Questions and Answers RFP Sparge Curtain Pilot Study Project

Transcription

1 QUESTIONS ANSWERS Q1 How deep are your shallow monitor wells? A1 The shallow groundwater is located anywhere from 20 to 26 feet below grade. Specifically 20 to 22 feet below grade is where we encounter groundwater most often. There are seasonal variations. Q2 Are we looking to put the sparge points down to 50? A2 For the purposes of the bid document, sparge points have been estimated to be installed to a depth of approximately 50 feet below ground surface. This depth is based on PGW s interpretation of the soil boring logs and the shallow aquifer that is being addressed. As stated in Attachment A, Section Vl. 1 b. of the procurement package, vendor should specify well construction in their proposal. Proposed well construction should be based on the vendor s review of available data, the study objectives and the vendor s experience in past projects of similar nature. As presented in Section 1.1 of the procurement package, the primary study objectives are to evaluate the effectiveness of an AS/SVE system and to collect the data necessary to design a full scale Q3 What other technologies have you looked at other than air sparge/spill vapor extraction? A3 system. The purpose of this project is specifically to look at air sparge/soil vapor extraction as the proposed remedial technology to address VOCs in the groundwater. We haven t looked at any other broad assessments for other alternatives. If you have alternatives you d like to present, we would welcome that for consideration. Following the scope of work on Attachment A, you ll find there is Attachment B on page 42 identifying line items where we want lump sum services for up-front project planning, health and safety plan, and utility location services as needed. We like to build these into project costs as listed in Attachment B. If you feel there are other items that are needed, which are not on this table you are welcome to add them into this table if you feel it s not robust enough. The rest of the Attachments in this RFP are City attachments that are mandated by the City of Philadelphia and some are Procurement Requirements. There are also some Insurance Requirements. Our Risk person is not here today, but you can any questions to annie.wu@pgworks.com and we address them

2 Q4 Q5 Q6 Do have any active treatments or conducting any environmental remediation measures now? Were the test locations picked for any other reason other than wells with high soluble benzene concentrations, utilities or anything like that to consider? Do you have any soft digging requirements prior to drilling; like 3 feet? A4 A5 A6 as soon as possible. No, we do not. The test locations were selected based on the benzene concentrations in the groundwater in the study area. Utilities at Passyunk and/or Porter should be confirmed prior to conducting excavations/drilling activities. In areas where utility clearance is not obtained, soft dig excavation methods should be employed. PGW will identify and confirm the final locations of each test point location prior to initiating project activities Only if it s indicated for utility confirmation purposes. If you get the all clear for utilities, then it s okay to excavate without soft dig requirements. Q7 Can we take photos? A7 Yes, but the PGW Passyunk Plant has restrictions regarding photography. Prior authorization for photos while on Passyunk Plant property is required. Q8 Is all usual safety clothing required? A8 Fire retardant coveralls, steel toe boots, hard hat safety glasses are required for entry and work at the PGW Passyunk Plant. A safety video is shown to contractors it details all safety procedures to be followed while on location. We prefer that you have your contractor s identification on your truck while working here at a PGW facility. Q9 Will be provided with power while working here? Q10 So a generator? Q11 Is that going to be a problem with a hot permit? Q12 All the test locations are at Porter right? Q13 Will we be able to get the vans in the parking area moved if necessary? Q14 Access is through the contractor s gates? Q15 Can we obtain historic depth to water information for the existing monitoring A9 Assume you will need to bring your own power supply, but we will be able to provide you with water. A10 Yes. A11 Not at Porter site, but at the PGW Passyunk Plant we ask that you put in a permit so that PGW may arrange for a fire watch or safety watch as needed. A12 Monitor well 4-S is located at the very end of Porter, so it s considered on the Porter Station property. PGW will identify and confirm the final locations of each test point location prior to initiating project activities A13 Yes. A14 Yes, and contractor vehicles will be allowed onsite if signed in with PGW Security upon entry. A15 Yes. This information will be provided via e- mail.

3 wells? Q16 Is the flow direction depicted on the shallow groundwater contour map from September 20, 2010 representative of typical conditions? Q17 During the pre-proposal meeting it was that a copy of the most recent site report would be distributed to the bidders, when will a copy be available? Q18 Please provide the boring/well construction logs for MWs: -4S, -6S and -11S. Q19 What is the anticipated screened interval for the air sparge pilot test points? Q20 What is the average depth to water (feet below grade) in the pilot test area? Q21 What is the anticipated duration for each of the steps of the three-step (SVE only, AS only & AS/SVE combined) approach pilot study? Q22 What analytical method [TO14 (tedlar bag) or TO15 (summa canister)] should be used for that air sample? Q23 Attachment F of the solicitation shows the proposed pilot test locations. It appears that both locations are on the Porter Facility. Please confirm that both tests can be conducted on the Porter Facility. A16 Yes. We have no data indicating otherwise. A17 This information will be supplied via ASAP. A18 Included in information provided by . A19 PGW requires that vendors specify proposed well construction details with the proposal. (Attachment A, Section Vl. 1 b. of the procurement package). Proposed well construction should be based on the vendor s review of available data, the study objectives and the vendor s experience in past projects of similar nature. As presented in Section 1.1 of the procurement package, the primary study objectives are to evaluate the effectiveness of an AS/SVE system and to collect the data necessary to design a full scale system. A20 This information can be found in the groundwater sampling report which will be provided ASAP. A21 Anticipated durations for each phase of the project should be included in the vendor s proposal. Proposed durations should be based on the vendor s review of available data, the study objectives, and the vendors experience in past projects of similar nature. A22 Analytical methods proposed by the vendor should be included in the vendor s proposal. Anticipated uses of air data include air treatment system sizing, permitting, and estimating system performance. As presented in Section 1.1 of the procurement package, the primary study objectives are to evaluate the effectiveness of an AS/SVE system and to collect the data necessary to design a full scale system. Vendor should propose an analytical method based on reliability, accuracy and usability of the data. A23 The pilot test locations may be located at either the PGW Passyunk Plant or at the PGW Porter Station. It is possible that both test locations can be conducted within the PGW Porter Station. The final test locations have yet to be

4 Q24 The Groundwater Sampling Report: September 2010 prepared by Science Applications International Corporation (SAIC) does not contain information regarding the volatile and semi-volatile organic compounds in soil at the site. The report does refer to prior investigations performed by Weston Solutions, Inc. and others in which identified the presence of these compounds in soil. Would it be possible to obtain the soil data from these investigations in order to evaluate soil contamination levels impact on groundwater quality and the proposed remedial action strategy for the Site? Q25 We would like clarification on the question and answer to Q9. The Sparge / SVE system will require significant power. It is our understanding that PGW does not wish to install an on-site transformer or other source of power for temporary power to the equipment. Therefore, the bidders are requested to evaluate the most beneficial option between providing a generator, or providing a temporary service fed from an confirmed, but PGW will identify and confirm each test point location prior to initiating project activities. A24 Soil data for the PGW Passyunk site will be provided to the selected vendor after award of this RFP. The 2010 SAIC report is focused only on groundwater chemistry and transport at the PGW Passyunk Plant and PGW Porter FSD Station. Previous surface soil and subsurface soil conditions were evaluated at the PGW Passyunk Plant in by Weston Solutions; however, the soils located in the east/southeastern area of the PGW Passyunk Plant and within the PGW Porter FSD Station were not investigated due to infrastructure and access issues. Past studies of soil impacts at the PGW Passyunk Plant have identified sitewide impacts of heavy metals (lead and arsenic) to the surface soils (0-2 feet below grade) above direct contact standards, and sitewide impacts of VOCs (benzene) and SVOCs (benzo-a-pyrene, napthalene, and pyrene) to subsurface soils (0-8 feet below grade) above soil-to-groundwater standards. For contaminant impacts to groundwater quality at the PGW Passyunk Plant, please assume that the elevated BTEX readings in the groundwater are due to the presence of historic LNAPL and DNAPL plumes that are likely located within the east/southeastern region of the PGW Passyunk Plant where a propane tank farm currently resides. PGW is soliciting this pilot test for the purpose of evaluating the effectiveness of implementing sparge/soil vapor extraction technology as an engineering control to address known impacts to the groundwater, without conducting soil/source removal. A25 As indicated in the response to Question 9, Vendors should assume they need to provide power for the pilot testing. The response to Question 10 indicates that the Vendor should provide a generator. Vendors should base their bids on supplying a generator to provide power to the pilot tests. Installation of temporary service poles may be considered at the Porter Station. Vendor

5 off-site location, to power this equipment to be installed? Is it acceptable to install a temporary utility pole on the PGW property proximal to the pilot system(s)? should identify potential cost savings, schedule impacts, and other benefits or considerations in their proposal.