EXECUTIVE OFFICER'S REPORT- March 2001

SOUTH BASIN

Concentrated Animal Feeding Operations (CAFO) - Joe Koutsky

The U.S. Environmental Protection Agency (EPA) is proposing strict new controls to reduce the amount of surface water pollution from large livestock operations. The new requirements would apply to as many as 39,000 CAFOs across the country at estimated annual compliance costs to each CAFO operator ranging between $24,000 and $36,000. There are approximately 15 dairies and an unknown number of poultry or other CAFOs within the Region.

A CAFO is currently defined as having 1,000 or more cattle or comparable "animal units" of other livestock. Smaller operations may also be CAFOs if they are a threat to water quality. The proposal EPA is considering would require operations with 300 to 1,000 cattle to have a permit if certain risk-based criteria are met.

In addition to stricter permitting requirements, the proposal includes several new strict controls: 1) eliminates potential exemptions from permits presently used in some states; as a result, EPA expects that all large livestock operations will now have to acquire permits; 2) EPA and the states will issue co-permits for corporations and contract growers to ensure financial resources exist to meet environmental requirements; and 3) the spreading of manure on the land owned by livestock facilities would be limited to protect water ways.
George Air Force Base (AFB) Federal Fiscal Year 2002 Project Peer Review - Jehiel Cass

The Air Force has developed a project list for federal FY 2002 that was evaluated by a "peer review" team comprised of a ranking officer, civilian personnel and academic professors to ensure that proposed projects have technical merit before they are funded. Regulators from the Regional Board and
U.S. EPA participated in a February 2001 George AFB peer review meeting in Sacramento.

The peer review team concluded that some of the proposed groundwater investigation and cleanup projects had merit but expressed concern on the lack of an overall cleanup strategy to address regulatory concerns. For example, it was clear to the peer review team that efforts currently underway to calibrate computer ground water models should be stopped until the location of earthquake faults are understood. A detailed written list of recommendations will be provided to George AFB including a recommendation to form a "blue-ribbon" panel to develop a comprehensive cleanup strategy for George AFB before any new specific projects are approved. The regulatory remedial project managers support this conclusion and will continue to participate in the peer review process.
Dieldrin Investigation in Ground Water beneath Former George Air Force Base - Patrice Copeland

Dieldrin has been detected in ground water at George Air Force Base (GAFB) at concentrations that exceed the California Department of Health Services, Action Level for toxicity (0.002 micrograms per liter [mg/L]) since 1994. Although no primary or secondary State or Federal maximum contaminant level has been established for dieldrin, it has been identified as a carcinogen. Dieldrin is a pesticide that was widely used during the 1950s to the early 1970s. Dieldrin has been used to combat insects such as termites, for soil and seed treatment, and in public health to control disease vectors such as mosquitoes. No source of dieldrin has yet been identified.

Regional Board staff requested a Preliminary Assessment/Site Investigation to determine the source of dieldrin in the ground water. Ground water investigation was performed during 2000 that analyzed for dieldrin in four existing upgradient monitoring wells and one water supply well. No Dieldrin was found in these wells. However, Dieldrin continues to be detected at trace concentrations in at least four monitoring wells. Board staff is working with the Air Force to ensure that dieldrin investigations continue to be a priority for the Air Force. The Air Force has planned additional soil and ground water investigations for dieldrin, pending the outcome of a recently completed peer review to approve federal fiscal year 2002 projects.
Furnace Creek - Michele Ochs

The National Park Service (NPS) is examining water supply alternatives in the Furnace Creek area of Death Valley National Park. An EIS is being prepared. Recently, public scoping meetings were held in Pahrump Nevada, and in Furnace Creek and Independence, California. The EIS is expected to be complete in 2002.

In the Furnace Creek area, Texas Spring, Travertine Springs, and Furnace Creek supply water to a water treatment plant for treatment and public supply. The springs and creek have provided public supply water to the area since before the 1900's. The current treatment plant, built in 1974, disinfects the water with chlorine. Recent analytical reports noted the presence of E. Coli in the waters of Texas Spring, which led to that system being taken off line. There are no sewer or septic systems upgradient from Texas Spring. The problem has been attributed to a rodent population residing in the weeds and palms around the spring. National Park Service maintenance personnel are removing the weeds and doing some housekeeping to remedy the problem.
Waste Management of California, Inc. -Antelope Valley Public Landfill I and II - Greg Cash

Waste Management of California Inc. proposes to combine two landfills in the Palmdale area (Antelope Valley Landfill I and Antelope Valley Landfill II) into one landfill, thereby having only one Waste Discharge Requirement (WDR). Antelope Valley Landfill I is an active landfill, and Antelope Valley Landfill II has not been constructed yet. The new landfill expansion will have to meet Title 27 Regulations. The Discharger has applied for a Conditional Use Permit (CUP), and the Los Angeles County Department of Regional Planning is reviewing the CUP at this date.

Certain issues have arisen during the CUP permitting process, which include:
- Steep Cut Slopes along the northern boundary of the landfill, requiring complex engineering design to stabilize the upper slopes of the existing landfill, prior to installation of the prescriptive liner system;
- Annexation of the Antelope Valley Landfill II (Los Angeles County) into the City of Palmdale, where the Antelope Valley Landfill I is located;
- Discovery of Indian artifacts in the expansion area, which include fire pits and related Indian artifacts;
- California Environmental Quality Act issues that might indicate that the project will have adverse effects on cultural and paleontological resources;
- Close proximity to the San Andreas Fault Zone; and
- Relocation of major transmission electrical lines that occur between the two landfills
After acceptance of the CUP, the Discharger will submit a Joint Technical Document to the regulatory agencies for approval. Revised WDRs for this facility will be necessary and will be brought before the Regional Board in the future
IMC Chemicals, Trona - Michele Ochs

Compliance with Board Orders
As required in Cease and Desist Order (CDO) No. 6-00-61 and Cleanup and Abatement Order (CAO) No. 6-00-64, Board staff continues to receive weekly reports from IMC Chemicals (IMCC). IMCC has been meeting the interim effluent limits set forth in their WDRs with only one exception since the first of the year. Although the CAO required IMCC to eliminate all visible hydrocarbons from the surface waters of Searles Lake by January 30, 2001, a sheen of hydrocarbons on surface waters is still being reported daily. IMCC has reduced the amount of oil discharged and is continuing with cleanup of floating oil and with measures to prevent bird contact with oil. IMCC has requested an extension to the CAO deadline to allow time to implement more long-term cleanup plans and Board staff recommends the extension be granted.

Beneficial Uses
IMCC personnel, their consultants, and Board staff have agreed to an approach to gather the necessary information of support site-specific beneficial use designation for certain effluent-dominated surface waters of Searles Lake. Regional Board staff is also coordinating these efforts with the Department of Fish and Game (DFG). Sampling by IMCC to determine surface water quality variability in coordination with Regional Board and DFG staff will occur this month. These meetings will be a forum to discuss issues, resolve problems, and expedite compliance. Some of the meetings are planned to be technical reviews of methods for achieving compliance, while others will focus on basin planning issues.

Mitigation
The work continues on the pilot restoration pond that is being built by IMCC under the direction of Department of Fish and Game. However, progress has been slowed by recent rains. Only one bird death has been reported since the first of the year. The drop in bird deaths is contributed to three factors; 1) non-peak migratory season, 2) rescue efforts of International Bird Rescue Research Center, and 3) discouraging waterfowl by using noise cannons, birds of prey calls, motor boats, netting, and Mylar ribbons.
Sampling for Chromium VI at Edwards Air Force Base - Elizabeth Lafferty

Edwards Air Force Base (Base) has sampled all of its drinking water wells for Chromium VI in January 2001.

The Base sampled the potable water production wells and detected Chromium VI at concentrations ranging from non-detect to 9.3 parts per-billion (ppb). The uniformity of the concentrations and the lack of other contaminants over such a wide spread area, leads to the conclusion that these concentrations probably represent naturally occurring chromium. The potable water wells in Los Angeles County, in the Antelope Valley had a similar range of Chromium VI concentrations. As a matter of comparison, the well that provides water to the west side of Lancaster reportedly contains 14 ppb Chromium VI.

It is commonly believed that metal plating, corrosive inhibitors and aircraft paint-using facilities are usually the source of Chromium VI. However the presence of the constituent at a relatively low, uniform concentration throughout the valley may indicate that Chromium VI occurs naturally.

Molycorp, North Tailings Pond (P-16) - Curt Shifrer

Molycorp is currently installing a 40-mil polyvinyl chloride liner on a portion of the existing tailings surface within P-16. The liner installation is part of Molycorp's Interim Plan for P-16. Under the Interim Plan, Molycorp will resume mining and discharge of tailings to the lined area, while it completes permitting and construction for a new long-term tailings disposal facility. P-16 would not be used for tailings disposal after November 1, 2002.

The Regional Board adopted Revised Waste Discharge Requirements (Revised WDRs) for Molycorp's Interim Plan at its November 2000 meeting in Ridgecrest. The Executive Officer issued an Amended Cleanup and Abatement Order (Amended CAO) requiring Molycorp to improve capture of P-16 leakage by the existing Ground Water Corrective Action System and a Shallow Leakage Interception System (Systems). Current leakage is from dewatering through tailings settlement and drainage of free liquid from tailings. To comply with the Amended CAO, Molycorp has recently installed two additional extraction wells to improve the Systems. Molycorp disposes of captured leakage by evaporators located on P-16. Molycorp expects to start mining and discharge tailings to the lined portion of P-16 within the next few months.
Status of Mojave River Floodplain Aquifer Sampling and Analysis Program, Mojave Watershed - Mike Plaziak

The sixth round of water quality sampling was initiated under the Mojave River Floodplain Aquifer Sampling and Analysis Program (SAP) during March 2001. The objectives of the SAP are to assess surface and ground water quality in the Mojave River between Afton Canyon and the Mojave Forks Dam. Current water quality objectives for the Mojave River will be evaluated and updated based on the findings of the study. The SAP was developed by Board staff and Stakeholders in 1999 through the Watershed Management Initiative and includes water quality monitoring from four surface locations and 22 ground water monitoring wells completed in the shallow water bearing zone of the floodplain aquifer. The eighth and final sampling event is scheduled for the third quarter 2001. Board staff will compile the water quality data and issue a report during the fall of 2001.

NORTH BASIN
Tahoe Basin Interagency Road Runoff Collection and Treatment Subcommittee (TIRS) - Mary Fiore-Wagner

The Tahoe Basin Interagency Road Runoff Collection and Treatment Subcommittee (TIRS) complete a Best Management Practices (BMP) Guidance Manual (Manual). The focus of the group is to identify the most effective BMPs and design standards to minimize the impacts resulting from road operations. The Manual is intended for road and highway departments and other entities implementing stormwater treatment projects in the Lake Tahoe Basin. The Manual focuses on source control, stormwater conveyance, treatment, maintenance, and BMP effectiveness monitoring. To help project proponents understand the permitting needs associated with project implementation, the Manual includes a permitting chapter which outlines both TRPA and LRWQCB's permitting processes. A draft version of the Manual was circulated for review and comment. Comments were received from TRPA, California Tahoe Conservancy, USFS, USEPA, Placer County, Caltrans, NDOT, and the LRWQCB. Regional Board staff is in the process of incorporating the comments received into a revised draft that will again be circulated for review and comment. TIRS anticipates that the Final Manual will be ready for publication by September 2001.
Tahoe Turfgrass Management Workshop, Tahoe Basin - Bruce Warden

On March 28, 2001 the Regional Board will host a workshop on Tahoe Turfgrass Management at the Kahle Community Center from 8:00 am to 12:20 pm. We are inviting golf course supervisors, professional landscapers, garden nurseries, owners, city parks and recreation department staff, environmental organizations, and any person or agency with concerns about water quality aspects of turfgrass management. Topics of the workshop include biological and non-biological control of turfgrass pests and diseases, basics of water quality protection, environmentally sound fertilizer management, and irrigation management using state-of-the-art satellite technology for evapotranspiration estimation and water application. The speakers are professionals with Cooperative Extension and Department of Agriculture. The purpose of the workshop is to assist managers of turfgrass in the environmentally sensitive Lake Tahoe Basin to develop and implement methods for pest, fertilizer, and irrigation management to protect water quality. In particular, this workshop will assist California-side Lake Tahoe golf course supervisors to improve their chemical and irrigation management plans required under Waste Discharge Requirements of the Regional Board.

The five California golf courses in the Tahoe Basin-Bijou Golf Course, Lake Tahoe Golf Course, Old Brockway Golf Course, Tahoe City Golf Course, and Tahoe Paradise Golf Course, have been under Waste Discharge Requirements (WDR) including a monitoring and reporting (M&R) program since 1989. These requirements were updated in June of 2000.

The updated WDR requires development of a chemical and irrigation management plan for each golf course. The plan is to consider the following at a minimum:
- fertilizers and pesticides amount, timing, method, and frequency;
- irrigation system efficiency, scheduling, soil moisture measurement and root zone water holding capacity, and evapotranspiration rates;
- soil nutrient testing; and
- plant tissue testing
The primary objective of this workshop is to assist golf course supervisors in development of chemical and irrigation management plans that provides for efficient and environmentally effective turfgrass management by providing expert input for these and other technical topics. We are also using this opportunity to educate landscape professionals and citizens in environmentally responsible and resource efficient management of turfgrass in the Lake Tahoe Basin.
Meeting to Discuss Implementation of SB 1522-Recycled Water Use to Protect the Luther Pass Pump Station - Erika Lovejoy

Staff held a meeting on March 7th to discuss implementation of SB 1522, emergency legislation allowing the use of recycled water to protect the Luther Pass Pump Station in the event of a catastrophic fire. Representatives from the United States Forest Service (USFS), Lake Valley Fire District (LVFD), El Dorado County Public Health (EDCPH), Tahoe Regional Planning Agency (TRPA), South Lake Tahoe Public Utilities District (STPUD), and the surrounding neighborhood participated in the meeting.

STPUD will be placing six fire hydrants along Grass Lake Road, off of Highway 89. The hydrants will utilize recycled water from an existing pipeline. The Upper Truckee River, plus some small drainages are located very nearby the fire hydrants. Several houses are also located throughout the area. Installation of the fire hydrants is scheduled for July this year.

A number of safety measures were identified to protect both environmental and human health, such as additional hydrant valves and clear signage. STPUD will be providing more detailed information on environmental impacts for regulator agency review. Specific regulatory requirements will be determined after that time.
Proposed Memorandum of Understanding with U.S. Forest Service, Zaca Mine/Colorado Hill mining area, Alpine County - Jason Churchill

The Colorado Hill mining area in Alpine County, encompassing a number of abandoned mine sites including the Zaca Mine, is currently being assessed by the United States Forest Service (USFS) prior to anticipated cleanup efforts under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). The area is situated on USFS lands, and drains to Monitor Creek, a tributary of the East Fork Carson River. Monitor Creek is listed on the Clean Water Act Section 303(d)-list as an impaired waterbody due to metals contamination. Metals-laden acid mine drainage discharges from a number of mine portals and seeps in the area. Numerous waste rock and tailings piles at the site may also be a potential environmental concern. USFS staff has agreed to work with Regional Board staff in developing a proposed Memorandum of Understanding (MOU), to foster a cooperative approach between the two agencies and guide cleanup efforts. A cooperative approach guided by an MOU may be preferable to enforcement action by the Regional Board, provided that the MOU enables the Board to ensure that water quality problems at the Colorado Hill site are effectively abated within a reasonable timeframe.

The USFS has also prepared a draft Preliminary Assessment (PA) and a draft Sampling and Analysis Plan for the Colorado Hill site, which are currently being reviewed by Board staff. The purpose of the PA is to assemble and evaluate existing data in order to characterize the site and determine the threat to humans and the environment. The draft PA describes the site and its history, and presents data defining the quality of surface waters and defining the metals and mineralogical content of various mining waste piles. The data are compared to a variety of risk assessment criteria. The Sampling and Analysis Plan calls for extensive monitoring of metals and other parameters in Monitor Creek and in discharges from a number of mine portals. The first round of sampling is scheduled for March 27, 2001. The USFS expects to complete a Site Investigation/Engineering Evaluation-Cost Analysis by December 2001 that will recommend remedial measures based on an evaluation of alternative approaches.
Truckee River Aquatic Monitors - Jill Wilson

The Truckee River Aquatic Monitors (TRAM) has been chosen to represent citizen involvement in California's TMDL process. During February the iTV film crew, under contract with the State Water Resources Control Board, filmed a few select citizens' groups throughout the state of California. This is the same film crew that produced last year's storm water show.

TRAM is a local citizen's group that monitor's stream health of the Truckee River watershed from the outlet of Lake Tahoe to the California border. The group uses benthic macroinvertebrates as indicators of water quality. TRAM volunteers collect important baseline data on selected streams throughout the watershed and also monitor long-term trends.

We can thank a 319(h) grant for starting this successful group. Regional Board staff has provided important logistical and technical support to TRAM since the group's inception 2 years ago. TRAM's role in citizen monitoring continues to grow. More and more community groups are approaching TRAM to ask for assistance. TRAM has joined the Truckee River Habitat Restoration Group as part of a current Prop 13 proposal for watershed analysis. TRAM also recently received a 319(h) grant in partnership with the Truckee River Habitat Restoration Group and Truckee River Days. The group will be monitoring the success of certain Truckee River Days restoration projects, as well as continue with baseline data collection within the Truckee River watershed. The information collected by the group can establish a baseline to compare future conditions with and provide data to the TMDL program.

While in Truckee, the film crew took shots of TRAM volunteers collecting organisms from the Truckee River and identifying the aquatic insects in the lab. Lahontan Regional Board staff gave interviews on non-point source issues affecting the Truckee River and the importance of citizen monitoring to the TMDL effort. Watch for this program to be aired nationally this fall on CNBC.
Update on Squaw Valley Public Service District, Water Supply Well No. 3 and the Opera House UST Diesel Contamination, Placer County - Tammy Lundquist

On March 6, 2001 Squaw Valley Ski Corporation (Ski Corp) installed a mid-level groundwater monitoring well to check potential migration of a diesel contamination plume into a deeper zone. The potential for diesel migration into the deeper zone concerns Staff because the Squaw Valley Public Services District (SVPSD) Supply Well No. 3 is screened in the deeper zone. SVPSD has not operated Well No. 3 since October 1998 after the diesel contamination was first discovered in the shallow portions of the groundwater.

The new mid-level monitoring well (MW-9) is screened from 50 to 60 feet below surface grade, which is above SVPSD Well No. 3's screened intake zone. Board staff is awaiting the analytical results from the soil and groundwater samples to evaluate whether or not the diesel plume has migrated into the deeper zone. Staff will review the analytical results and will determine if subsequent corrective actions are needed.
Spalding Community Service District - Scott Ferguson

The Spalding Community Service District (District) serves a small community (Spalding Tract subdivision) located on the west shore of Eagle Lake in Lassen County. The Spalding Tract subdivision is one of two subdivisions in the Eagle Lake Basin where the Regional Board adopted waste discharge prohibitions against wastewater discharges from septic tank/leachfield systems. The other community is the Stones-Bengard subdivision, which currently has a community wastewater system consisting of evaporation ponds.

Wastewater disposal in the Spalding Tract subdivision is to individual septic tank/leachfield systems. The property owners are currently under cease and desist orders issued by the Regional Board in response to the continued use of the septic tank/leachfield systems, which violates the Regional Board's waste discharge prohibitions. The District has been making steady progress towards developing a community wastewater collection and treatment system that will comply with Regional Board regulations.

The District is currently completing the environmental review process, involving both CEQA and NEPA (USFS currently owns the parcel where the wastewater facilities will be located). After completing the environmental review process (anticipated completion March/April 2001), the District will be in a position to continue pursuing a State Revolving Fund loan. SWRCB staff has approved the Draft Revenue Program which will allow the District to obtain a design grant of approximately $500,000 this year. The District anticipates breaking ground on the wastewater treatment facilities during the 2002 construction season.

Once the wastewater facilities are constructed, Spalding Tract residents will be required to discontinue use of and render their septic tank/leachfield systems inoperable and connect to the wastewater facilities. Residents will also have the option of having alternative wastewater systems, provided they comply with the Regional Board's, Lassen County's, and the District's regulations. Board staff is hopeful that Spalding Tract residents will be cooperative in complying with the Regional Board's regulations once the community wastewater facilities are operational. Enforcement action will be proposed for residents who continue to violate the Regional Board's regulations once the community wastewater system is operational.
Water Quality Assessment/Section 303(d) List Update - Judith Unsicker

The federal Clean Water Act requires states to report every two years to the U.S. Environmental Protection Agency on the quality of their surface waters (Section 305[b]) and to update their lists of impaired water bodies requiring Total Maximum Daily Loads (Section 303[d]). The deadline for the next Section 305(b)/303(d) reporting cycle is April 1, 2002. The State Board has requested that Regional Boards solicit information for update of the Section 303(d) list from the public, and use this information as the basis for recommendations to the State Board for changes (additions and/or deletions) to the list. In March, Regional Board staff formally began the process by sending a letter soliciting information to several hundred addresses including a water quality assessment mailing list, and the agenda announcement mailing list. A press release on the information gathering process was sent to the media regionwide, and a notice about the process was published in representative newspapers. The press release and solicitation letter were placed on the Regional Board's public webpage. The letter requests that information be submitted by May 15, 2001.

Our staff report, with draft recommendations for changes in the Section 303(d) list, and in priorities and schedules for developing TMDLs, will be released for public review during the summer of 2001. Public workshops or hearings are tentatively planned for the Board's September and October meetings to allow public comments on the draft recommendations. At the October meeting the Board will be asked to approve a resolution transmitting recommendations to the State Board. The State Board will conduct its own public participation process before adopting changes to the statewide Section 303(d) list for transmission to the Environmental Protection Agency.
Sierra Pines Mobile Home Park Septic System, Alpine County - Bud Amorfini

Regional Board staff was recently notified of a chronic problem with sewage overflows at the Sierra Pines Mobile Home Park (MHP) in Woodfords. There are approximately 30 mobile home units at the Park and complaints from some of the residents have escalated to the Regional Board staff, other state agencies, and the local press because the MHP owner and Alpine County Health Department (County Health) have been unable to resolve the problem to date. In addition to incidents of surfacing sewage effluent, residents have reported that gray water hookups have been disconnected on occasion at several trailer spaces and that the MHP owner has pumped raw sewage from septic tanks the to ground when performing system repairs or maintenance. Residents are concerned that the MHP owner has not properly disinfected areas where spills have occurred and that the condition may contaminate the MHP's water supply.

Our staff met with County Health representatives, the facility owner, and complainants on February 27, 2001 to assist with resolving the problems. County Health and Regional Board staff directed the owner to design and install a replacement system, prepare an interim management plan to address potential future overflows, and cease intentional discharges of sewage to surface soils. County Health staff is requiring the owner to have a qualified engineer evaluate the site and design a replacement system by July 2001, and have the system installed by September 2001. Regional Board staff ascertained that the water supply is not threatened and believe that appropriate action is being taken by County Health to rectify the problem. Staff will continue to monitor County Health's progress in implementing applicable Basin Plan requirements under the Memorandum of Understanding between the Regional Board and County Health.
Herlong Utilities Cooperative - T. Jerrold Peacock

A new Federal Correctional Institution (Prison) is proposed on lands on and adjacent to the U.S. Army Sierra Army Depot in Herlong which have been offered to Lassen County as a result of the Base Realignment and Closure Act of 1995 (BRAC). This will include a medium-security Prison, a minimum-security Prison Camp, and auxiliary facilities to serve the various components of the facility. An EIR for this project was adopted in late 2000. A separate Herlong Utilities Cooperative has been formed to construct and operate water and sewer collection, treatment and disposal systems to serve this additional growth in the Herlong area.

Staff will prepare new waste discharge requirements (WDR's) for the wastewater treatment facilities.

Lassen County is preparing a CEQA document for the project's water supply and sewage collection and treatment facility. It is anticipated these facilities will also serve portions of the remaining Sierra Army Depot, and some of the existing facilities will be abandoned. Regional Board staff has met with project consultants to outline probable WDR's.
Regional Board's Remediation Efforts at the Beacon Gas Station in Meyers - Douglas F. Smith

The Regional Board has been conducting investigation and cleanup activities at this leaking underground storage tank site since July 1998 due to recalcitrance by the owner and operator to conduct the needed work. The Regional Board's cleanup efforts are funded by the Emergency, Abandoned, and Recalcitrant (EAR) Account of the State Water Resources Control Board. Methyl tertiary-butyl ether (MTBE) from the gas station impacted two municipal drinking water wells owned by South Tahoe Public Utility District (STPUD), and the wells were subsequently destroyed by the District.

During the Fall of 2000, the Regional Board's consultant, SECOR International, commenced an additional groundwater investigation by installing five wells on site and 35 wells off site in the surrounding neighborhood to define the lateral and vertical extent of contamination. Subsequent water quality monitoring through March 8, 2001 indicates that low levels of MTBE have migrated at least 2,200 feet downgradient from the gas station site. Of the forty wells installed and sampled, only six water samples showed results for MTBE.

Most water samples did not show any contaminants during the six months of sampling that took place between October 2000 and March 2001. The average MTBE concentrations in the plume range from either "non-detect" to just slightly above the secondary Maximum Contaminant Level of 5 parts per billion. A pump-and-treat remediation system continues to operate and remove contaminants from groundwater beneath the site.

Because the concentrations of MTBE and other contaminants are consistently either not detected or at very low-levels, I anticipate bringing this item to the Board meeting for discussion about the appropriate cleanup levels for the site.