish County. The District also provides wholesale water to the Cities of Lynnwood, Mountlake Terrace, and Edmonds. The District's main source of water supply is from the City of Everett. The District maintains one artesian well (Well No. 5) that has a small transient population of between 1 and 1,000 population served per month. The emphasis of this plan is monitoring of the main source of supply from the City of Everett. However the artesian well site is also listed and monitored in accordance with regulatory requirements. The District's water system identification numbers are 01300E for the Everett Source of Supply, which is 99.9% of the population served and 01319B for the Well No. 5. The District is considered a full utility service provider. Population Served The District provides domestic, commercial, and industrial retail water supply to a total population of approximately 157,800 (as of 2008). This population includes only the District's direct service customers and excludes wholesale customers. The wholesale customers manage their respective public water systems in accordance with WAC Well No. 5 (PWSID No B) serves less than 1,000 customers per month. Source of Supply The District receives treated and filtered water from the City of Everett. Everett s raw water supply originates from Spada Reservoir created by Culmback Dam on the Sultan River approximately 25 miles east of Everett. Raw water is delivered to Chaplain Reservoir through a 246 mgd water supply pipeline after passing through the Snohomish County PUD No. 1 Power House. Raw water from Chaplain Reservoir is treated at Everett s Water Filtration Plant for delivery to the City's water customers 1

4 through four transmission pipelines. The City of Everett s filtered water is chlorinated and the ph is adjusted by adding Soda Ash. The City of Everett also adds fluoride at 1 mg/l. The District's main supply is through Everett's Pipeline No. 5 to Everett's Reservoir No. 3. The water is then pumped from Everett's Reservoir No. 3 by the District's Pump Station Nos. I and 2 to the District's main terminal storage reservoirs. The District also is supplied from Everett s Pipeline No. 5 through the Clearview Water Supply Agency s pump station and reservoir. The Clearview Water Supply Agency s members are Alderwood Water & Wastewater District, Cross Valley Water District, and Silver Lake Water & Sewer District. Facility Description The District s water system consists of over 610 miles of pipeline, four water service pressure zones, eight existing reservoirs with a total storage capacity of 89.9 million gallons, two existing water supply pump stations with a combined capacity of 50 million gallons per day, one booster pump station, and three active and two inactive (emergency standby) pressure reducing stations. In addition, the Clearview Water Supply Agency of which the District is a member has a 12 million gallon reservoir and a 33 mgd pump station. The District's water supply facilities are shown on Figure 2. Disinfecting Facility In addition to the above, ClorTec on-site sodium hypochlorite generation systems are located at Reservoir No. 1, Reservoirs No. 2 and 3, the Canyon Park Reservoir, and the Nike Reservoir. The chlorination equipment is housed in a building specifically designed for the equipment. The District's disinfection equipment produces a dilute 0.8% sodium hypochlorite solution. This percentage is below the concentration threshold for hazardous materials (1%). The process is simple and straightforward: salt is dissolved with water to form a concentrated brine solution, the brine proportioner dilutes and supplies a 3% solution to the electrolytic cell(s), the cells electrolyze the diluted brine into an 0.8% sodium hypochlorite solution, hydrogen is contained and safely vented to atmosphere, the hypochlorite solution is delivered to a day-tank for storage, a metering pump delivers the solution to an injection point in the treatment system. When the tank level drops, the system automatically starts and replenishes the supply of hypochlorite. The system is self-regulating and will shut off if a low brine concentration is detected. Producing one pound of chlorine equivalent requires 3.5 pounds of salt, 2.5 kwh electricity and 15 gallons of water. A programmable logic controller (PLC) monitors every aspect of the operation. This technology greatly improves disinfection 2

5 management by processing and reporting operating parameters, system status and alarm conditions. The disinfection facility at Reservoir No. 1 has the ability to inject chlorine solution into both the reservoir inlet pipeline and the outlet pipeline. The District normally doses the outlet at approximately 0.7 ppm. The outlet dosage is adjusted to maintain the desired residual level at several outlying areas in the distribution system. The disinfection facility at Reservoir Nos. 2 and 3 operates similar to the Reservoir No. 1 facility. Monitoring and Sampling Plan Because the District receives all of the District's water supply from the City of Everett's filtered and treated water system, the District s monitoring and sampling plan is defined as follows (except that Well No. 5 is treated as a well source of supply and is monitored accordingly): WAC Monitoring requirements: (2) Selling and receiving water. (a) Source monitoring. Purveyors, with the exception of those that "wheel" water to their consumers (i,e., sell water that has passed through another purchasing purveyor's distribution system), shall conduct source monitoring in accordance with this chapter for the sources under their control. The level of monitoring shall satisfy the monitoring requirements associated with the total population served by the source. (b) Distribution system monitoring. The purveyor of a system that receives and distributes water shall perform distribution-related monitoring requirements. Monitoring shall include, but not be limited to, the following: (i) Collect coliform samples in accordance with subsection (3) of this section; (ii) Collect trihalomethane samples in accordance with subsection (6) of this section; (iii) Perform the distribution system residual disinfectant concentration monitoring required under WAC or ; (iv) Perform lead and copper monitoring required under 40 CFR , , and ; (v) Perform the distribution system monitoring in accordance with 40 CFR (b) for asbestos if applicable; (vi) Other monitoring as required by the department. 3

6 The City of Everett, as the source of supply purveyor to the District, is responsible for all sampling and maintaining and documenting compliance with all State and Federal requirements relative to source water supply monitoring. Coliform Sampling The District's service population is approximately 157,800 (as of 2008) which requires a minimum of 120 routine samples per month. The attached Table 1 identifies the approximate sampling locations by address. The attached Figure 3 shows the approximate sample locations throughout the District's direct service area. Note that approximately 124 sampling locations are established to complete the minimum 120 routine samples per month. To be representative of the distribution system for the whole month, a minimum of 31 routine samples are taken per week. Quality control is assured by use of a State certified laboratory to supply sampling bottles and perform laboratory analysis. The District's water quality coordinator and water quality program is responsible for maintaining sampling bottles, collecting samples, transporting (via currier service) to certified laboratory and maintaining all sampling records to ensure compliance with adopted practices and State laboratory requirements. In addition to the monthly samples and testing requirements, the District's water quality program monitors chlorine residual concentrations on a daily basis at representative points within the District's water system. Every effort is made to ensure samples are taken at the extreme limits of the District's service area. All records of bacteriological monitoring samples and any related information will be kept and maintained on file for a minimum of five years. Follow Up Action - In the event a coliform positive bacteriological sample is detected and if the sample is not invalidated under State DOH criteria, the District will implement additional actions as defined under WAC , Follow Up Action; Disinfectant/Disinfection Byproduct (D/DBP) Monitoring - The District's Disinfectant/Disinfection Byproduct monitoring Program is intended to comply with CFR A copy of the DOH memorandum describing the federal requirements and the EPA's federal requirements for the D/DBP Rule is included in Appendix A. Quality control is maintained by the District's water quality program. The water quality program ensures all sampling is completed in accordance with adopted protocol and testing is completed by certified testing laboratories. Samples of the District's D/DBP Quarterly Report which are sent to DOH are included in Appendix B. 4

7 TTHM and HAA5 Samplinq To comply with this requirement, the District has identified four areas that can be considered the extreme end of the distribution system. These general sampling areas are shown on Figure 3. The specific locations by street address are: A Alexander Road B Alaska Road C th Place SW D. 244 th and 51 st Avenue SE The District collects and monitors for TTHM s and HAA5 s in accordance with 40 CFR (b)(1)(i). The following is the District s description of how compliance with the rule is calculated (reference DOH memorandum in Appendix "A"): " (1) TTHMs and HAAS. (i) For systems monitoring quarterly, compliance with MCLs in must be based on a running annual arithmetic average, computed quarterly, of quarterly arithmetic averages of all samples collected by the system as prescribed by (b)(1)" (CFR (b)(1)) Because the District is considered to only have 1 "treatment plant" (combining all Everett master meters), the District will average the four TTHM and HAAS samples at the end of March, June, Sept, and Dec beginning in The District will then again average those averages after Dec 2002, and continue to do that at the end of each quarter for the previous 4 quarters. Chlorine and Chloramines The following is the District s description of how compliance with the rule is calculated (reference DOH memorandum in Appendix "A"): (1) Chlorine and chloramines. (i) Compliance must be based on a running annual arithmetic average, computed quarterly, of monthly averages of all samples collected by the system under (c)(1). If the average covering any consecutive fourquarter period exceeds the MRDL, the system is in violation of the MRDL and must notify the public pursuant to , in addition to reporting to the State pursuant to Using the results of chlorine residual measurements collected at the same time as every routine and repeat coliform sample, the District will average results for residual 5

8 chlorine at the end of the month (average of at least 30 values, based on the District s current minimum routine coliform monitoring requirement). In the first year (2002), the District will average the first three months after the end of the first QTR (to be reported by April 10), then the first 6 months after QTR2 (reported by July 10), etc., reporting the first 12 months after the end of 2002 (by Jan 10, 2003). At the end of every quarter thereafter, the running annual average (average of 12 values, one for each month in previous year) will be reported. The District has standard operating guidelines for District employees that specify exact repeat sample collection parameters. All routine sample locations were initially selected with criteria that ensured appropriate available repeat sample collection areas within five water service connections both upstream and downstream of the routine sample location. A copy of the District's Coliform Sampling Guidelines is included in Appendix C. It contains emergency contact information and procedures for District employees to follow should repeat sample sites be required. Emergency contact information is available to all District employees electronically on the District's server and in hardcopy format at locations within the District's Maintenance and Operations building: 6

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