erate the closed cycle cooling systems and to compensate for loss of efficiency. The fuel penalty will be approximately the equivalent of 18 million tons of coal by 1977 and 33 million tons by 1983 (total increase in demand for nuclear and fossil fuel expressed in million Btu, divided by a heat value of 24 million Btu/ton). This penalty amounts to an increase in the national demand for energy of only 0.5 percent by 1977 and 0.7 percent by 1983. Thus, the thermal effluent guidelines should not significantly increase the imbalance between national energy demand and domestic supply.

Impact of Legal Exemptions. The above estimates are based on the cost of installing mechanical draft cooling towers on all plants included in the 1977 and 1983 standards (Table IV-23). However, the number of plants that will actually be required to install mechanical draft cooling towers will be considerably less due to the following factors:

• Exemptions under 316(a) where alternative cooling systems are capable of assuring the propagation of a balanced biotic community.

• Exemptions due to lack of land or adverse environmental impact from salt water drift.

• Ability of some power plants to comply with the guidelines by installing less expensive closed cycle cooling systems such as cooling ponds and spray canals.

In order to estimate the number of plants that would fall into each of these categories, it would be necessary to have at least the following information for each plant:

• Feasibility of assuring a balanced biotic community with alternative cooling system.

• Maximum acreage the utility owns that could be made available for closed cycle cooling system.

• Projected concentration of salt water drift.

While at the present time information has not been compiled for the last two factors, an analysis was made of the impact of exemptions under section 316 (a) of the 1972 Amendments. The analysis was based on the following assumptions:

32 percent of the existing capacity covered under the maximum impact case would have to install cooling towers on 60 percent of the plants' total capacity. The plants could meet water quality standards by operating the cooling towers only 30 percent of the time.

*Self-generated power is evaluated for each industry at the same cost per kilowatt-hour as it pays to buy electric power.

Only a part of SIC 2819 (industrial inorganic chemicals). Value of shipments by these plants cannot be isolated. Source: 1967 Census of Manufactures. Bureau of the Census. Volume II, Industry Statistics, Part 1, pp. 28-42; Volume II, Industry Statistics, Part 2, p. 28A-9; Fuels and Energy Consumed, Special Series MC (67) S-4, p. 18-SR4.

Electric Energy Purchased, Generated and Used, and Maximum Demands, at Major Atomic Energy Commission Installations by Months for 1967 (unpublished table). Federal Power Commission. July 1968.

• A new plant that is not planning some type of off-stream cooling will have to install cooling towers on 60 percent of its capacity. The plant could meet water quality standards by operating the cooling tower only 30 percent of the time.

All plants that are currently planning to install cooling towers will be required to operate the cooling tower 60 percent of the time on 100 percent of the plants' capacity. As shown in Table IV-27, these exemptions would reduce the required capital expenditure from $9.5 billion to $2.3 billion in 1977 and from $15.3 billion to $4.4 billion in 1983. The projected price increase would fall from 3.2 percent to 0.8 percent by 1977 and from 2.9 percent to 0.9 percent by 1983. The exemptions would reduce the cost to the consumer $1.5 billion per year by 1977 and $2.2 billion per year by 1983.

V. NONPOINT POLLUTION

Nonpoint sources of water pollution vary considerably in type and stem from a broad range of human activities and natural causes.* The activities may be divided into five broad categories of agricultural-rural, forestry, construction, mining, and urban. In many areas, pollutants stemming from these activitiesincluding sediments, organic wastes, salts, minerals, acids, and chemicals such as pesticides, herbicides, and fungicides— constitute a problem equal to or exceeding that of point source. pollution.

Singly and in combination, these pollutants present a broad range of problems. In many Western streams, dissolved solids present the most pernicious problem. The increasing salinity of the Colorado River, for instance, threatens use of this important water source for agricultural as well as municipal and industrial purposes; most of the salinity stems from nonpoint sources-47 percent from salt springs and other natural sources, and 38 percent from irrigation. In Appalachia and other coal-producing areas, acid mine drainage often constitutes the most intractable problem. An estimated 20,000 acres of lakes and more than 12,000 miles of streams suffer damage from mine discharge or drainage. Sediments and other nonpoint source pollutants similarly present a variety of problems.

As Federal and State pollution control policies have developed, most attention has been directed toward point sources of pollution. Nevertheless, certain States such as Iowa have shown leadership in the control of nonpoint sources. At the Federal level, the 1972 Amendments took initial steps to develop a nonpoint source control program.1 The Amendments require EPA to develop information on the nature and extent of nonpoint sources of pollution and the means to control such pollution from a range of activities. Similarly, the Amendments require States to submit reports on nonpoint sources of pollution, and regional planning and operating agencies to recommend and develop control programs.

EPA has published the required series of reports on the nature and extent of nonpoint sources of pollution. Four are based on the types of activities that produce such pollution: agricul

*Nonpoint sources of water pollution are not defined by the 1972 Amendments. EPA considers all sources to be nonpoint that are not subject to National Pollution Discharge Elimination System permits.

1

Sections 303 (e), 304 (e), 305(b), and 208, Federal Water Pollution Control Act Amendments of 1972 (P.L. 92-500).

tural, silvicultural, mining, and urban and rural construction.2 Three cover unique problem areas that may cut across these types of activities: disposal of pollutants in wells or subsurface excavations, salt water intrusion, and hydrographic modification. A final report covers analytic methods for identifying and evaluating the various sources of nonpoint pollution.*

In none of these reports, however, is there significant coverage of control costs and economic impacts. The omission may be attributed primarily to a paucity of reliable information. In an effort to correct, in part, the information deficiency, EPA contracted with Iowa State University to study the costs and impacts associated with two major agricultural pollutants-sediment runoff and nitrogen fertilizer. The remainder of this chapter discusses the results of that study.

The Problem

As the real prices of capital inputs such as fertilizers and equipment have declined, the American farmer has used them widely and intensively, substituting them for both land and labor. As a reflection of these declines, the ratio of the index of fertilizer price to the index of farm crop prices declined from 0.98 in 1940 to 0.64 in 1971. Similarly, the ratio of the farm machinery price to farm labor price declined from 1.19 in 1940 to 0.50 in 1971. With modern technology and substitution of capital for land, the Nation's relative land supply is greater than at any time in the last 100 years. Cropland has remained relatively constant over the past two decades, but total crop output has increased nearly 40 percent. The same crop output could have been produced under a less intensive production pattern, perhaps reducing the amount of runoff and contamination accordingly. Until

2 Methods and Practices for Controlling Water Pollution from Agricultural Nonpoint Sources, EPA-430/9-73-015; Processes, Procedures, and Methods. To Control Pollution Resulting from Silvicultural Activities, EPA-430/9–73– 010; Processes, Procedures, and Methods To Control Pollution From Mining Activities, EPA-430/9-73-011; Processes, Procedures, and Methods To Control Pollution Resulting From All Construction Activity, EPA-430/9-73-007. 'Ground Water Pollution From Subsurface Excavations, EPA-430/9-73012; Identification and Control of Pollution From Salt Water Intrusion, EPA-430/9-73-013; Control of Pollution Caused by Hydrographic Modifica

tions, EPA-430/9-73-017.

'Methods for Identifying and Evaluating the Nature and Extent of NonPoint Sources of Pollutants, EPA-430/9-73-014.

Environmental Impacts and Costs in Agriculture in Relation to Soil Loss Restrictions and Nitrogen Fertilizer Limitations. The Center for Agricultural and Rural Development, Iowa State University. Ames 1973.

1973, however, Federal programs encouraged the trend toward more intensive farming, with an attendant increase in use of chemicals and similar inputs, by guaranteeing prices (coupled with restricting acreage), subsidizing irrigation development, and providing tax advantages.

While chemicals and similar inputs increase productivity, they can also have adverse environmental impacts. One impact is direct-unused fertilizers and organic chemicals flow into streams and underground water supplies. Another major impact is indirect. Fertilizers and pesticides lessen the need for rotational systems, forages, and mechanical practices. Hence, row crops can be grown more intensively and even continuously on the same fields, and the land loses more water and sediment. The sediment not only contaminates streams, but-along with water runoff-it also provides the transport mechanism by which a greater proportion of residual fertilizers and pesticides are carried into streams.

Technological and economic development of agriculture has also had beneficial effects on the environment, because it has resulted in fewer acres farmed and better use of less erosive lands. Substituting machines for animals means that less land is needed for feeding working animals and that tractors are polluting an average of only 500 hours per year compared with animals that generate wastes year-round.

Study Design

The Iowa Study examines supply capacity, productivity, farm income, food prices, and other economic impacts that might prevail under a selected set of environmental policies for agriculture. The study focuses on the year 2000, a period long enough to allow additional domestic and export demands for food to impinge on agriculture and to allow sufficient time for agriculture to adjust to new environmental restraints.

The following basic assumptions were made:

A free market will exist for commodities included in the analysis.

Existing technology will be applied increasingly in crop and livestock production.

Per capita imports of agricultural commodities will be maintained at recent levels.

• The national population will be 280 million in the year 2000 (Bureau of the Census, level D estimate).