The Man-Made Environment: Groundwater In recent years, the need to protect groundwater has become a critical part of all new construction projects. This increasing emphasis is because of the rapidly growing use of groundwater as a source of drinking water. According to Briggs (1976), more than 97 percent of the world’s fluid fresh water is underground. Obviously, this amount of water is not all available as a source of future drinking water, but its magnitude defines underground water as a precious resource to be husbanded for future needs. The use of groundwater for all purposes in the United States was estimated by the U.S. Geological Survey (Salley, 1997) to be as shown in Exhibit 4 for the year 1995. In contrast to rapidly moving freshwater streams, underground water moves very slowly and does not have ready access to oxygen supplies. This means that contam- inated underground water tends to remain in that condition. The result all too often is the loss of a major source of water supply for public or industrial purposes. 8.1 REGULATORY BACKGROUND Recognizing the need to keep underground water from becoming contaminated, the U.S. Congress, the EPA, and a number of states have taken various protective actions. There are a number of different federal and state laws and regulations that are designed to protect groundwater. In contrast to other media, groundwater protection is a function of several laws. The most common ones place emphasis on three areas: • Contamination by buried hazardous wastes. • Maintenance of the purity of sole-source aquifers. • Underground injection of wastes. The first, contamination of groundwater by buried hazardous wastes, is regu- lated by RCRA, CERCLA, and the Safe Drinking Water Act, which are discussed elsewhere in this book. Of particular concern is the possible contamination of groundwater by leachates from landfills. Existing landfills are covered by RCRA and abandoned ones by CERCLA. Over the years, toxic chemicals have accumulated in landfills and are leaching into the nation’s groundwater supply. Existing landfills now 8 © 1999 by CRC Press LLC EXHIBIT 4 Preliminary Groundwater Withdrawals by Water-Use Category and State, 1995* Public Commer- Thermo- Supply Domestic cial Irrigation Livestock Industrial Mining Electric Total State Fresh Fresh Fresh Fresh Fresh Fresh Saline Fresh Saline Fresh Fresh Saline Alabama 253 62 4.9 51 22 34 0 4.0 9.1 6.0 436 9.1 Alaska 30 8.3 11 0.1 0.1 3.8 0 0 75 4.2 58 75 Arizona 409 39 21 2,130 29 39 0 119 12 42 2,830 12 Arkansas 135 38 0.4 4,930 244 108 0 0 0 5.2 5,460 0 California 2,740 108 75 10,800 234 522 10 14 151 3.6 14,500 183 Colorado 100 27 7.7 2,020 23 37 0 25 17 22 2,260 17 Connecticut 65 55 25 16 1.4 3.5 0 0.3 0 0.2 165 0 Delaware 40 12 2.8 34 3.8 17 0 0 0 0.2 110 0 District of Columbia 0 0 0 0 0 0.5 0 0 0 0 0.5 0 Florida 1,860 297 50 1,670 50 240 0 148 0 21 4,340 4.6 Georgia 263 99 36 476 9.7 295 0 8.7 0 4.8 1,190 0 Hawaii 200 2.4 45 173 7.5 19 0.9 0.5 0 67 515 16 Idaho 180 65 9.8 2,520 17 39 0 1.2 0 0 2,830 0 Illinois 371 129 16 180 54 162 0 5.5 25 11 928 25 Indiana 319 115 45 61 28 119 0 10 0 11 709 0 Iowa 257 45 18 35 82 74 0 1.1 0 15 528 0 Kansas 181 24 4.9 3,150 91 35 15 13 0 14 3,500 15 Kentucky 55 23 8.0 0.5 2.3 92 0 7.4 0 38 226 0 Louisiana 294 39 10 475 144 356 0 0.4 0 31 1,350 0 Maine 25 35 9.5 2.6 1.4 4.6 0 1.3 0 0.7 80 0 Maryland 83 73 19 37 13 19 0 0.9 0 1.8 246 0 Massachusetts . . . 192 34 12 28 1.5 38 0 0.5 0 46 351 0 Michigan 348 194 16 101 13 177 3.6 7.1 0.8 3.6 858 4.4 Minnesota 331 88 46 120 62 57 0 6.3 0 1.9 712 0 © 1999 by CRC Press LLC © 1999 by CRC Press LLC Mississippi 302 33 16 1,540 377 166 0 3.5 0 42 2,590 0 Missouri 226 58 13 535 20 27 0 8.6 0 9.5 891 0 Montana 55 17 0 82 16 31 0 2.6 13 0 204 13 Nebraska 232 42 0.3 5,780 108 26 0 6.1 4.7 4.4 8,200 4.7 Nevada 117 11 7.1 641 1.0 47.4 0 65 11 6.3 855 42 New Hampshire . . 31 31 12 0.3 0.6 5.6 0 0 0 0.8 81 0 New Jersey 387 88 17 32 1.5 43 0 2.4 0 1.9 580 0 New Mexico 277 28 18 1,280 26 6.3 0 81 0 9.3 1,700 0 New York 552 144 136 16 22 127 0 11 1.5 0 1,010 1.5 North Carolina . . . 134 172 7.3 57 69 61 0 12 0 0.1 333 2.1 North Dakota 30 12 0.1 59 14 3.6 0 3.8 0 0.3 122 0 Ohio 497 138 28 12 7.6 158 0 47 0 19 905 0 Oklahoma 99 30 6.6 755 45 3.8 0 5.4 259 3.5 959 259 Oregon 124 61 4.4 880 3.1 13 0 1.2 0 0 1,090 0 Pennsylvania 243 145 16 5.2 48 85 0 211 0 6.2 762 0 Rhode Island 16 7.3 1.5 0.7 0.5 1.1 0 0.5 0 0 27 0 South Carolina . . . 107 71 1.7 27 12 80 0 2.9 0 39 322 0 South Dakota 53 9.3 6.1 65 18 4.1 0 7.8 0 3.4 167 0 Tennessee 277 54 2.0 9.9 21 66 0 2.8 0 0 435 0 Texas 1,130 130 33 6,530 139 228 0.5 128 409 59 8,370 411 Utah 293 7.7 3.8 393 7.8 55 0.1 16 7.3 0 776 14 Vermont 15 18 9.5 0.4 4.6 1.9 0 0.3 0 0.4 50 0 Virginia 82 125 28 5.8 7.8 107 0 2.6 0 0.4 358 0 Washington 631 125 24 819 24 133 0 2.8 0 0.5 1,780 0 West Virginia 38 40 38 0 15 13 0 3.7 0.5 0.5 146 0.5 Wisconsin 311 92 17 167 79 78 0 7.9 0 5.8 759 0 Wyoming 38 9.7 0.9 181 13 1.6 0 71 18 1.0 317 18 Puerto Rico 95 6.4 1.2 33 4.5 10 0 2.8 0 2.2 155 0 Virgin Islands . . . 0.3 0 0.1 0 0.1 0.1 0.2 0 0 0 0.5 0.2 Total 15,100 3,310 940 49,000 2,280 4,010 30 1,060 1,010 565 76,300 1,130 *Figures may not add to totals because of independent rounding. All values are in million gallons per day. © 1999 by CRC Press LLC © 1999 by CRC Press LLC are stringently regulated insofar as what toxic materials may be placed in them. Liquids are banned. Furthermore, double liners usually are required around the land- fills in order to trap liquids leaching from the wastes. These liquids then are pumped up into suitable containers and disposed of properly. Finally, only a very few landfills are allowed to handle toxic materials, perhaps as few as one or two per state. Even the number of conventional landfills has dropped sharply as many permits have expired and were not renewed. In order to obtain permits under RCRA, owners and operators of hazardous waste facilities usually must install groundwater monitoring wells to detect contam- ination from the facilities and undertake the necessary corrective measures. The EPA has adopted a twofold approach to RCRA permitting standards: • Liquids management. • Groundwater monitoring and response. The first, liquids management, minimizes the generation of leachate that might contaminate groundwater. The second compares groundwater contamination to that which occurs naturally in the uppermost aquifer or the maximum contaminant levels (MCLs) for contaminants listed under the Safe Drinking Water Act, whichever is less. If those values are exceeded, then corrective actions must be taken. Sole-source aquifers are those which are the sources of present or future water supply to an area where there is only one aquifer available for that purpose. Consequently, these aquifers are subject to rigid regulations that are intended to protect them from becoming contaminated. The Safe Drinking Water Act calls on states and local governments to identify critical aquifer protection areas that are eligible for special protection. EPA regulations provide criteria for states and local governments to use for the identification of such aquifers. This necessity is especially true in states like Florida and New Jersey which face precarious future water supply situations. In doing a NEPA study, therefore, any possible effect of the proposed project on sole-source or critical aquifers must be given close scrutiny. As a corollary to this, aquifer recharge areas and the effects of the proposed project on them also must be considered. For many years, the underground injection of wastes, for example, cyanide and heavy metals from the steel industry, was a commonly accepted practice. These wastes were injected into aquifers that thus became contaminated and therefore unsuitable for future use as public water supplies. In recent years, the EPA has placed increasingly stringent restrictions on this practice and has reduced the amounts of permitted underground injection activity drastically. The apparent goal is eventually to eliminate this practice entirely. For those applicants who desire to start or continue underground injection, the EPA has placed underground injection wells in five categories or classes according to the nature of the substance and the threat it poses. The EPA considers whether or not to allow operation of those wells through one of two mechanisms—by general rule or by individual permit. © 1999 by CRC Press LLC In the cases of those underground injection wells that the EPA allows to function by general rule, the owner/operator is required to submit to the EPA or the state that has been delegated authority an inventory of the underground injection wells and, for certain classes, the rates of injection. Reports also may be required on groundwater monitoring and analyses of fluids injected into the wells. Thus, for Class I wells the owner/operator is required to: • Install and maintain groundwater monitoring wells. • Monitor continuously injection pressure, flow rate volume, and other char- acteristics. • Analyze injected fluids. • Report quarterly data on injection pressure flow rate, volume of injected fluids, results of groundwater monitoring, and any tests of the well ordered by the agency during the period. When authorized by permit, the EPA or the state must require a form of moni- toring that will produce data representative of the activity being monitored. The per- mittee is required to present these results (40 CFR 146). The permit will also require the owner/operator to report any changes in the facility. Any incident of noncompli- ance with permit conditions that endangers an underground source of drinking water must be reported to the agency within 24 hours. These regulatory controls ensure the mechanical integrity of the injection well operations, as well as ensure that none of the well’s contents migrate into under- ground sources of drinking water. Information collected subsequent to authorization by rule or permit enables the EPA or the states to remain informed about the contents and operating characteristics of these wells and the status of groundwater in the area. In this way, changes in rules or permits can be made and, when necessary, enforce- ment actions can be taken. Leaking underground storage tanks (UST) are a major source of groundwater contamination. The 1984 RCRAAmendments gave the EPA responsibility to develop a program to minimize this problem and penalties to enforce it. The various states, in turn, have established requirements such as corrosion control and overflow preven- tion for existing tanks. These matters are discussed in more detail later in this book in Chapter 11. 8.2 GROUNDWATER CONSIDERATIONS IN NEPA STUDIES NEPA type projects should meet certain requirements to ensure that they do not result in groundwater contamination. These requirements will necessitate answers to the following typical questions: • Does the project include injection of contaminants into the ground? • Will products that could contaminate groundwater be stored underground or used in some other manner that could contaminate groundwater? © 1999 by CRC Press LLC • To what extent will totally impervious surfaces be constructed during the project? • Will run-off from impervious surfaces be drained into on-site holding systems? • Are construction activities likely to contaminate groundwater or to disturb clay layers that seal off existing contaminants from the aquifers below them? • Is the groundwater a present or future source of drinking water? What is its water quality? Data sources typically used to develop baseline groundwater condition descrip- tions include: • USGS groundwater papers. • State geological survey. • State water resource agencies. • State and local public health departments. • USGS hydrologic atlases. • EPA reports. • Permittee/grantee groundwater investigations. When more localized or detailed data are required, one may utilize available wells or subcontract the drilling of test wells. The quantity of groundwater associated with an aquifer can be determined by techniques such as soil conductance measurements and resistivity surveys. Pump tests and slug tests are performed to determine aquifer characteristics such as trans- missibility and storage coefficients. For shallow water tables, field methods include monitoring wells and piezometer installation for direct observation and measuring rates of groundwater level increase or dissipation of added water. The NEPA analy- sis also estimates the reduction of aquifer recharge areas as a result of development and the resultant effects on groundwater quantity. In determining the quality of groundwater, one utilizes records from well sam- pling published by USGS and federal, state, and local public health authorities. Supplementary investigations may be conducted by sampling wells, springs, and recharge areas through the installation of peizometers and water quality monitoring instruments in observation or collection wells. Physical water quality criteria are measured at the sampling point (temperature of sample) or evaluated in the labora- tory (turbidity, color, odor, and taste). Various methods may be used to determine groundwater impacts according to specific needs. The appropriate methodology depends in part on the significance of groundwater impacts as determined during scoping of the project, the geology of the study area, the present and future demands on the groundwater resource, and the pri- mary and/or secondary impacts of the proposed action or alternatives on the ground- water resource. In many NPDES projects, the volume of groundwater consumption has been a major issue, as has been saltwater intrusion along coastal areas. In these © 1999 by CRC Press LLC instances, it is necessary to calculate cumulative groundwater consumption to deter- mine impacts on the aquifers and the effects on other users. The quality of groundwater at or near sites proposed for development may be sensitive to additional chemical or hydrogeologic stresses imposed by the activity. Groundwater quality monitoring programs in conjunction with quantitative ground- water studies therefore may be required. Other uses of groundwater which fall between the two extremes of human con- sumption and deep-well injection are dependent on a variety of water quality criteria. Each NEPA study must address the effects of the proposed project and alternatives on regional groundwater supplies. Significant aquifer recharge areas are identified based on surface drainage pat- terns, soil types, subsurface strata, aquifer permeabilities, and groundwater flows. Much of the information collected on topography, soils, and other geologic charac- teristics of a study area is utilized in this analysis. Estimates of sustainable yield from an aquifer are derived from an analysis of the regional water budget. The precise locations of significant recharge areas and important aquifers are graphically delin- eated on maps of the study area for the EIS. To address the effects on groundwater quality of a proposed project, one must first analyze the effects of weathering on any exposed material on the site to deter- mine the nature of the leachate that is produced. The chemical characteristics of the leachate are identified and its effect on existing groundwater (both near-surface and deep aquifers) is assessed. It is also necessary to assess the effects on groundwater quality of dewatering operations and the potential for degradation of surface water quality by groundwater discharges (Conservation Foundation, 1987). Mitigating measures are primarily preventive in nature. The most effective mea- sures are those that prevent groundwater contamination by not permitting the opera- tion that would contaminate the groundwater to proceed. The use of proper liners for ponds or basins containing possible contaminants is one practical mitigating mea- sure, while double liners of plastic or the use of impermeable clay liners for landfill operations also may be effective. Cleanup of contaminated groundwater is a lengthy and expensive process which may or may not be effective, depending upon the par- ticular situation. REFERENCES Briggs, G. F., Developing groundwater resources, in Handbook of Water Resources and Pollution Control, Gehm, H. S. and Bregman, J. I., Eds., Van Nostrand Reinhold, 1976, 300. Groundwater protection, Conservation Foundation, Washington, D.C., 1987. Salley, W. B., Preliminary estimates of water use in the United States, 1995, U.S. Geological Survey Open-File Report 97-654, Reston, VA, 1997. © 1999 by CRC Press LLC . 293 7.7 3 .8 393 7 .8 55 0.1 16 7.3 0 776 14 Vermont 15 18 9.5 0.4 4.6 1.9 0 0.3 0 0.4 50 0 Virginia 82 125 28 5 .8 7 .8 107 0 2.6 0 0.4 3 58 0 Washington 631 125 24 81 9 24 133 0 2 .8 0 0.5 1, 780 0 West. 42 New Hampshire . . 31 31 12 0.3 0.6 5.6 0 0 0 0 .8 81 0 New Jersey 387 88 17 32 1.5 43 0 2.4 0 1.9 580 0 New Mexico 277 28 18 1, 280 26 6.3 0 81 0 9.3 1,700 0 New York 552 144 136 16 22 127 0. 3 .8 0 0.3 122 0 Ohio 497 1 38 28 12 7.6 1 58 0 47 0 19 905 0 Oklahoma 99 30 6.6 755 45 3 .8 0 5.4 259 3.5 959 259 Oregon 124 61 4.4 88 0 3.1 13 0 1.2 0 0 1,090 0 Pennsylvania 243 145 16 5.2 48 85