Chapter 11 Federal Efforts To Prevent Groundwater

Chapter 11

Federal Efforts To PreventGroundwater Contamination

Contents

Page

Chapter Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215

Prevention of Contamination by Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215Scope of the Groundwater Resource Addressed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215Types of Programs and Sources Addressed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223Performance Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Aquifer Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

Regulating the Production and Use of Potential Contaminants. . . . . . . . . . . . . . . . . . . 226Toxic Substances Control Act . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226Federal Insecticide, Fungicide, and Rodenticide Act . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228

Chapter 11 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

TABLETable No. Page

40. Federal Provisions To Prevent Groundwater Contamination From Sources . . . . . . . . . 218

Chapter 11

Federal Efforts To PreventGroundwater Contamination

CHAPTER OVERVIEW

Activities authorized by Federal statutes relatedto the prevention of groundwater contamination arcdescribed in this chapter. They address preventionin terms of:

● s o u r c e s o f c o n t a m i n a t i o n ;

● groundwatcr recharge areas; and● potential contaminants.

The Federal Government does not have a for-mal plan or cornprehensive strategy to prevent con-tamination. For cxample, programs for sources—

for design and operation, siting, and post-closure—do not use a consistent definition of the ground-water resource to be protected and do not sys-tematically address the contamination potential ofsources. The program for protecting recharge areasis not comprehensive because the designation ofsuch areas is optional and only certain potential}’contaminating projects are restricted. To date, theapplication of provisions that regulate the produc-tion and use of potential groundwater contaminantsto prevent contamination has been limited.

PREVENTION OF CONTAMINATION BY SOURCES

Federal statutes and programs address preven-tion of conntamination from sources in terms of threetypes of factors:

1. the scope of the groundwater resource covered(e. g., groundwatcr in general or drinkingwater supplies);

2. the specific’ sources addressed and the type ofprogram (e. g., for design and operation—these may be either mandator}’ or voluntary);a n d

3. the performance requirements specified (e. g.,for the siting of’ sources and their closure).

Table 40 summarizes the provisions of Federal pro-grams in terms of’ these factors. Federal monitor-ing and corrective action requirements are notedin the table but they are discussed in chapters 6 and9. respectively.

1 F( JU r statutes Included I n [h. 3 are not applicable [(J [his discus-~it)n and [hus are not Included in table 40: NEP.4 and WRDA don( J[ (Jitdbl ish rcqu i mments for SOLI rces; C ERC 1..4 and the Reclama-t Ion A( t ( RA) are not in{ Iuded because they provide for remedial ac-t I(]ni, not pretentlte measures

Scope of the GroundwaterResource Addressed

The scope of groundwater resources covered byFederal programs is an important consideration inpreventing groundwater contamination. However,Federal programs are not consistent in defining theresource covered and the extent of degradation per-mitted. Table 40 (column 3) summarizes the wayin which groundwater is addressed by Federalprograms:

● The scope of groundwater resources coveredby Federal programs is not consistent.—Four programs (authorized by AEA for low-

level waste sites, FLPMA and associatedmining laws, SMCRA, and TSCA) addressgroundwater in general.

—Two programs are concerned with the up-permost aquifer (authorized by RCRA-Subtitle C and UMTRCA).

—Three programs cover underground drink-ing water supplies (authorized by RCRA-Subtitle D, SDWA, and CWA-Section405).

215

Table 40.-Federal Provisions To Prevent Groundwater Contamination From Sources

Type ofPublication program and

date ofCorrective

Relationship sources SitingStatute

Monitoring action Post-closureregulations to groundwater addressed requirements requirements b requirements requirements

Atomic Energy NRC regulations Radioactive material re-Act (10 CFR 61)–12/27/82 leased into ground-

(EPA has not promul- water must not exceedgated environmental levels specified in the-. -.--.: -- ---- 4 -.4-,plulcwtlul I ala Iualua) I“cyuiiliicn”ls

NRC proposed regula- Geologic repositoriestions (10 CFR 60)– include the operations718181, 46 FR 35280 area and the geologic

EPA proposed environ- setting (the geologic,mental protection stand- hvdrologic. and geo-ards (40 CFR 191)-12/29/82, 47 FR 58196d

Clean Water Act— Section 201 EPA Criteria—2/n/76,

41 FR 6190 (EPA con-struction grant regula-tions are specified in40 CFR 35)

chemical system-s thatprovide isolation of thewaste).

Groundwater is separatedinto three categoriesconcerning the landapplication of waste-water.— If groundwater is a

potential drinkingwater supply, theNational InterimDrinking WaterRegulations (NIDWRs)must not be ex-ceeded. If back-ground levels arehigher than NIDWRs,they must not beexceeded.

Design and operatingstandards are specifiedfor low-level wastedisposal sites.

Design and operatingstandards are spe-cified for geologic re-positories for high-levelradioactive wastes.

Disposal sites must pro-vide sufficient depth tothe water table to pre-vent groundwater in-trusion into me wastes.

Hydrogeologic units usedfor disposal shall notdischarge groundwaterto the surface withinthe disposal site.

Other requirementsrelate to seismic andother tectonicactivity, flooding, loca-tion of naturalresources, and popula-tion growth anddevelopment.

The geologic settingmust exhibit structural,tectonic, hydrogeologic,geochemical, and geo-morphic stability.Groundwater traveltimes (prior to wastedeposition) throughthe geologic setting(i.e., the area thatprovides isolation ofwastes) to the acces-sible environmentmust be at least1,000 years.

Criteria for best practicable Nonewaste treatmenttechnology for landapplication of waste-water must be met byapplicants for con-struction grant funds(for sewage treatmentworks).

Yes Yes Active institu-tional controls(e.g., monitor-ing) may notbe relied onfor more than100 years(the exactperiod to bedeterminedby the NRCon a case-by-casebasis).

Yes None Disposal sys-tems must bedesigned toprevent re-leases ofspecificamounts ofradioactivematerial for10,000 yearsafter disposal.Active institu-tional controlsmust not berelied onbeyond a fewhundred years.

Yes Yes None

Table 40.-Federal Provisions To Prevent Groundwater Contamination From Sources— continued


date ofCorrective

Relationship sources SitingStatute

Monitoring act ion Post-closureregulations to groundwater addressed requirements requirements requirements requirements

Clean Water Act — If groundwater is used– Section 201

(cent’d)as a drinking watersupply, the conditionsabove must be met(except that levelsfor biological con-taminants must notbe exceeded in thesupply if water isnot disinfected).

— If groundwater isused for purposesother than drinkingwater, criteria areestablished on acase-by-case basis.

– Section 208 EPA State grant regula- The program is orientedtions (40 CFR 35, Sub- to surface water; how-part G)–5/23/79 ever, States are au-

thorized to undertakegroundwater activitiesto the extent prac-ticable.

— Section 311 EPA regulations The program is oriented(40 CFR 112)–12/11/73 to surface water pro-

tection; groundwateris not directlyaddressed.

– Section 404 EPA regulations Protection is oriented to(40 CFR 230)–12/24/80 wetlands protection;

groundwater is notdirectly addressed.

None None None None

Funds are authorized for Not Not Not NotStates to develop water applicable applicable applicable applicablequality managementplans. State plans pro-vide for developmentof activities (e.g., BestManagement Practices)related to certainnon-point sources.e

Spill Prevention andCountermeasure Control(SPCC) Plans must beprepared for above--ground and undergroundtanks of a specifiedsize containing oil.The plan must describedesign and operatingconditions.

Permits must be obtained General guidance is pro- Noneto dispose of dredged vialed that relatesor fill material. Guide- to the selection of dis-Iines to be applied in posal sites such thatthe review of proposed the potential for erosion,discharges are specified. slumping, or /caching

of material into sur-rounding aquatic eco-systems will bereduced.

None None


Type ofPublication

date ofprogram and Corrective

Relationship sources Siting Monitoring action Post-closureStatute regulations to groundwater addresseda requirements requirements requirements requirements

– Section 405

Coastal ZoneManagementAct

EPA Criteria(40 CFR 257)-9/13/79

NOAA State grantregulations(15 CFR 923)–3/28/79

Federal Insecticide,Fungicide, andRodenticide Actf

– Section 3 EPA regulations(40 CFR 162)–7/3/75

— Section 19 EPA regulations(40 CFR 165)–5/1/74

Federal LandPolicy andManagement Act

— Mineral Leasing BLM regulationsAct of 1920 and (43 CFR 23)–1/18/69Materials Actof 1947

Criteria for determiningunreasonable adverseeffects do not explic-itly address ground-water.

Regulations refer towater systems; ground-water is not explicitlyaddressed.

The use of pesticidesthat may cause un-reasonable adverse ef-fects on the environ-ment can be restrictedor prohibited.

Recommended proce-dures are establishedfor storage areas forpesticides.

Regulations specify that Requirements for mininga plan of operations of leasable minerals onmust be developed that Federal lands areincludes measures to to be specified in theprevent or control plan of operations.groundwater pollution.State and Federal waterquality standards mustbe met.

None

Notapplicable

Use restrictions maybe established for apesticide.

Facilities should belocated where floodingis unlikely and wheresoil and hydrogeologiccharacteristics willprevent contaminationof any water systemby runoff or perco-lation.

Operations may be pro-hibited or restricted inareas if the regulatoryauthority determinesthat water qualitywill be loweredbelow State standardsor levels set by DOI.Groundwater isnot explicitlymentioned.

Yes Yes None

Not Not Notapplicable applicable applicable

None None

None None

None

None

None None Performancebond must befiled to coverreclamationactivities.

w

●

Table 40.—Federal Provisions To Prevent Groundwater Contamination From Sources— continued

Type ofPublication program and Correct we

date of Relationship sources Sltinq Monitong action Post-closureStatute regulations to groundwater addressed requirements requirements requirements c requirements

— U.S. Mining BLM regulationsLaws (43 CFR 3800)–3/3/80

— Geothermal BLM regulationsSteam Act (30 CFR 270)–6/27/79

and 6/30/829

Hazardous Liquid DOT regulationsPipeline Safety (49 CFR 195)–7/27/81Act as amended

Hazardous DOT regulationsMaterials (49 CFR Subtitle B,Transportation Subchapter C)–4/15/76Act as amended

Resource Conserva-tion and RecoveryAct

– Subtitle C EPA regulations(40 CFR 264)–7/26/82Note: Final regulationshave not been promul-gated for coveredunderground tanks orfor some open burn-ing and detonationsites.

Groundwater is not di-rectly addressed in theregulations; however,State and Federal waterquality standards mustbe met.

Regulations specify thata plan of operationsmust be developedwhich includes meas-ures to prevent orcontrol groundwater pol-I u t i o n . S t a t e a n dFederal water qualitystandards must be met.

The objective of the reg-ulations is to preventleakage. However,groundwater isnot directlyaddressed.

The objective of theregulations is toprotect against risksto life and property.However, groundwateris not directlyaddressed.

Requirements for min- None None None Performanceing of locatable min- bond must beerals on Federal lands filed to coverare to be specified in reclamationthe plan of operations. activities.

Requirements for develop- Nonement of geothermalsteam on Federal landsare to be specified inthe plan of operations.

Des ign and ope ra t i ng Nonestandards are specifiedfor pipelines used totransport hazardousliquids.

Design and operatingstandards are specifiedfor transportation ofhazardous materialsand hazardous wastes.

None

Regulations specify that Design and operating Facilities must not behazardous substances standards are specified located in areas sub-entering groundwater for hazardous waste ject to flooding(in the uppermost treatment, storage, or seismic conditions.aquifer) must not ex- and disposal facilitiesceed background (e.g., landfills, surfacelevels, the Maximum impoundments, wasteContaminant Levels for piles, and land treat-14 constituents specified ment areas).by the National InterimDrinking Water Regula-tions (if higher thanbackground), or alterna-tive concentrationlimits (established ona case-by-case basis)at the compliance point.

Yes

None

None

Yes

None None

None None

None None

Yes Specifiedactivities(e.g., ground-water monitor-ing and op-eration ofIeachate col-lectionsystem) mustbe continuedfor 30 yearsafter closureunless thetime period isincreased oror decreasedby the regula-tory authority.


Type ofPublication program and Corrective

date of Relationship sources Siting MonitoringStatute

action Post-closureregulations to groundwater addressed a requirements requirements requirements requirements

– Subtitle D

Safe DrinkingWater Act -

– Part C(UIC Program)

Surface MiningControl and

EPA regulations(40 CFR 257)–9/13/79

EPA regulations(40 CFR 146)–6/24/80as amendedNote: Regulations havenot been promulgatedfor certain wells.1

OSM regulations(30 CFR 816 and 817)–

Reclamation Act revised 9126183(Regulations were firstpublished in 1979)

The criteria specify thatfor underground drink-ing water sources,background levels orthe National InterimDrinklng Water Regula-tions (if higher thanbackground) must notbe exceeded beyondthe application bound-ary or an alternativeboundary establishedon a case-by-case basis.

Regulations specify thatit must be demonstratedthat activities will notbe conducted in amanner that allowsmovement of contam-inants into an under-ground sourceof drinkingwater (defined as anaquifer or its portionthat supplies anypublic water systemor contains sufficientwater to supply apublic water systemand that currentlyserves as a drinkingwater supply orcontains fewer thanI0,000mg/1 TDS).Aquifers may be ex-empted if they arenot currently drinkingwater supplies, cannotand will not be sup-plies in the future, orcontain 3,000-10,000mg/1 TDS and are notreasonably expectedto supply a publicwater system.

Regulations specify thatgroundwater qualitymust be protected byhandling earth materialsand runoff in a mannerthat minimizes acidic.

Funds are authorized forStates to developoptional State solidwaste programs.Specified Federalcriteria for sanitarylandfills must be metby State program.

Design and operatingstandards are specifiedfor underground injec-tion wells.

Requirements are speci-fied in operating permitfor surface coal min-ing and undergroundcoal mining (forsurface effects).

None None None None

None

None

Yes

Yes Yes

None None h

Performancebond must befiled to coverreclamationactivities.



date ofStatute

Relationship sourcesregulations to groundwater addressed

Toxic SubstancesControl Actf

— Section 6

Uranium MillTailingsRadiationControl Act

EPA regulations(40 CFR 761)–5/31/79

NRC regulations(10 CFR 40)–10/3/60

EPA regulations(40 CFR 192)–10/7/83,48 FR 45926

toxic, or other harmfulinfiltration to ground-water systems and bymanaging excavationsand other disturbancesto prevent and controlthe discharge of pol-lutants into ground-water. State andFederal water qualitystandards must bemet.

The objective of regula-tions is to ensureagainst an unreason-able risk of injury tohealth or the environ-ment (e.g., water) fromthe manufacture, proc-essing, distribution,use, or disposal of achemical substance ormixture.

Same as RCRA–Subtitle C (except thatlevels for certainradioactivesubstances arespecified).

Design and operatingstandards are specifiedfor PCB disposal sites.

Design and operatingstandards arespecified for uraniummill tailings disposalsites (same as RCRASubtitle C require-ments for surface im-poundments).

CorrectiveSiting Monitoring action Post-closure

requirements requirements requirements requirements

Facilities must be locatedin areas of low to mod-erate relief and mustavoid floodplains, shore-Iands, and groundwaterrecharge areas.

Bottom of landfill mustbe 50 feet fromhistorical high watertable.

NRC requirementsspecify that the selec-tion process mustconsider hydrologicand other conditionsas they contribute tocontinued immobiliza-tion and isolation ofcontaminants fromusable groundwatersources.

EPA regulations do notestablish siting re-quirements.

Yes None Operatingrecords mustbe retainedfor 20 yearsafter closure.

Yes Yes Long-termsurveillance isspecified byNRC on acase-by-casebasis.

EPA regulationsrequire thatsites bedeveloped tobe effectivefor 1,000 yearsto the extentreasonableachievableand in anycase for atleast 200years.

asee table 13 and app, H for additional information on sources, types of programs, and design and operating requirements.

%ee table 30 and app. E for additional information on monltonng requirements.csee table 36 and app. G for additional information on correctwe action Pmw.ions%he provisions cited in the table are EPA’s proposed protection standards.eprovisions aPPIY t. non.point sources Including irrigation return flows, agricultural sources, Iwestock areas, mine rUnOff, saltwater Intrusion, and construction actlvltYf See the text for a more detailed discussion of FIFRA and TSCA.gRegulatlons for the Geothermal Steam Act were redesignated, with minor revisions, as 43 CFR 3260 on Sept. 30, 1983.~here are plugging requirements at closure.I Regulations have not been promulgated for Class IV and V wells under the UIC Program; see app. H and 40 CFR 146.

SOURCE: Office of Technology Assessment

222 ● Protecting the Nation’s Groundwater From Contamination

–One program (under Section 201 of CWA)separates groundwater into three catego-ries—drinking water supplies, potentialdrinking water supplies, and groundwaterused for other purposes—with differentstandards for each category.

—The programs authorized by five statutesdo not directly address groundwater in anyway (CWA—Sections 311 and 404, CZMA,FIFRA, HLPSA, and HMTA).

—The requirements for selecting geologic re-positories for high-level radioactive wastes(under AEA) include surrounding hydro-geologic systems as part of the repository.

● The extent of degradation permitted by Fed-eral programs is not consistent.—Under the Subtitle C program of the Re-

source Conservation and Recovery Act(RCRA, which addresses the uppermost

aquifer), the Environmental ProtectionAgency (EPA) may establish alternativeconcentration limits on a case-by-case basis(instead of requiring that groundwater con-tamination not exceed background levels orMaximum Contaminant Levels). EPA reg-ulations specify the factors that must be con-sidered in approving the alternative concen-tration limits.2 However, decisions are to bemade by permit writers on a site-specificbasis.

—Under the Underground Injection ControlProgram of the Safe Drinking Water Act(SDWA), certain aquifers maybe exempted.Thus, underground injection into thoseaquifers is not controlled.

‘See 40 CFR 264.94(b).

Photo credit: CECOS International

Liners and Ieachate control systems are included in the design and operating requirements for hazardous waste landfillsand surface impoundments under Subtitle C of RCRA. This photograph shows a synthetic and clay-lined hazardous waste

disposal facility prior to use.

Ch. n-Federal Efforts To Prevent Groundwater Contamination . 223

Types of Programs andSources Addressed

The principal type of program related to the pre-vention of contamination from sources is for de-sign and operation. As indicated in chapter 2, po-tential sources of contamination have differentcharacteristics for releasing substances (e. g., pointv, non-point discharges) which necessitate differentdesign specifications and operating procedures toprevent groundwater contamination, Programsmay be either mandatory or voluntary; and theyare specified for particular sources of contamina-tion. Design and operating requirements are sum-marized in table 40 (column 4) and described indetail in appendix H in relation to each Federal pro-gram and OTA source categories (refer to ch. 2,table 5). The following observations can be madeabout the types of programs that have been devel-oped. (Note that the technical adequacy of theseprograms has not been evaluated in this study. )

● Mandatory design and operation requirementsapply to subsets of sources within CategoriesI, II, III, and V. As noted in chapter 3, thesources addressed by programs with manda-tory requirements are, for the most part, asso-ciated with hazardous wastes or other toxicmaterials.

● With the exception of certain mining activi-ties and the application of certain pesticides,sources in Category IV are not subject to man-datory requirements. However, Best Manage-ment Practices or recommended procedureshave been developed for some of these sources.

● There are no mandatory requirements for anysources in Category VI.

It is significant that many of the programs’ re-quirements were established fairly recently. Table40 (column 2) indicates that the majority of regu-lations were published within the past 5 years.Thus, the impacts of some of these programs onthe prevention of groundwater contamination can-not yet be ascertained. Further, despite the fact thatprograms have been authorized by Federal legis-lation for certain sources, regulations specifyingdesign and operating (as well as monitoring andcorrective action) requirements have not been pro-

mulgated for certain sources. These sourcesinclude:

. covered underground tanks (under RCRA);

. injection wells used to dispose of hazardouswastes into or above underground sources ofdrinking water and all other injection wells ex-cept those used for the following purposes: dis-posal of hazardous or radioactive materials andother wastes (e. g., municipal or industrial) be-neath underground sources of drinking water;wells used in association with oil and gas pro-duction; and wells used for in-situ or solutionmining (under SDWA);

. open burning and detonation sites (underRCRA); and

● low-level radioactive disposal sites (underAEA) .3

In addition, the purview of the Hazardous Liq-uid Pipeline Safety Act (HLPSA), which establishesrequirements for interstate pipelines (used to trans-port petroleum products and anhydrous ammonia),includes the storage of liquids incidental to theirmovement by pipeline. Although regulations havebeen promulgated for pipelines, the Departmentof Transportation has not established requirementsfor storage facilities (e. g., tanks).

Performance Requirements

This study also examined the extent to whichFederal programs address the prevention of ground-water contamination with performance require-ments for siting new sources and post-closure. Asindicated in table 40 (column 5), siting provisionsfor new sources are specified by six programs: high-and low-level radioactive waste programs under theAtomic Energy Act (AEA); pesticide storage pro-visions under the Federal Insecticide, Fungicide,and Rodenticide Act (FIFRA); mineral mining pro-visions for leasable minerals under the MineralLeasing Act; the hazardous waste program (Sub-title C) under RCRA; the PCB disposal require-ments under the Toxic Substances Control Act(TSCA); and the Nuclear Regulatory Commission

3The Nuclear Regulatory Commission has issued licensing regula-tions for these facilities. However, EPA has not issued environmentalprotection standards.

224 ● Protecting the /Vation’s Groundwater From Contamination

Photo credits: U.S. Environmental Protection Agency

Open burning and detonation of waste explosives are addressed under RCRA but regulations have not yet been promulgated.These photographs show white phosphorus drums being prepared for disposal . . . and their subsequent detonation.

requirements for uranium mill tailings sites estab-lished under the Uranium Mill Tailings RadiationControl Act (UMTRCA). Of the six programs, therequirements established under RCRA and theMineral Leasing Act do not explicitly address theprotection of areas vulnerable to groundwater con-lamination. 4

Provisions that address any contamination thatmay occur after a source is no longer in use (’‘post-closure’ are also important for the prevention ofcontamination. Table 40 (column 8) summarizesthese provisions .5 Post-closure provisions are speci-fied for a limited number of sources: disposal fa-cilities for hazardous and certain radioactivesubstances and mining operations. There is alsoan inconsistency between the requirements for haz-ardous waste facilities and high-level radioactivewaste sites: in spite of the fact that many of thechemicals found in hazardous waste disposal facil-ities are non-degradable, a post-closure period of

only 30 years has been set. G In comparison, it hasbeen proposed that high-level radioactive wastedisposal sites which contain radioactive substancesthat do degrade over time (e. g., half-lives ofradioactive substances range from tens to more thanmillions of years) must be designed to prevent re-leases for 10,000 years.7

There are two additional points about the post-closure requirements in table 40 with respect to spe-cific

1.

2.

sources:

There are no post-closure monitoring re-quirements established for PCB disposal fa-cilities. Thus, any groundwater contamina-tion that may occur following closure is notlikely to be detected.Specific requirements have not been estab-lished for uranium mill tailings sites. Post-closure provisions will be required only at thediscretion of the regulatory authority.

4Proposed RCRA regulati >ns issued by EPA on Dec. 18, 1978 (43FR 59000) did contain siting requirements with respect to aquiferrecharge areas, but the provi iions were not adopted in the final regu-lations issued by the agency (40 CFR 264. 18).

‘In this assessment, reclamation activities conducted as part of min-ing operations are considered post-closure provisions.

‘Although the post-closure period can be extended by the regula-tory authority if necessary, it is possible that a site will appear to besecure at the end of the 30-year period but subsequently releasesubstances into groundwater.

747 FR 58196, Dec. 29, 1982.

Ch. 1 l—Federal Efforts To Prevent Groundwater Contamination ● 225

AQUIFER PROTECTION

A second approach of Federal statutes related tothe prevention of groundwater contamination is toprotect recharge areas. The Sole Source Aquiferprovision of the Safe Drinking Water Act, Section1424(e), allows the Administrator of EPA to desig-nate the aquifers that serve as sole or principaldrinking water sources and to prevent any commit-ments of Federal financial assistance to projects thatmay create significant hazards to public health bycontaminating such aquifers.

The Sole Source Aquifer provision ’does not es-tablish a comprehensive program for protectingaquifer recharge areas. The process for designat-ing sole source aquifers is optional, and only cer-tain projects are restricted from receiving Federalfinancial assistance. In addition, funding decisionsare based on findings regarding the significance ofthe hazard posed to human health.8

EPA issued proposed regulations in September1977 establishing procedures for designating solesource aquifers and reviewing projects proposed inthese areas (final regulations have not been pub-lished by EPA).9 The proposed regulations defineseveral key terms used in this section of the statute:

● A sole or principal source aquifer is definedas one which supplies 50 percent or more ofthe drinking water for an area. The proposedregulations also specify six factors that mustbe considered in deciding whether to designatea sole source aquifer:1.

2.

3.

4.5.

6 .

the availability of alternative sources ofdrinking water;the size of the area and population servedby the aquifer;the susceptibility of the aquifer to con-tamination through the recharge zone;the location of the aquifer;the number of public water systems usingwater from the aquifer, the number of peo-ple served by the systems, and the treatmentprovided by the systems; andsuch other factors as are deemed relevant.10

●

●

A significant hazard to public health meansany level of a contaminant: a) which causesor may cause the aquifer to exceed any Max-imum Contaminant Level set forth in any pro-mulgated National Primary Drinking WaterRegulation at any point where the water maybe used for drinking purposes or which mayotherwise adversely affect human health, orb) which may require a public water systemto install additional treatment to prevent suchadverse effects.Federal financial assistance includes any finan-cial benefits provided directly as aid to a proj-ect by a department, agency, or instrumental-ity of the Federal Government in any form,including contracts, grants, and loan guaran-tees. Actions or programs carried out by theFederal Government itself (e.g., dredging per-formed by the Army Corps of Engineers) andactions performed for the Federal Governmentby contractors (e. g., construction of roads onFederal lands) are not included. Federal finan-cial assistance is limited to benefits earmarkedfor a specific program or action and awardeddirectly to the program or action .11

As of July 1984, EPA had designated 17 sole sourceaquifers (see EPA, 1983, 1984).

1145 FR 5 I fjz 1. EPA has indicated that it ‘‘will not be concernedwith reviewing on an individual basis, small isolated commitmentsof financial assistance such as individual home mortgage loans.

12De~ignated aquifers are:1. Edwards Aquifer, TX (petition received 1 /3/75, designated

12/16/75)2. Nassau/Suffolk Counties Long Island, NY (petition received

1/21/75, designated 6/21178)3. Maryland Piedmont (petition received 10/1/75, designated

8/27180)4. Northern Guam (petition received 11/20/75, designated 4/26/78)5. Fresno County, CA (petition received 8/9/76, designated

9/10/79)6. Spokane-Rathdrum Prairie, WA-ID (petition received 10/4/76,

designated 2/9/78)7. Biscayne Aquifer, FL (petition received 5/8/78, designated

10/1 1/79)8. Buried Valley, NJ (petition received 1/16/79, designated 5/8/80)9 Cape Cod, MA (petition received 3/4/81, designated 7/31/82)

10. Whidbey Islandj-WA (petition received 4/31~81, designated—8The Sole Source Aquifer provision originated as a floor amend-

ment to the Safe Drinking Water Act. See Hemphill, 1976.’42 FR 51620, Sept. 29, 1977.1042 FR 51623.

4/6/82)11. Camon Island, WA (petition received 4/31/81, designated

4/6/81)12, Kings/Queens Counties, NY (designated 1/24/84)


After an area is designated as having a sole orprincipal source aquifer, the Regional Adminis-trator may review any project located in that areafor which Federal financial assistance is proposed.The proposed regulations specify the review pro-cedures that must be followed by EPA. Anyone

(footnote 12 continued)13. Ridgewood, NJ (desi\:nated 1/24/84)14. Upper Rockaway River Basin, NJ (designated 1/24/84)15. Upper Santa Cruz and Avra-Altar Basin, AZ (designated

1/24/84)16. Nantucket Island, MI\ (designated 1/24/84)17. Block Island, RI (ales gnated 1/24/84)ljIf an area is designated, ~pA must identify the boundaries of the

recharge zone or streamflow !iource zone (or portions thereo~ through

may petition EPA to review a project, or EPA mayinitiate the review. In addition, Federal agenciesare required to maintain a list of projects in therecharge or streamflow zone of a designated aquiferfor which environmental impact statements (underthe National Environmental Policy Act, NEPA) willbe prepared. EPA has stated that “the process ofproject review pursuant to Section 1424(e) will beintegrated as fully as possible with the review ofFederal actions subject to NEPA."14

which contamination could affect the area and the water bcdy or bodieswhich contact the recharge zone. 42 FR 51623.

‘+42 FR 51621.

REGULATING THE PRODUCTION AND USEOF POTENTIAL CONTAMINANTS

There are two Federal statutes that providefor regulation of the production and use of poten-tial groundwater contaminants: the Toxic Sub-stances Control Act and the Federal Insecticide,Fungicide, and Rodenticide Act, Both require sub-mission of data on the environmental effects ofchemicals and authorize the regulation of poten-tial groundwater contaminants. To date, however,their use for the prevention of contamination hasbeen limited.

Toxic Substances Control Act

The Toxic Substances Control Act (TSCA) pro-vides for the regulation of chemical substances andmixtures whose manufacture, processing, distribu-tion in commerce, use or disposal may present anunreasonable risk of Injury to health or the envi-ronment, 15 Unlike other statutes analyzed in thisstudy (e. g., RCRA and SDWA), TSCA does notfocus on specific sources of groundwater contamina-tion. However, because it encompasses all aspectsof a chemical’s pathway through society, includinguse and disposal, TSC A has the potential for direct-ly addressing groundwater contamination (see ch.

1’” ‘Environment’ is defined to include water, air, and land andthe interrelationship which exists among and between these media andall living things (Section 3(5)). ‘‘Groundwater’ is not explicitly men-tioned.

2 for a discussion of pathways). In addition, TSCAprovides a mechanism for obtaining data on theproperties of certain chemicals associated withsources of groundwater contamination.

Two provisions of TSCA are most relevant tothe prevention of contamination.

1.

2.

Section 5 requires that manufacturers or im-porters of ‘new’ chemicals submit a preman-ufacture notice (PMN) to EPA 90 days beforethe substance enters commerce. The PMN isto include sufficient data for EPA to determinewhether the manufacture, processing, distri-bution in commerce, use, or disposal of thenew chemical—or any combination of suchactivities—will present an unreasonable riskof injury to health or the environment.16

Section 6 provides for regulation of the man-ufacture, ‘processing, distribution in com-merce, use, or disposal of chemical substancesor mixtures that present or will present an un-

16TSCA does not define ‘ ‘unreasonable risk. In 1979, EPA statedthat it “intends to balance the magnitude of risks and social benefitsassociated with a chemical substance. In doing this, EPA will con-sider the seriousness of the risk (including the nature, extent, and re-versibility of the adverse effects), the availability of alternatives to thesubstance and their associated risks, and the benefits (economic andotherwise) which accrue to society from the production and use of thesubstance. 44 FR 16243, Mar. 16, 1979.

Ch. Ii—federal Efforts To Prevent Groundwater Contamination . 227

reasonable risk of injury to health or the envi-ronment. 17

Section 5. TSCA specifies that the PMN sub-m it ted to EPA by a manufacturer must include in-formation regarding the chemistry of the newsubstance, proposed uses, the amounts to be man-ufactured or processed, the byproducts, the num -ber of’ workers to be exposed and the duration ofexposure, and methods of disposal. General classesof information are also to be submitted to EPA,inclucl ing any available test data in the possessionor control of the manufacturer related to environ-mental and health effects and a description of anyother data, insofar as known to the manufactureror reasonably ascertainable.18 EPA can then takeone of four actions following the review of a PM N’:1 ) allow the substance to be manufactured with-out restriction; 2) allow the substance to be manu-factured for specified uses (EPA would have to benotified about other uses); 3) if a decision aboutunreasonable risk cannot be reached because of thelack of’ in information, delay the manufacture, proc-essing, distribution, use, or disposal until additionalinformation is developed; or 4) regulate the man-u facture, processing, distribution, use, or disposalof t the substance.

A previous OTA study reviewed the informa-tion contained in the 740 PMNs submitted to EPAfrom July 1, 1979 to June 1981 and in June 1982(0TA, 1980). The study found that 62 percent ofthe PMNs reported all the information specified byTSCA (e. g., chemistry, proposed uses, amounts,byproducts, exposure, and disposal methods).However, only 10 percent of the PMNs reportedany information from tests used to estimate envi-ronrnental effects. Physical-chemical data mostdirectly related to predicting the behavior of chem-icals in groundwater- density, vapor pressure,solubility (in water), and partition coefficient-werereported, respectively, on 19 percent, 24 percent,

1 T@her Sec.[ions of TSCA provide for: the compilation of an in-~’ento~ of existing chemicals manufactured or processed in the UnitedStates and the recording and reporting of certain health and environ-mental data (Section 8); the development of test rules on health andenvironmental effects of existing chemicals (Section 4); the commence-ment of ci~il actions when chemical substances pose an imminenthazard (Section 7); and the authorization of State grants for estab-lishment and operation of programs to prevent or eliminateunreasonable risks (Section 28).

18 Sect~on 5(d)(l).

42 percent, and 4 percent of all PMNs (OTA, 1983;Gough, 1983), In addition, although approximately50 percent reported toxicity information, only 17percent had any test information about the 1ikeli-hood that the chemical could cause cancers, birthdefects, or mutations.

In the absence of data on the physical-chemicalproperties of chemicals used to assess environmentaleffects under the PMN review process, EPA relieson estimates of chemical properties and the use ofcomputer models to determine whether the use ofa new chemical may affect groundwater. 9

Section 6. This section provides EPA with broadauthority to address sources of groundwater con-tamination directly by regulating the use or disposalof a chemical substance or mixture .20 To date, EPA

19EpAs office of Toxic Substances has undertaken two projectsto support the premanufacture review process. One involves a com-puter program, CHEMEST, which estimates certain chemical prop-erties on the basis of molecular structure information (Arthur D Lit-tle, 1983). The program is capable of providing estimates of thefollowing properties: volubility in water; the soil adsorption coefficient;bioaccumulation or the bioconcentration factor (in fish); the activitycoefficient; the boiling point; the vapor pressure; the rate of volatiliza-tion from water; and Henry’s Law Constant.

The second project involves the development of two models usedto assess the behavior of a chemicat in soil and groundwater. One mmielpredicts movement through the unsaturated zone (Bonazountas, etal. , 198 1), and the other simulates the transport of contaminantsthrough an aquifer (Yeh, 1981). Information compiled on 70 loca-tions in the United States is the data base for these computer model-ing efforts (Versar, 1983).

Zosect ion 6 requires the Administrator of EPA to take one or moreof the following actions if there is a reasonable basis to conclude thatthe manufacture, processing, distribution in commerce, use, or disposalof a chemical substance or mixture (or any combination of activities)presents or will present an unreasonable risk of injury to health orthe environment:

1.

2.

3.

4.

.5.

6.

7.

prohibit or limit the amount of such substance or mixture whichcan be manufactured, processed, or distributed;prohibit or limit the amount of such substance or mixture whichcan be manufactured, processed, or distributed for a particularuse or a particular use in excess of a specified level;require that such substance or mixture be accompanied by clearand adequate warnings and instructions with respect to its use,distribution in commerce, and/or disposal;require manufacturers or processors of such substance or mix-ture to make and retain records of certain processes;prohibit or otherwise regulate any manner or method of com-mercial use of such substance or mixture;prohibit or otherwise regulate the manner or method of disposalof such substance or mixture provided that State (or other levelof government) laws or requirements are not violated, and re-quire notification of the appropriate level of government; anddirect manufacturers or processors of such substance or mixtureto give notice of such unreasonable risk of injury and replaceor repurchase such substance or mixture.

The factors which must be considered in promulgating a Section6 rule include:


has regulated four chemicals or groups of chemi-cals under Section 6 1 ) fully halogenated chloro-fluorocarbons, 2) waste materials containing tetra-chlorodibenzo-p-dioxin (TCDD), 3) asbestos, and4) polychlorinated biphenyls (PCBs) .2’ Only thePCB regulations involve disposal provisions relatedto preventing groundwater contamination. How-ever, one State in responding to OTA’s Statesurvey noted that the PCB disposal regulations arenot being strictly enforced by EPA and that TSCAdoes not provide for the transfer of regulatoryauthority to the States. The TCDD requirementsprohibit the disposal of wastes containing TCDDby a particular chemical company (which is undercourt order to undertake remedial actions at a haz-ardous waste site under RCRA); the company isrequired to store and monitor the wastes until along-term solution is found.

Federal Insecticide, Fungicide,and Rodenticide Act

The overall thrust of the Federal Insecticide,Fungicide, and Rodenticide Act (FIFRA), whichregulates pesticides in the United States, is to en-sure that the use of a pesticide will not cause un-reasonable adverse effects on the environment. 22FIFRA defines an unreasonable adverse effect onthe environment as ‘‘any unreasonable risk to manor the environment, taking into account the eco-nomic, social and environrmental costs and benefitsof the use of any pesticide. FIFRA contains two

A.

B.

c.

D.

the effects of such substance or mixture on health and the mag-nitude of the exposure of human beings to such substance ormixture;the effects of such substance or mixture on the environmentand the magnitude of the expc)sure on the environment to suchsubstance or mixture;the benefits of such substance or mixture for various uses andthe availability of subs itutes for such uses; andthe reasonably ascertain,ible economic consequences of the rule,after consideration of the effect on the national economy, smallbusiness, technological ilmovation, the environment, and publichealth (Section 6(c)(l)).

Zlsee 40 CFR 762, 40 CFR 775, 40 CFR 763, and 40 CFR 761,respectively. Procedures for ndemaking under Section 6 are speci-fied in 40 CFR 750. Congress explicitly directed EPA to promulgatedisposal and labeling requiren-ents for PCBS within 6 months of theeffective date of TSCA and to phase out their use over a 2-year period;the PCB disposal requirements established by EPA with respect tomonitoring, correction actions, and design and operation are discussedin chs. 6, 9, and 11, respecti~ ely.

Zzsee Section 2(bb). Like TS(3A, FIFRA does not explicitly includegroundwater in the definition of environment.

principal provisions relevant to the prevention ofgroundwater contamination: 1) Section 3 providesfor the registration of all pesticides based on thesubmission of data specified by EPA and for theclassification of pesticides for general or restricteduse; and 2) Section 6 authorizes EPA to suspendand cancel the registrations of pesticides that causeunreasonable adverse effects on the environment. 23

Section 3. Section 3 of FIFRA requires theregistration of all pesticides. In addition to regis-tering new pesticides, EPA is also mandated to re-view all existing registrations to ensure that theymeet current requirements, 24 There are 40,000pesticides (containing some 1,400 active ingredientsin 578 generic categories) now registered by EPA.

For a pesticide to be registered, FIFRA requiresdeterminations including that it will function as in-tended without unreasonable adverse effects on theenvironment, and when used in accordance withwidespread and commonly recognized practice, itwill not generally cause unreasonable adverse ef-fects on the environment.25

EPA issued final regulations establishing basicregistration requirements in July 1975.26 Thepesticide registration regulations enumerate threerisk criteria for EPA use in determining whethera pesticide causes an unreasonable adverse effect:1) acute toxicity in humans, other mammals, orbirds, 2) chronic toxicity in humans, test animals,or endangered species, or population reductions innon-target organisms, and 3) lack of emergencytreatment for ameliorating the toxic effects of apesticide in people.27 The regulations did not iden-

Zsother sections of FIFRA authorize EPA to: certify pesticide ap-plicators to ensure that they are competent with respect to the use andhandling of restricted pesticides (Section 4); establish procedures andregulations for the disposal or storage of packages and containers ofpesticides or excess amounts of pesticides (Section 19); formulate aNational Monitoring Plan (Section 20); and authorize certain Stateresponsibilities (Sections 24 and 26).

ZfThe 1972 amendments to FIFRA established the re-registrationrequirement. Subsequent amendments have attempted to streamlinethe re-registration process by authorizing EPA to develop generic stand-ards for pesticide ingredients. These standards are used to review bothnew and existing registrations of individual products containing thoseingredients. As of April 1984, EPA had issued 75 generic standards.Anticipating that generic standards are needed for 400-500 catego-ries of pesticides, EPA is currently developing such standards at a rateof 25 per year (Auerbach, 1984).

25 Section 3(c)(5).m40 CFR 162, Subpart A.v40 CFR 162.1 l(a)(3).

Ch. 1 I—Federal Efforts To Prevent Groundwater Contamination • 229

F’hoto credit: State of F/orida Department of .Environrnenta/ Regulation

Pesticides may be introduced into groundwater from non-point sources such as land application, as well as from point sourcesof hazardous wastes (e.g., landfills), non-hazardous wastes (e.g., residential disposal), and non-waste products (e.g., storage tanks).

tify’ the types of data needed to satisfy the statu-tory registration requirements. However, EPA de-\’eloped guidelines between 1975 and 1981describing such data requirements. In November1982, EPA proposed regulations that reorganizedthe guidelines and listed the specific types of dataand information needed to support a pesticideregistration. 28

Guidelines published by EPA as a companiondocument to the 1982 proposed regulations iden-tify the following characteristics of a pesticide asbeing most pertinent to an evaluation of its poten-tial to contaminate groundwater: leachability; ad-sorption/desorption characteristics; resistance tochemical, photochemical, and biological degrada-tion; volubility in water; and volatility (EPA,1982).29 For the assessment of these characteristics,

2847 FR 53192, No\.. 24, 1982.Zgq’hls FJpA document supports 40 C FR 158, Subdivision N, pro-

posed Data Requirements for the Registration of Pesticides, 47 CFR53192.

EPA’s proposed regulations require the submissionof data resulting from degradation, metabolism,mobility, dissipation, and accumulation studies.30

Section 3(d) of FIFRA requires EPA to classifypesticides (as part of the registration process) forgeneral or restricted use. A pesticide is classifiedfor restricted use:

. . . if, the Administrator determines that thepesticide, when applied in accordance with itsdirections for use, warnings and cautions and forthe uses for which it is registered, or for one or moreof such uses, or in accordance with a widespreadand commonly recognized practice, may generallycause, without additional regulatory restrictions,unreasonable adverse effects on the environment,including injury to the applicator. .. .31

3040 c FR 158, 130, 47 FR 53205. F.nvironmcnta] fate data re-quirements were issued as a public draft in 1978 and again in Oc-tober 1980; see 47 FR 53194 and EPA, 1982.

~lsection 3(d)(l)(C).

38-799 0 - 84 - 12 : QL 3

230 . Protecting the Nation’s Groundwater From Contamination

The statute provides I hat if a pesticide is classifiedfor restricted use on the basis of human healthhazards caused by acute dermal or inhalation tox-icity, the pesticide can be applied only by a cer-tified applicator. 32 If a pesticide is classified for re-stricted use because it may cause an unreasonableadverse effect on the environment, the Administra-tor of EPA must require that it be applied by a cer-tified applicator or be subject to such other restric-tions as may be provided by regulation.33

The regulations regarding restricted use classi-fications do not state the specific types of actionsthat could be included in the ‘‘other restrictions’category. 34 However, the legislative history ofFIFRA indicates that other restrictions might in-clude geographic controls over the use of a pesticide(Costello, 1983).35 The regulations do specify thata pesticide product classified for restricted use mustbear a label that contains the statements of the re-stricted use classification and directions for use;36

these label restrictions could be used to prohibit theuse of certain pesticides in specified areas (e. g.,recharge areas) or to specify application proceduresthat prevent ground water contamination (e. g.,limiting the amounts or the rate of application)(Severn, et al., 1983).37

sZS~CtiO~ s(d)(l)(c)(i). A Celtifiecl applicator must be comPetent in

the use and handling of pesticides. EPA regulations identify com-petency standards. They include a demonstration of practical knowl-edge with respect to the envil onmental effects of the use or misuseof pesticides. See 40 CFR 171.

Sssection 3(d)( 1 )( C)(Ii).S+see 40 CFR 162.30. The regulations indicate, however, that the

risk criteria specified by 40 CFR 162. 11(a)(3) are to be used in deter-mining whether the use of a xsticide should be restricted.

sSThe report of the Senate Committee on Agriculture and Forestryexplained that although a third type of classification (permit only) wasrejected, EPA was not constrained “from regulating the quantity tobe applied for a given use for i particular application to a particularcrop in a given area at a given time, from limiting the number of ap-plications, or from prohibiting the use thereof. . . ‘‘ (U.S. Senate,1972).

3640 CFR 162.30(q).srLabe] restrictions have be m imposed for the use of aldicarb On

Long Island, NY, in res~onst to a reauest from the manufacturer.

Section 6. This section of the act allows the EPAAdministrator to suspend and cancel the registra-tion or change the registration of a pesticide (e. g.,from general to restricted use). A suspension or-der may be issued by EPA if it is determined nec-essary for preventing an imminent hazard duringthe time required for cancellation or change inclassification proceedings .38

A pesticide registration can be canceled or itsclassification changed if the pesticide causesunreasonable adverse effects on the environmentwhen used in accordance with widespread and com-monly recognized practice or if its labeling or othermaterial required for submission to EPA does notappear to comply with the provisions of FIFRA.39

Although actions taken under Section 6 are basedon a finding of unreasonable risk to humans andthe environment (i. e., a determination that acutetoxicity or chronic toxicity exceed criteria or thatthere is no emergency treatment), information re-garding the potential of a pesticide to leach throughthe soil into groundwater can be factored intoEPA’s assessment of exposure to pesticides that domeet the risk criteria .40

Sasection 6(C){ 1 ). An imminent hazard is defined in FIFRA, in %C-tion 2(l), as ‘‘a situation which exists when the continued use of apesticide during the time required for a cancellation proceeding wouldbe likely to result in unreasonable adverse effects on the environmentor will involve unreasonable hazard to the survival of a species declaredendangered by the Secretary of the Interior under Public Law 91-135. ”

Sgsection 6(b)(1). pursuant to Section 6(a)(1) of FIFRA, a pesticideregistration shall also be canceled at the end of any 5-year period whichbegins on the date of its registration unless a continuation is requested.

+osee for example, 48 FR 46234, Oct. 11, 1983 (46238). It is alSOimportant to underscore the fact that a finding of unreasonable riskunder FIFRA involves a process that weighs health risks against thebenefits of continued use of the t)esticide.

Ch. Ii—federal Efforts To Prevent Groundwater Contamination ● 231

CHAPTER 11 REFERENCESArthur D. Little, Inc., “User’s Guide, CHEMEST, A

Program for Chemical Property Estimation, pre-pared for U.S. Environmental Protection Agencyand the U.S. Army Medical Bioengineering Re-search and Development Laboratory, revised March1983.

Auerbach, J., Office of Pesticides and Programs, U.S.Environmental Protection Agency, personal commu-nication, Apr. 19, 1984.

Bonazountas, M., and J. M. Wagner, ‘‘SESOIL—ASeasonal Soil Compartment Model, ” Arthur D. Lit-de, Inc. (Washington, DC: Office of Toxic Sub-stances, U.S. Environmental Protection Agency,contract No. 68-01-6271, 1981).

Costello, G., “Groundwater Contamination ThroughApplication of Pesticides: Existing Federal Con-trols , Congressional Research Service, Jan. 21,1983.

Gough, M., Senior Associate, Office of TechnologyAssessment, Testimony before the Subcommittee onToxic Substances and Environmental Oversight,Committee on Environment and Public Works, U.S.Senate, July 28, 1983.

Hemphill, J. B., ‘ ‘Section 1424(e) of the Safe DrinkingWater Act: An Effective Measure Against Ground-water Protection?’ Environmental Law Reporter6:50121, November 1976.

Office of Technology Assessment, The InformationContent of Premanufacture Notices, Background Pa-per (Washington, DC: U.S. Government PrintingOffice, OTA-H-BP- 17, April 1983).

Severn, D. J., C. K. Offutt, S. Z. Cohen, W. L. Bur-

nam, and G. J. Burin, ‘ ‘Assessment of GroundwaterContamination by Pesticides, ” Hazard EvaluationDivision, Office of Pesticide Programs, U.S. Envi-ronmental Protection Agency, June 7, 1983 (pre-pared for the FIFRA Scientific Advisory PanelMeeting, June 21-23, 1983, Arlington, VA).

U.S. Environmental Protection Agency, “PesticideAssessment Guidelines, Subdivision N, Chemistry:Environmental Fate, ” Environmental Fate Branch,Hazard Evaluation Division, Office of Pesticide Pro-grams, NTIS PB83- 153973, Oct. 18, 1982.

U.S. Environmental Protection Agency, “Status of theSole Source Aquifer Program, ” Office of DrinkingWater, July 6, 1983.

U.S. Environmental Protection Agency, ‘ ‘Sole SourceAquifer Designations to Date, ” Office of DrinkingWater, May 1, 1984.

U.S. Senate, 92d Cong., 2d sess., “Legislative Historyof the Federal Environmental Pesticide Control Actof 1972, Public Law 92-516, ’ Senate Report No.838, 1972.

Versar, Inc., “Acquisition of Climatological Data andSoil Data and Creation of SESOIL and TOX-SCREENParameter Data Files, ” prepared for U.S. Environ-mental Protection Agency, contract No. 68-01-6271,May 9, 1983.

Yeh, G. T., “Analytical Transient One-, Two-, andThree-Dimensional Simulation of Waste Transportin an Aquifer System, ORNL-5602, Oak RidgeNational Laboratory, Oak Ridge, TN, March 1981.

Documents

Chapter 11 Federal Efforts To Prevent Groundwater