Operations, Maintenance and Monitoring Plan Halesite Former MGP Site

(,(liil hoi,ii I flyiiilililllll1 Ii.IIIJ \X'\l1 r I~l'!lut, I IIglllttllll" Operations, Maintenance and Monitoring Plan Halesite Former MGP Site Halesite, Suffolk County, N ew York AOC Index No. Dl-0001-98-11 Submitted to: National Grid 175 East Old Country Road Hicksville, NY 11801 Submitted by: GEl Consultants, Inc. 110 Walt \'Xlhitman Road, Suite 204 Huntington Station, NY 11746 631-760-9300 May 6, 2009 Project #061140-14-2309, Tcil, PE l)wject Manager

Table of Contents Abbreviations and Acronyms ii 1. Introduction 1 2. Lowland Area Oxygen Injection System 3 2.1 Engineering Control (EC) Plan 3 2.1.1 Identification/Statement of Engineering Controls 3 2.2 Performance Monitoring Plan 3 2.2.1 Soil Vapor and Ambient Air Monitoring 3 2.2.2 Groundwater Monitoring 5 2.3 System Operation and Maintenance Plan 7 2.3.1 System Operation and Maintenance Schedule 8 2.3.2 Operation and Maintenance for Mechanical Systems 8 2.3.3 Operation and Maintenance for the Injection Wells 9 2.3.4 Tools and Spare Parts 9 2.3.5 System Shutdown and Restart 10 2.4 Non-Aqueous Phase Liquid Monitoring and Potential Recovery 10 3. Long-term Groundwater Monitoring 11 4. Quality Control/Quality Assurance 12 5. References 13 Tables 1 Soil Vapor Monitoring Schedule 2 Groundwater Monitoring Well Sampling Schedule Figure 1 Proposed System Location and Monitoring Network Appendices A Maintenance Checklist B Oxygen Injection Operation and Maintenance Log (Typical) H:\WPROC\Project\KEYSPAN\Halesite\OMM Plan\Final 050609\HalesiteOMMPlan.doc i

Abbreviations and Acronyms EC ELAP EPA GEI HPC LIPA MGP msl NAPL NGRID NYSDEC NYSDOH PAH PID O&M OM&M OVM SOP TAL VOC Engineering Controls Environmental Laboratory Approval Program United States Environmental Protection Agency GEI Consultants, Inc. Heterotrophic Plate count Long Island Power Authority Manufactured Gas Plant mean sea level Non-Aqueous Phase Liquid National Grid New York State Department of Environmental Conservation New York State Department of Health Polycyclic Aromatic Hydrocarbon Photoionization Detector Operations and Maintenance Operations, Maintenance and Monitoring Organic Vapor Monitor Standard Operating Procedure Target Analyte List Volatile Organic Compound MEASUREMENTS ppm Parts Per Million ii

1. Introduction This Operations, Maintenance, and Monitoring (OM&M) Plan details the operation, maintenance and monitoring plans for the proposed oxygen injection system in the Lowland Area of the Halesite Former Manufactured Gas Plant (MGP) Site located in Halesite, Suffolk County, New York (Site). This OM&M Plan is prepared and provided in accordance with the requirements of the New York State Department of Environmental Conservation (NYSDEC) comment letter dated March 5, 2009. The Halesite former MGP (also known as the Huntington MGP) is believed to have initiated operations around 1892 and continued to operate through approximately 1918. Structures that had been used for the manufacture of gas were later dismantled and removed from the Site. Following the merger between Long Island Lighting Company and the Brooklyn Union Gas Company, the Halesite former MGP site became the property of Long Island Power Authority (LIPA) due to the presence of the electric substation facility. Additional details regarding the history of the site are provided in the December 2002 Remedial Investigation Report. The Site is about 1-acre in size and is located along North New York Avenue, approximately 200 feet east of Huntington Harbor. An active LIPA electric substation is located on the western third, or Lowland Area, of the Site. The remaining eastern two thirds of the property, or Upland Area, is undeveloped land that is characterized by a steep slope that was formerly heavily vegetated, but was cleared and stabilized with new plantings during site remediation. The surrounding area is primarily residential with a mixture of commercial properties along New York Avenue. The topography of the Site is relatively flat around the existing electric substation in the Lowland Area. The undeveloped Upland portion of the site rises sharply eastward from approximately 20 feet to 60 feet above mean sea level (msl) and continues to slope upward to a highpoint near the northeast corner of the property. The elevation of the Site ranges from about 16 feet above msl near the western boundary of the site in the Lowland Area to approximately 86 feet above msl at the eastern boundary of the Site in the Upland Area. An oxygen injection system will be installed in the Lowland Area to treat groundwater contamination from residual soil contamination that cannot be excavated due to the accessibility issues associated with the steep slopes in the Upland Area and the active electrical substation in the Lowland Area. Oxygen injection enhances the biological degradation of organic contaminants, including petroleum hydrocarbons, by increasing dissolved oxygen concentrations in groundwater to stimulate the growth of indigenous aerobic microbes that degrade these contaminants. Oxygen injection is suitable for shallow 1

groundwater conditions or areas with nearby sensitive receptors since there is no generation of hazardous vapors. This OM&M Plan details the engineering controls (EC) put in place within the Lowland Area of the Site. ECs are defined as the remediation systems or structures intended to treat or facilitate treatment of soil and groundwater impacted with MGP-related compounds. Performance monitoring for the EC will include assessments of their impacts to soil vapor and the groundwater throughout the Site. These monitoring plans are detailed in this OM&M Plan and are intended to evaluate and monitor the effectiveness and performance of the EC. Finally, this OM&M Plan will describe the operation and maintenance plans for the EC. 2

2. Lowland Area Oxygen Injection System 2.1 Engineering Control Plan 2.1.1 Identification/Statement of Engineering Controls (EC) An oxygen injection system distributing oxygen to six separate oxygen injection banks will be installed as the primary engineering control within the Lowland Area. The system will inject oxygen gas at a pulsed rate into the groundwater at various depths through injection lines. These injection lines are constructed to traverse the groundwater plume s flow path and to provide treatment surrounding the LIPA substation. The injected oxygen will create an aerobic environment or treatment zone within the Lowland Area. This environment will stimulate the growth of the native aerobic bacteria and facilitate the biodegradation of the MGP-related contaminant mass as it passes through the treatment zone. Therefore, the oxygen injection system will hasten the reduction of the contaminant mass in the groundwater. 2.2 Performance Monitoring Plan 2.2.1 Soil Vapor and Ambient Air Monitoring The following soil vapor sampling and frequency protocol will be followed to monitor the performance of the proposed oxygen injection system. The sampling protocol for the oxygen injection system may be modified if directed by NYSDEC. Soil vapor sampling protocol will be at a minimum: Prior to system start-up, at least one complete pre-injection round of soil vapor will be collected from all permanent soil vapor monitoring points in the immediate vicinity of the oxygen injection line. During the first day of system start-up, soil vapor samples will be collected from targeted locations twice per day. One of the two sets of samples will be collected immediately prior to system start-up. The second set will be collected during the first injection cycle. Targeted locations will be those soil vapor monitoring points located near or at the oxygen injection points. The locations of the soil vapor monitoring points are summarized in Table 1 and depicted on Figure 1. During Weeks 1-4 of the system start-up period, soil vapor samples will be collected from the targeted soil vapor monitoring point locations twice per week. 3

After the completion of the first four weeks of system operation, the frequency of soil vapor monitoring for the targeted soil vapor monitoring point locations may be reduced to quarterly sampling based on review of analytical sampling results and NYSDEC approval. All soil vapor samples will be analyzed for volatile organic compounds (VOCs) and Naphthalene via Modified United States Environmental Protection Agency (EPA) Method TO-15 by a New York State Department of Health (NYSDOH) Environmental Laboratory Approval Program (ELAP)-certified laboratory. The samples will also be analyzed for Helium and Carbon Dioxide. Samples will be submitted for expedited turn-around time of one week. Soil vapor analytical results will be tabulated prior to validation and transmitted to the NYSDEC and NYSDOH as soon as the data is available. Approximately four weeks after system start-up, NYSDEC and NYSDOH will review the available soil vapor data. Preliminary data, including the baseline and first two weeks of the oxygen injection system operation, will be provided within three weeks of system startup. The laboratory turnaround time accommodates this reporting schedule. If no indications of elevated soil vapor concentrations are observed at any sampling event, then soil vapor sampling will continue according to protocol unless otherwise directed by NYSDEC. Elevated soil vapor concentrations are defined as concentrations above the NYSDOH 95 th percentile concentration for outdoor air or concentrations above pre-start-up data. If elevated soil vapor concentrations are observed after any sampling event, then the data will be compared to the data collected prior to system start-up. This comparison will be conducted to determine if the elevated concentrations are indicative of background concentrations and to identify any potential data trends. If the comparison indicates that the concentrations are background related, then no further action is required. However, if the concentrations do not appear related to background, both the soil vapor point and the background soil vapor point will be re-sampled and analyzed with an expedited laboratory sample turnaround time. The system will be temporarily shut down as soon as the additional samples are collected and will remain down until the analytical results have been received and transmitted to the NYSDEC and NYSDOH. The results of the re-sampling will be transmitted to the NYSDEC and NYSDOH upon receipt and appropriate measures may be taken to mitigate the soil vapor issue. This may include: Temporarily shut-down of the system and additional re-sampling Conduct a soil vapor intrusion sampling event in any occupied property immediately adjacent to the soil vapor sample location (if any) 4

A photoionization detector (PID) or similar organic vapor monitor (OVM) will be used to collect real-time data from one permanent soil vapor point at or near the point of injection during the system start-up period. Per NYSDEC recommendation, a 15-minute time weighted average trigger of 5 parts per million (ppm) over background total VOCs would require a temporary shutdown of the system. Background VOC levels would be determined based on a statistical review of PID readings from soil vapor sampling rounds prior to system start-up. The system may be restarted once the PID readings return to within 5 ppm of background. The permanent soil vapor point sample schedule is summarized in Table 1 for the oxygen injection system, and their locations are detailed on Figure 1. Soil Vapor Sampling procedures are outlined below. The permanent soil vapor points will not be sampled or purged for a minimum of 24 hours after installation. The purge rate shall not exceed 0.2 liters per minute. A suction pump will be used to remove a minimum of three implant/vapor screen volumes from the permanent soil vapor points prior to sampling. Samples will be collected in an individually laboratory certified clean SUMMA canister (or equivalent) using a flow controller. The flow rate will not exceed 0.2 liters per minute. A helium tracer gas will be used to identify any potential migration or short circuiting of ambient air during sampling. All analysis will be performed by a laboratory that holds a current ELAP certification for the appropriate analyte and environmental matrix combinations. All laboratory analytical data will be validated by a data validation professional in accordance with the EPA Contract Laboratory Program National Functional Guidelines for Organic Data Review, January 2005 and the EPA Region II Standard Operating Procedure (SOP) for the Validation of Organic Data modified to accommodate the EPA Method TO-15 and natural gas analysis by ASTM D-1945. 2.2.2 Groundwater Monitoring The following groundwater sampling and frequency protocol will be followed to monitor the performance of the proposed oxygen injection system. NYSDEC requires that targeted groundwater monitoring wells need to be sampled before system start-up and then once per month (monthly) for three months, thereafter. Following the three-month period after startup, NYSDEC may reduce the sampling frequency to quarterly. Otherwise, sampling of the targeted wells will proceed monthly. The analytical results and field measurements will be 5

used to evaluate the performance of the oxygen injection system. Specifically, the data set is focused on monitoring the aerobic environments created by the oxygen injection lines and the bioactivity of the aquifer. The groundwater samples collected from targeted monitoring wells prior to system start-up will be analyzed for: VOCs via EPA Method 8260 Polycyclic aromatic hydrocarbons (PAHs) via EPA Method 8270 Sulfate via EPA Method 375.4 Total Sulfide via EPA Method 375.4 Nitrogen via EPA Method 351.2 Nitrate/Nitrite via EPA Method 353.3 Ammonia via EPA Method 350.1 Target analyte list (TAL) (23) Metals Phosphate via EPA Method 3651 Heterotrophic Plate count (HPC) via ASTM Method 9215B Dissolved Carbon Dioxide via ASTM Method 4500CO2D The groundwater samples collected monthly after system start-up from the targeted monitoring wells will begin one to two weeks after the system is turned on. These samples will be analyzed for: VOCs via EPA Method 8260 PAHs via EPA Method 8270 HPC via ASTM Method 9215B (during the first three months of operation only) The targeted groundwater samples collected on a quarterly basis after system start-up, per NYSDEC approval, will be analyzed for: VOCs via EPA Method 8260/624 PAHs via EPA Method 625/8270 Sulfate via EPA Method 375.4 Total Sulfide via EPA Method 375.4 Nitrogen via EPA Method 351.2 Nitrate/Nitrite via EPA Method 353.3 Ammonia via EPA Method 350.1 TAL (23) Metals Phosphate via EPA Method 3651 HPC via ASTM Method 9215B Dissolved Carbon Dioxide via ASTM Method 4500CO2D 6

The remaining monitoring wells that were not sampled in association with an oxygen injection system start-up will be collected according to its current quarterly sampling schedule. These samples will be analyzed for: VOCs via EPA Method 8260 PAHs via EPA Method 8270 All samples will be collected using low-flow sampling methods. During sample collection, several field parameters will be collected and utilized as additional performance metrics. These field parameters include at a minimum: Dissolved Oxygen Oxidation-Reduction Potential ph conductivity The proposed monitoring well sampling schedule for the oxygen injection system is summarized in Table 2 and the monitoring well locations are detailed on Figure 1. National Grid (NGRID) will report the results of the pre-startup and first monthly sampling event to the NYSDEC in a Remediation System Startup Summary 45 days after the monthly sample results are received and validated. Subsequent sample results will be reported as available in the quarterly OM&M reports as further discussed in Section 3.0. 2.3 System Operation and Maintenance Plan The system operation and maintenance (O&M) plan will be focused on ensuring the oxygen injection system is operating according to design and manufacture. This includes inspecting the integrity of the injection lines, injection points, oxygen generating equipment and machinery. More specifically, the primary objectives of O&M tasks will be focused on the following: Inspect the oxygen injection system and all of its components (i.e. oxygen generator, air compressor, etc.). Inspections will ensure the remediation equipment is performing as designed (injection rates, cycles, and pressures; injected oxygen concentrations, etc.). Inspection of the remote communication abilities with the remediation systems will be checked weekly throughout the duration of the system s operation. Perform routine operation and maintenance on the mechanical equipment per manufacture s instruction. 7

Measure and record system injection parameters. Compare these parameters to the monitoring data generated by the activities described in subsections 2.2 and 2.3. Based on this data comparison, the injection system may be adjusted to optimize its performance. Record operational and monitoring data, as well as major system adjustments (e.g., an increase or decrease in oxygen injection cycle rates) for documentation in the quarterly OM&M reports. Monitor the purity of the oxygen being manufactured by the system and subsequently injected into the groundwater. These objectives are described in more detail below. In order to accomplish the objectives of the post construction operation and monitoring program, the schedule and tasks described below will be followed. A binder that contains manuals provided by the equipment manufacturers will be stored in each equipment enclosure for as-needed reference during performance of the O&M activities. 2.3.1 System Operation and Maintenance Schedule During the first week of system start-up, O&M activities will be performed daily. For the rest of the first month of operation, O&M activities will be performed weekly. Following the first month of operation, O&M activities will be performed monthly. If needed, system adjustment and maintenance of fluid levels, lubrication, filtration units, and connectors will be performed during each site visit. Full maintenance of the mechanical components of the oxygen injection system will be performed every six months or as recommended by the equipment manufacturers. 2.3.2 Operation and Maintenance for Mechanical Systems O&M tasks for the mechanical components include system inspection, data recording, and field measurements. During each O&M inspection visit, the following tasks will be performed: Inspection of the system enclosure and mechanical equipment for security problems (i.e., vandalism, system damage, operating anomalies, equipment or conveyance malfunction, connection integrity, power outages, or environmental effects). Inspection of fluid levels, filter conditions, connectors, and timer settings. Recording of Airsep Oxygen Generator, Kaesar Compressor, and Pulse Cycle Timer settings and/or readings. Recording of the Oxygen Purity from the Oxygen Feed Tank. 8

Documentation of the inspection results on the field log form. Samples of a maintenance checklist and O&M Log Sheet are included in Appendix A and Appendix B of this O&M Plan. Approximately every six months, or as recommended by the equipment manufacturers, additional maintenance tasks will be performed on the oxygen injection mechanical equipment. These tasks will include changing out air and oil filters, replacing gaskets on the filter housings, and replacing lubricating oils used in the mechanical equipment. In addition, valves, motors, and belts will be checked to ensure that they are in good condition and additional maintenance will be performed if warranted. Used lubricating oils and oil filters will be taken to an off-site recycling facility for proper disposal. Air filters and gaskets replaced during system maintenance will be disposed of as solid waste. 2.3.3 Operation and Maintenance for the Injection Wells O&M tasks for the injection wells are minimal because there are no mechanical components. During each monthly inspection visit, the following tasks will be performed: Record oxygen injection pressures and flow rates for each of the injection wells that are connected to the injection manifold in the system enclosure. Document the inspection results in a field book and on the field log form. During the O&M visits, periodic field adjustments in delivery pressures and flow rates may be needed and will be based upon evaluation of the collected field and groundwater analytical data. In addition, recorded data will be evaluated in the field to determine if there is a problem with any of the injection wells (e.g., any injection well with high flow rates but lower than expected pressures may have leaks). 2.3.4 Tools and Spare Parts All tools required for the O&M tasks will be stored in the oxygen injection equipment enclosure. One complete set of spare parts used in the six-month maintenance tasks (e.g., oil, filters, and gaskets) will be obtained from the equipment vendors and stored in the system enclosure. These spare parts will be available at all times in case repairs are required during any of the O&M site visits. An additional set will be ordered prior to performance of the six month maintenance tasks so that they can be available for future site visits. 9

Personal protective equipment, (e.g., gloves, earplugs), will be maintained in the system enclosure for use during the site visits. Housekeeping supplies, (e.g., towels, broom) will also be stored in the system enclosure so that the working space and equipment can be kept clean and in orderly condition. Used person protective equipment and cleaning supplies will be disposed of as solid waste. 2.3.5 System Shutdown and Restart The oxygen injection system is equipped with a pressure sensor on the outlet of the receiver tank attached to the compressor. If the system shuts down, pressure in the compressor tank will drop and the sensor will activate telemetry that will be programmed to contact the system operator. The telemetry is also interfaced with the digital output of the compressor unit allowing for remote access to system information. Following notification of shutdown, the operator will go to the system enclosure location to determine the cause of the shutdown and make the system operational, if possible. Specialized support from the remedial system or equipment vendors may be needed and this will be arranged if needed. 2.4 Non-Aqueous Phase Liquid Monitoring and Potential Recovery The 13 passive non-aqueous phase liquid (NAPL) recovery wells, installed on the perimeter of the Lowland, will be monitored for the presense of NAPL. The locations of the NAPL recovery wells are depicted on Figure 1. The passive recovery wells will be gauged for the presense of NAPL twice per week for Weeks 1-4 of system startup. The gauging will be conducted concurrent with the soil vapor sampling (described in subsection 2.2.1). The NAPL gauging will be conducted using an interface probe. The interface probe will be decontaminated between wells. If NAPL is encountered, attempts will be made to recover it, to the extent feasible. The NAPL recovery may involve bailing or pumping. The product will be transferred to DOT-approved 55- gallon drums, and staged on site for appropriate subsequent disposal. The NAPL gauging and recovery information (including thickness, volume recovered, time and date, and other pertinent information) will be recorded in a dedicated field notebook and transcribed onto a well gauging information sheet. The NYSDEC will be immediately notified if trace or recoverable product is observed in any of the recovery wells. If warranted, based on the findings of this 4-week gauging, a long term NAPL monitoring and recovery program will be coordinated between NYSDEC and NGRID. The well gauging sheets will be provided to NYSDEC on, at the least, a weekly basis. 10

3. Long-term Groundwater Monitoring Long-term groundwater monitoring will consist of the monitoring conducted as part of the existing quarterly groundwater monitoring program along with the groundwater monitoring conducted as part of the oxygen injection performance monitoring described in subsection 2.2.2. The specific wells for each of these programs are identified in Table 2 and the well locations are depicted in Figure 1. The scope of each program will be evaluated on at least an annual basis. Any recommendations for modifications to the monitoring program will be provided to the NYSDEC and NYSDOH for approval. 11

4. Quality Control/Quality Assurance Duplicate samples, matrix spike/matrix spike duplicates, and field blanks will be collected for all soil and groundwater samples. A minimum of one duplicate sample, one matrix spike/matrix spike duplicate, and one field blank will be collected for every twenty samples collected. Trip blanks will be included with each data set submitted to the laboratory. Following the completion of soil vapor and monitoring well sampling, the analytical results will be validated by qualified data validation professionals in accordance with EPA Contract Laboratory Program National Functional Guidelines for Organic Data Review, January 2005 and the EPA Region II SOP for the Validation of Organic Data acquired using SW-846 8260B and 8270C, modified to accommodate the SW-846 methodologies. 12

5. References Dvirka and Bartilucci (D&B), December 2002, Halesite Former Manufactured Gas Plant Site Remedial Investigation Report. New York State Department of Health, 2005, Guidance for Evaluating Soil Vapor Intrusion in the State of New York, revised April 2005. http://www.health.state.ny.us/nysdoh/gas/ svi_guidance/index.htm New York State Department of Environmental Conservation, December 2002. Draft DER-10 Technical Guidance for Site Investigation and Remediation. Vanasse Hangen Brustlin, Inc. (VHB), April 2004. Halesite Former Manufactured Gas Plant Site Final Remedial Investigation Report, Town of Huntington, New York. GEI Consultants, Inc. (GEI), March 2006, Halesite former Manufactured Gas Plant Site Remedial Action Plan. AKRF Engineering P.C., February 2008, Remedial Design Work Plan, Halesite Former Manufactured Gas Plant Site. 13

Tables

Table 1 Soil Vapor Monitoring Schedule Operations, Maintenance and Monitoring Plan Halesite Former MGP Site Halesite, New York Monitoring Well ID Pre-System Start-up Twice Daily Sampling (Day 1) Daily Sampling (Day 3-5) Weekly Sampling (Week 2-4) Quarterly Sampling Total Samples Collected in Year 1 Location Proposed Permanent Soil Vapor Point SG-1 1 2* 1 6 3** 13 Southern Injection Line SG-2 1 2* 1 6 3** 13 Southern Injection Line SG-3 1 2* 1 6 3** 13 Southern Injection Line SG-4 1 2* 1 6 3** 13 Southern Injection Line SG-5 1 2* 1 6 3** 13 Northern Injection Line SG-6 1 2* 1 6 3** 13 Northern Injection Line SG-7 1 2* 1 6 3** 13 Northern Injection Line SG-8 1 2* 1 6 3** 13 Northern Injection Line Notes: * - First round of samples will be collected immediately prior to system start-up. The second round of samples will be collected after one complete injection cycle. ** - Soil vapor sampling frequency may move to quarterly with approval from NYSDEC. All samples will be analyzed using Modified TO-15 including Naphthalene and C02. A duplicate sample will be collected for every 20 samples for QA/QC. Page 1 of 1 H:\WPROC\Project\KEYSPAN\Halesite\OMM Plan\Final 050609\Table 1 and 2 Halesite OMM.xls

Table 2 Groundwater Monitoring Well Sampling Schedule Operations, Maintenance and Monitoring Plan Halesite Former MGP Site Halesite, New York Monitoring Well ID Screen Interval (Feet bgs) Pre-System Start-up Monthly VOC, PAH and HPC Sampling Quarterly Performance Sampling Quarterly VOC and PAH Sampling Total Samples Collected in Year 1 Performance Monitoring Wells HHMW-05S1-R 6-11 1* 3 3* -- 7 HHMW-05S2-R 18-28 1* 3 3* -- 7 HHMW-16S1 15-20 1* 3 3* -- 7 HHMW-16S2 25-35 1* 3 3* -- 7 HHMW-17S1 12-17 1* 3 3* -- 7 HHMW-17S2 22-32 1* 3 3* -- 7 HHMW-18S1 7-12 1* 3 3* -- 7 HHMW-18S2 17-27 1* 3 3* -- 7 HHMW-19S1 2-7 1* 3 3* -- 7 HHMW-19S2 15-25 1* 3 3* -- 7 HHMW-20S1 2-7 1* 3 3* -- 7 HHMW-20S2 15-25 1* 3 3* -- 7 HHMW-21S1 2-7 1* 3 3* -- 7 HHMW-21S2 15-25 1* 3 3* -- 7 HHMW-22S1 3-8 1* -- 3* -- 4 HHMW-22S2 13-23 1* -- 3* -- 4 HHMW-15S 5-10 1 -- -- 3 4 Supplemental Monitoring Wells (sampled as part of existing Quarterly Monitoring Program) MW-03 2-12 Q1 2009 -- -- 3 4 MW-04 1-21 Q1 2009 -- -- 3 4 HHMW-04I 30-40 Q1 2009 -- -- 3 4 HHMW-06S1 2.5-7.5 Q1 2009 -- -- 3 4 HHMW-06S2 12-22 Q1 2009 -- -- 3 4 HHMW-06I 35-45 Q1 2009 -- -- -- 0 HHMW-07S1 3-8 Q1 2009 -- -- 3 4 HHMW-07S2 16-26 Q1 2009 -- -- 3 4 HHMW-07I 45-55 Q1 2009 -- -- -- 1 HHMW-07D 115-125 -- -- -- -- 0 HHMW-08S 2-12 Q1 2009 -- -- 3 4 HHMW-08I 35-45 -- -- -- -- 0 HHMW-09S1 6-11 Q1 2009 -- -- 3 4 HHMW-09S2 17.5-27.5 Q1 2009 -- -- -- 1 HHMW-09I 43-53 Q1 2009 -- -- 3 4 HHMW-09D 85-95 Q1 2009 -- -- 3 4 HHMW-11S 3-13 Q1 2009 -- -- 3 4 HHMW-11I 31-41 Q1 2009 -- -- 3 4 HHMW-13 39-49 Q1 2009 -- -- 3 4 HHMW-14 64-74 Q1 2009 -- -- 3 4 Notes: 1) * Samples will be analyzed for VOCs, PAHs, Sulfate, Sulfide, Nitrogen, Nitrate/Nitrite, Ammonia, TAL (23) Metals, Phosphate, Heterotrophic Plate Count (HPC), and Dissolved Carbon Dioxide. 2) HHMW-15S, HHMW-22S1, HHMW-22S2 will not be sampled as part of the monthly monitoring due to the property access restrictions. Page 1 of 1 H:\WPROC\Project\KEYSPAN\Halesite\OMM Plan\Final 050609\ Table 1 and 2 Halesite OMM.xls

Figure

Appendix A Maintenance Checklist

Maintenance Checklist 1) Inspect site enclosure and landscaping, record condition of fencing and landscaping noting any vandalism or other problems. Also record any corrective actions or contacts made to initiate corrective actions. 2) Inspect trailer (interior and exterior) and mechanical equipment, record condition of trailer and the presence of any problems with mechanical equipment (e.g., oil leaks). Also record any corrective actions or contacts made to initiate corrective actions. 3) Perform operation and maintenance tasks and list observations on Oxygen Injection Operation and Maintenance Log Sheet. 4) Record system condition when leaving the site (e.g., trailer and enclosure locked, trash removed from interior and exterior of trailer, whether or not the system is functioning, and any abnormal site conditions).

Appendix B Oxygen Injection Operation and Maintenance Log (Typical)

OXYGEN INJECTION OPERATION AND MAINTENANCE LOG Halesite Former Manufactured Gas Plant Site Oxygen Injection Remedial System National Grid Corporation Project No. 061140-14-2309 Date: Time: Weather: Inside Trailer Temperature: Performed By: O 2 Generator (AirSep AS-E PSA) Compressor (Kaesar Rotary Screw) Hours Compressor Tank * (psi) Feed Air Pressure * (psi) (readings below are made from control panel) Delivery Air (psi) Cycle Pressure * (psi) Element Outlet Temperature ( o F) Dewpoint Oxygen Receiver Pressure * Running Hours (hours) (psi) Loading Hours (hours) Oxygen Receiver Tank Pressure Motor Starts (reading from blue tank) Regular Hours (hours) (psi) Maximum Pressure (psi) Oxygen Purity (percent) * maximum reading during loading cycle * maximum reading during loading cycle Injection Bank 1 Injection Bank 2 Injection Bank 3 Depth scfh psi Depth scfh psi Depth scfh psi Point 1 - Point 9 - Point 17 - Point 2 - Point 10 - Point 18 - Point 3 - Point 11 - Point 19 - Point 4 - Point 12 - Point 20 - Point 5 - Point 13 - Point 21 - Point 6 - Point 14 - Point 122 - Point 7 - Point 15 - Point 23 - Point 8 - Point 16 - Point 24 - Comments: Page 1 of 3 H:\WPROC\Project\KEYSPAN\Halesite\OMM Plan\Final 050609\ Generic Monthly System O&M Log.xls

Date: OXYGEN INJECTION OPERATION AND MAINTENANCE LOG Injection Bank 4 Injection Bank 5 Injection Bank 6 Depth scfh psi Depth scfh psi Depth scfh psi Point 25 - Point 33 - Point 41 - Point 26 - Point 34 - Point 42 - Point 27 - Point 35 - Point 43 - Point 28 - Point 36 - Point 44 - Point 29 - Point 37 - Point 45 - Point 30 - Point 38 - Point 46 - Point 31 - Point 39 - Point 47 - Point 32 - Point 40 - Point 48 - Comments: OPERATIONAL NOTES GA5 Air Compressor 1) Oil Level Checked with system unloaded* Yes No * Unload system, wait until Delivery Air Pressure is less than 9 psi 2) Oil Level with system unloaded Low (red) Normal (green) High (orange) 3) Oil added Yes No 4) Oil changed Yes No 5) Oil filter changed Yes No 6) Air filter Changed Yes No 7) Oil separator changed Yes No 8) Terminal strips checked Yes No AS-80 O 2 Generator 1) Prefilter changed Yes No 2) Coalescing changed Yes No Page 2 of 3 H:\WPROC\Project\KEYSPAN\Halesite\OMM Plan\Final 050609\ Generic Monthly System O&M Log.xls

Date: OXYGEN INJECTION OPERATION AND MAINTENANCE LOG Halesite Former MGP Site GENERAL SYSTEM NOTES Trailer 1) Performed general housekeeping (i.e. sweep, collect trash inside and out, etc.) Yes No 2) Abnormal conditions observed (e.g. vandalism) 3) Other major activities completed 4) Supplies needed 5) Visitors Record routine activities such as any alarm/shutdowns, sampling, maintenance, material transported off-site, oil/filter/gasket and/or any other abnormal operating conditions: Action Items Page 3 of 3 H:\WPROC\Project\KEYSPAN\Halesite\OMM Plan\Final 050609\ Generic Monthly System O&M Log.xls