X-/EPA United States Environmental Protection Agency Office of Solid Waste and Emergency Response DIRECTIVE NUMBER: 9283.1-1 TITLE: Recommendations for Ground Water Remediation at the Mi liereek, PA Site APPROVAL DATE: EFFECTIVE DATE: ORIGINATING OFFICE: g FINAL D DRAFT STATUS: REFERENCE (other documents): March 24, 1986 March 24, 1986 OSWER/OERR OSWER OSWER OSWER E DIRECTIVE DIRECTIVE D ------- &EPA United States Environmental Protection Agency Wasnmgton. DC 20460 OSWER Directive Initiation Request Originator Information Nam* of Contact P tr son Betsy Shaw Lead Office Q OERR D OSW D n n OUST OWP6 AA-OSWEB Mail Coda WH-548E Aooroveo interim Directive Numoer 9283.1-1 Teleonone Numoer 382-3204 for Review Signature of Office Director Oaie Tut* Recommendations for Ground Water Remediation at the Millcreek, PA Site Summary of Directive Presents overall approach to decision-making regarding ground water cleanup at Superfund sites under development by OERR. This strategy will be further refined in the forthcoming Ground Water Evaluation Manual scheduled for issuance in the summer of 1986. Type of Directive iMtnutl. falter Oirtctiv*. Announcement. fte.J Policy Directive Status D Draft ED Final l2SLNew LJ Revision Does trtis Directive Super s«M Previous Directives)? | | res M. No Does It Supoiarnem Previous Directive* s>> fj Yes jxj No *^* . .' . . , ., «..„•- -c "lv "~* If "Yes" to Eimer Quemton. What Directive (numtttr. triltl Review Plan G AA-OSWEA D OUST D OERR O OWPE D OSW U Regions D OECM O OGC D OPP6 This Request Meets OSWER Directives System Format Signature of Lead Office Directives Officer Signature o< OSWER Directives Officer I Date Date tO A. fnrrr, ------- 9283.1-1 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON. D.C. 20460 MAR 2 4 1986 OFFICE OF SOLID WASTE ANO EMtHGtNCY MEMORANDUM SUBJECT: Recommendations for Ground Water Remediation at the Millcreek. PA Site //^ £& FROM: J. Wrnston Porter Assistant Administrator TO: James Seif, Regional Administrator Region III This is in response to your January 17 memorandum in which you raised concerns about the national policy implications_on the ground water remediation proposed for the Millcrouk, PA site. The Office of Emergency and Remedial Response (OERR) is developing a strategy which will articulate the general framework in which we would like to soe ground water cleanup decisions made nationwide. To assist you in addressing the issues involved at the Millcreek site, wo are providing a preview of some of the key features of the forthcoming strategy below. GERR's Hazardous Site Concrol Division (liSCD) is leading the effort to develop a strategy for ground water cleanups at Superfund sites. HSCD is being assisted in this effort by a ground water work group/ comprised of representatives from all relevant Agency offices, which has boon uxploring a widu range of ground water issues since its formation last August. HSCD's and the work group's efforts ultimately will culminate in an overall guidance for Supurfund ground wutur cluunup.Si scheduled for issuance late this spring. The guidance will elaborate in detail on the general approach outlined below. Preview of Forthcoming Superfund Ground Water Strategy One of the premises of EPA's Ground Water Protection Strategy (August 1984) is that ground water should be protected for its highest beneficial use. Superfund's implementation of EPA's Ground Water Protection Strategy will s&ufc rapid clounups of all currant and potential drinking wutur (Class I, Class II A, and Class II B ground waters) where it is cost-effective. ------- 9283.1-1 -2- For ground water remedial actions, at least one alternative should be developed in the Feasibility.Study which would attain applicable or relevant and appropriate health standards for carcinogens where they are available or a 10~6 risk level for carcinogens without standards for current and potential exposure. This alternative should be designed to attain these levels within a short period of time (for example one to five • years) and should be used as a point of departure in analyzing a range of alternatives. A range of alternatives should be developed which would achieve risk levels within the 10~7 to 10~4 risk range, within a variety of timeframes, and through various remedial approaches (e.g., pumping and treating, plume containment, natural attenuation). The cost-effectiveness of all alternatives will be analyzed as reouired by statute and the National Contigency Plan (NCP), and as laid out in the Feasibility Study Guidance. The determination of the appropriate risk level and the timeframe for reaching it will be based on the class of the ground water and other appropriate factors. In many situations, the most important factors will include: o Site and ground water characteristics; o Cost, reliability, speed, and technical feasibility- of each alternative; o Effectiveness and reliability of institutional controls which might be used as part of a remedy; o Degree of risk reduction each alternative may obtain; o Puhlic acceptability of the options; o Anticipated future need for the ground water (e.g., timing and extent of need); o Ability to provide an alternative water supply; and o Environmental considerations including indirect public health consequences. These various factors will have different emphasis depending upon the characteristics or class of ground water. For Class I ground waters, which are special by virtue of being an irreplaceable source of drinking water or ecologically vital (i.e., having the characteristics of a Class I aquifer), the desire for rapid restoration will be given primary emphasis in the determination of cost-effectiveness. Also for Class I ground waters, emphasis should be qiven to achieving levels at the more protective end of the risk management range. ------- 9283.1-1 -3- When evaluating the cost-effectiveness of remedies for currently used (typically Class II A) ground waters, the following factors are important: the ability to provide an alternate water supply, the anticipated future need of the ground water, the cost of proposed response actions, and the effectiveness of institutional controls during ground water remediation, in addition to the desire for rapid restoration to the target risk range of 10~7 to 10~4. For aquifers with the characteristics of Class II B ground water, which may be used as drinking water some time in the future, the Superfund program is more willing to accept longer- term remedies and higher risk levels within the risk range. EPA is currently uncertain about the long-term effectiveness of institutional controls as a means of restricting ground water use. This posture stems from the Agency's limited experience with such controls and the current lack of criteria against which their effectiveness can be judged, as well as uncertainty o^er the ability of a PRP or state to maintain or continue extended response actions, and uncertainty regarding Superfund's ability to oversee and fund additional response actions in the future. As a result, the Superfund program generally does not encourage ground water remedies with long timeframes. EPA is establishing a workgroup to develop criteria for evaluating the effectiveness and appropriateness of institutional controls, and guidelines for their use. This effort will examine time- frames beyond a rapid restoration period over which institutional controls can be effective. The analysis of the cost-effectiveness of remedial ground water alternatives may determine that it is not possible to implement a remedy within the preferred timeframe or to attain a cleanuo taraet within the 10"^ to 10"^ risk range because of technical impracticality or Fund-balancing. The NCP provides exceptions to accommodate such circumstances. Source control measures need to be consistent with long-term ground water remedies. The cost-effectiveness of source control alternatives can be analyzed separately from the cost-effectiveness of ground water options, but the response goals of both operable units should be considered together in selecting the source control remedy. A range of source control actions should be considered: 1. Closure to prevent direct contact; 2. Measures necessary to meet short-term ground water objectives; and 3. Actions necessary to achieve long-term ground water aoals. • . ------- -4- 9283.1-1 In general, source control measures should facilitate the achievement of the long-term objectives and goals for the ground water. Site Description The Millcreek site is a 72 acre parcel of land which was used as a landfill from 1941 to 1981. The unpermitted landfill received trash, foundry sand, furnace slag, waste refuse, and an undetermined amount of bulked and drummed liauid hazardous wastes. Surface soils and sediments are contaminated with PCBs, PAHs, phthalates, volatile organics, copper, and lead. A contaminant plume exists. The main contaminant in the plume is vinyl chloride with 1,1-dichloroethane, 1,1-dichloroethene, 1,2-dichloroethene, trichloroethylene (TCE), 1,1,1-trichloroethane also present. Ground water flows northeast and discharges into Lake Erie. To date the plume has migrated 1000 feet from the site and is 5,500 feet from Lake Erie. Assuming effective source control action is taken, it would take approximately 125 years for the contaminants in the plume to reach the lake and for levels in the around water to naturally attenuate to health-based levels. The ground water downgradient of the Millcreek site probably has the characteristics of Class II B (potential use) around water, although there are public supply wells located 1600 - 2100 feet upgraclient of the site, a situation which could be viewed as a Class II A setting. Peqional Position on Millcreek Region III prepared a draft Record of Decision (ROD) in early December, 1985. Performance criteria for remedial activities addressing contaminated soils, sediments, and around water- were established using a health-based risk approach. The Region's preferred alternative consists of: o Grading, soil cover, revegetation; o Excavation of soils and sediments to protect ground water at a 10~^ risk level; o Consolidation of soils and sediments followed by construction of a RCRA cap; o Ground water pumping and treating to recommended cleanup levels (10~4 risk level). The capital cost r- the preferred remedy as outlined in the Feasibility Study is $14.8 million - $20.9 million of which $3.1 million is to pump and treat the ground water. Operation and maintenance costs cor the pump and treat system are estimated at $611,000/year for the first two years, and $187,000 annually for cap maintenance and ground water monitoring for years 3 - 30. ------- 9283.1-1 -5- The total cost range accounts for the uncertainty related to the amount of contaminated soil which needs to be consolidated under the cap. Position of Potentially Responsible Parties (PRPs) The PRPs have met with Region III representatives and have raised several concerns regarding the proposed remedy. The PRPs also sent a letter to the Administrator on January 10, 1986 requesting a meeting with him to discuss the policy implications of response actions proposed for the Millcreek site. The PRPs auestion the need for both active source control and ground water actions. The PRPs urge EPA to consider that there are/is: 1. No current users of the ground water downgradient from the site; 2. An abundance of high guality drinking water in the area from other sources; and 3. A willingness on the part of at least some local government officials to install institutional controls on ground water use in.the vicinity. The PRPs believe the Remedial Investigaton/Feasibility Study (RI/FS) prepared for the Millcreek site contains insufficient information to justify the Region's proposed remedy. In dis- cussions with you and your staff, the PRPs have indicated that they believe the contaminated plume should be allowed to naturally attenuate and permanent institutional controls should be established to prevent ground water use. Consistency of Proposed Millcreek Response Action with OERR's Ground Water Strategy Region III began their analysis of the cost-effectiveness of remedial alternatives for the Millcreek site by looking at remedies which could achieve a 10~^ risk level within a short period of time. The Region determined the 10~6 risk level to be desirable and theoretically attainable, but impracticable to measure because it would involve reducing levels of vinyl chloride (the major contaminant) to .015 ppb, well below its detection limit of 1 ppb. According to the proposed MCL for vinyl chloride, the risk level associated with 1 ppb is approxi- mately 7 x 10~5. Region III is recommending a one to two y-^ar program of active pumping and treatment to reduce vinyl chloride levels to the detection limit resulting in an overall risk level of 10~4 for all constituents in ground water. The Region expects the aauifer to reach the 10~*> risk level for all constituents as the contamination naturally attenuates after pumping and treating, although the detection limit for vinyl chloride will prevent the Region from measuring this further reduction in vinyl chloride concentrations. ------- 9283.1-1 -6- Reqion Ill's proposed ground water remedy for the Millcreek site is consistent with the Superfund ground water strategy under development. The Region has evaluated a number of alter- natives within the 10~7 to 10~4 risk range, including a 10~6 option, and has arrived at a remedy which will attain a target risk range rapidly, well within an acceptable period of time. We agree with your preference'for rapid restoration since the long-term remedy would take 125 years to complete by natural attenuat ion. Region III has done an analysis for source control and has determined that a 10~6 risk level will meet the long-term goals for ground water remediation at Millcreek. This also is consistent with the strategy under development. We hope this preview of the forthcoming Superfund ground water cleanup strategy assists you in preparing the final Record of Decision for the Millcreek site. OERR will be soliciting regional comments on subsequent drafts of the evolving strategy and will also call upon your assistance in reviewing the overall ground water guidance later in the spring. If you have any questions, please call Bill Hanson (FTS 382-2345) or Lisa Woodson (FTS 475-8246). ------- |