INTFP-DKPAKTMEN'T'AL TASK FORCE 0?? PRn.TErT si IB-TASK ^OPCE ON V/ATEP February 1, 196? ------- 841 R67O01 INTER-DEPARTMENTAL TASK FORCE ON PROJECT POTOMAC SUB-TASK FORCI-: ON WATER QUALITY FINAL REPORT February 1, 1967 ------- UNITED STATES ,- . ' DEPARTMENT OF THE INTERIOR FEDERAL WATER POLLUTION CONTROL ADMINISTRATION The Honorable Kenneth Holum Chairman, Inter-Departmental Task Force on Project Potomac Department of the Interior Washington, D. C. 20240 Dear Secretary Holum: The Water Quality Sub-Task Force of the Inter-Departmental Task Force on "Project Potomac" submits herewith its final report on its activities and findings regarding vater quality problems in the Potomac River Basin. • . During the past year, and following submission of its-Progress Report of November 1, 1965, the Sub-Task Force was able to arrange for the initiation of a number of, studies and investigations as ah aid in completing .its assignment. Some of these investigations are still underway, but,most of them have been carried to, the point where some tentative conclusions could at least be drawn. The Sub-Task Force was exceedingly'fortunate regarding some of . these studies in that the Federal Water Pollution Control Admin- istration already ha.d underway its comprehensive study of water pollution in the Chesapeake Bay drainage basin, as part of its Chesapeake-Susquehanna Comprehensive Project. The field staff assigned to this project, located at Annapolis, Maryland, under- took a number of special investigations at the request of the Sub-Task Force, and also made available findings resulting from its continuing studies in the Potomac Basin. Without the exist- ence and cooperation of the project, the Sub-Task Force could not have completed its assignment. " ' In additionfto the forgoing studies, the Federal Water Pollution Control Administration also provided assistance through staff of „ its Regional Office in Charlottesville, Virginia, its research and technical services staffs in Cincinnati, and its Headquarters Office. ' Other agencies who were consulted, or who undertook studies or provided data for the Sub-Task Force were the Sub-Task Forces on Water-supply and Flood Control and on Erosion and Sedimentation, the staff of the Interstate 'Commission on the Potomac River Basin, the District Office of the Corps of Engineers, the Department of ------- - 2 - « Sanitary Engineering of the Government of the District of Columbia, the Metropolitan Washington Council of Governments, the Tennessee Valley Authority, the Chesapeake Bay Institute and the Faculty and graduate students of the Johns Hopkins University, the U.S. Geological Survey, the U.S. Public Health Service, the Maryland Office of the Soil Conservation Service, the Agricultural Research Service, and the Dow Chemical Company, The Sub-Task Force gratefully acknowledges the splendid cooperation and assistance of these various organizations and of the individuals associated with them. It also wishes to record its thanks to the representatives of the four States and the District of Columbia who, as observers and members of the Governor's Advisory Committee on the Potomac River Basin, met with the Sub-Task Force, participated in its discussions and provided advice and council. The Sub-Task Force desires to point out, however, that these observers are not to be considered as sharing in any of the responsibility for this Report. For the Sub-Task Force on Water Quality. Sincerely yours, 0! Earl J. Anderson Chairman, Sub-Task Force on Water Quality Enclosure ------- 2 9 9 9 10 CONTENTS Page Letter of Transmittal Roster of Members and Associates, Sub-Task Force on Water Quality 1 Summary of Findings, Conclusions and Recommendations Section I - Introduction 1« Foreword 2. Assignment of the Water Quality Sub-Task Force 3. Scope and Limitations of the Report h. Sub-divisions of the Potomac River Basin n Section II - Water Quality Requirements; Criteria 12 1. General Objectives . 12 2. For Recreation and Esthetic Enjoyment . '12 3. For Swimming 12 1*. For Municipal Water Supply 13 5. For Fish and Aquatic Life 13 6. Other , Ih Section III - The Flowing River Portion of the Basin 15 1. Existing Pollution 15 2. Studies and Investigations Undertaken 15 3. Inventory of Waste Discharges, Stream Conditions and 15. Treatment Needs 1+. Flow Regulation Storage Requirements IT 5. Nutrients, Algae and Rooted Aquatic Vegetation IT 6. Herbicides for Control of Aquatic Vegetation 19 T( Mine Drainage and Mineral Pollution 20 ------- 8. 9. 10. 11. 12. 13. Section 1. 2. 3. U. 5. 6. Page Sedimentation 22 Bacterial Pollution - Limitations on Swimming 22 Problems of Swimming in Small Impoundments - 23 Need for Re-Study of Bacterial Swimming Standards 2U Physical Suitability of the Potomac for Swimming . 2k General Conclusions Regarding Water Quality in the Flowing River 2U IV - The Estuarine Portion of the Basin 26 Area Affected by Pollution • 26 The Upper Estuary - Existing Water Quality Conditions 26 Existing Waste Treatment Facilities ' 27 Additional Facilities and Programs Required 28 Investigations and Studies Undertaken 28 Problems of Nutriert Reduction for Algae Control - Alternative Proposals 28 (a) Dilution by Flow Regulation . 29 (b) Schemes for Diversion of Wastes Out of the Basin 30 (c) Diversion of Wastes to the Lower Estuary 31 '(d) Renovation and Direct Re-Use' of Waste Waters 31 (e) Advanced Waste Treatment for Phosphorus Removal 33 31* (f ) Dilution of Residual Phosphorus after Advanced Treatment 7. 8. 9. (g) Multiple Attack Methods of Reducing Phosphorus 3^ Additional Requirements for Reduction of BOD ' 37 Pollution from Combined and Storm Sewer Overflows 37 Sedimentation Problems 39 ------- Page 10. Turbidity Problems UU 11. Accumulated Sludge Deposits and Bottom Muds 1*5 12. Pollution from Boats and Marinas U6 13. Bacterial Pollution - Limitations on Swimming UT lU. Use oT Upper Estuary for Emergency Water Supply U8 15. General Conclusions Regarding the Upper Estuary kg ection V - Implementation . 51 ection VI - Needed Additional Studies . 52 1. Weed for Reexamination of Bacterial Standards for Natural Swimming Waters 52 2. Need for Reexamination of the Flow Regulation Provisions of the Federal Water Pollution Control Act* 51* ------- Edmund Couch, Jr. Walton Durum Lloyd. Reed (to Dec. 30, 1965) Carl Fetzer (after Dec. 30 s 19o5) Keith Krause (to June 30, 1966) • Earl J. Anderson (after June 30, 1966) INTER-DEPARTMENTAL TASK FORCE 0?. . PROJECT POTOMAC SUB-TASK FORCE ON WATER QUALITY . MENSSRS Corps of Engineers, U. S. Army . U. S. Geological Survey, Dept. of the Interio Soil Conservation Service4 Dept. of Agricultu Soil Conservation Service» Dept. of Agricultu: Ci'.iirrr.ars; Federal V/ater Pollution Control Administration, Depts. of nEw and Interior Chairman; Federal Water Pollution Control Administration^' Dept. of the interior OBSERVER ASSOCIATES - REPRESENTATIVES OF-THE GOVERNORS ADVISORY COr-KITTEE ON THE POTOMAC RIVER BASIN aiter Lyon Paul Kc?:oo Noel Val^nza Albert Paessler 'D, C. Depo. of Health ?a. Dept. of Health .Md. Board of V/ater Resources Md. Dept. of Health Ya. Board, of Water Control 2ern Wright (to Juno 8t 1966) Wes^ Virginia Dept. of Natural Resources .Edgar Henry (a.v'ter J\:r:c 5S 1966) West Virginia Dept. of Natural Resources ADVISORY ASSOCIATES FROM STAFF OF THE INTERSTATE COMMISSION ON THE. POTOMAC RIVER BASIN Keith Fry Carl Johnson c "^ r*O 7?rp A p v TP'" ^" T V o/!iL..n£jJ.Ai\I — jii-ju-iii Kelvin 2. Scheldt GR AND COORDINATOR OF STUDIES Federal Water Pollution Control Administration Depts. 01' HEW and Interior ------- SUMMARY OF FINDINGS AND CONCLUSIONS 1. The assignment of the Sub-Task Force on Water Quality was to (l) determine the quality of water needed for the various proposed uses of the Potomac River,* (2) ascertain the existing quality invbhe several reaches and tributaries of the river and (3) determine the remedial measures required and their costs in those situations where water quality is or will be unsatisfactory. Limitation of time and existing inadequacies in technical and scientific knowledge and basic data placed severe restrictions on the Sub-Task Force in accomplishing its assignment. The conclusions reached are tentative and some are conjectural and must await further investigation and research. Costs, where given, are based on very rough engineering estimates. For purposes of analysis, the basin was divided into (l) the upper, flowing river portion and (2) the estuarine or tidal portion. 2. Principle water quality requirements are that: dissolved oxygen should not be less than U iniligrams per litre 90% of the time nor less than 3 mg/1 at any time; dissolved phosphorus should not be greater than 0.1 mg/1; and coliform bacteria in swimming water areas should, on the basis of existing State Health Department requirements, be not more than 2,^00 per 100 mililitres for 90$ of the time nor more than 1,000 for 50$ of the time. Water intended for use as a public water supply source should meet the Public Health Service Drinking Water Standards. Recreational and environmental waters should be free of visible floating or suspended solids, oils and greases, heavy growths of rooted aquatic plants, slimes, and high concentrations of algae, and should not be discolored nor excessively turbid. Swimming water areas should be free of hidden hazards or other dangers. Water tempera- tures should not be elevated by industrial cooling processes to such a degree as to interfere with aquatic life. 3. In the "Flowing River" portion of the Basin: (a) Pollution from municipal and industrial waste discharges occurs at various places throughout the Basin, but certain areas, such as the kk mile reach below Luke, Maryland, and the 20 mile reach below Waynesboro, Virginia, are more acutely affected. Eighty-five percent of all municipal wastes, and eighty-three percent of all industrial wastes in the flowing river portion of the Basin now receive some treatment. However, new or additional biological or secondary waste treatment facilities are required at a number of locations throughout the basin to insure the removal of at least 85 percent of the BOD. present in the waste water effluents, and an equivalent level of treatment should be provided for all industrial waste discharges. In addition, some industrial discharges require further research before suitable treatment methods can be provided. * The 1965 amendments to the Federal Water Pollution Control Act require the respective States to establish by June 30, 19^7» appropriate criteria for various streams within their jurisdictions. When established, these standards may modify the findings of the Sub-Task Force. ------- (b) In addition to the waste treatment facilities called for in (a) above, flow regulation storage for water quality control, in amounts essentially equal to those called for in the 1963 report of the Corps of Engineers on the Potomac River, will be required at various places in the Upper Basin to meet the water quality goals described. These findings are based on the requirement that at all locations adequate treatment of the polluting wastes be first provided at the source. Adequate treatment was considered to be attainment on a basin or area wide basis of 80 and 85 percent reduction of the five day BOD in the discharges to the river, by the years 1985 and 2010 respectively, except in the Washington metropolitan area, where removals of 85 and 90 percent respectively are required. It should be noted that these are average levels, applicable to all wastes generated in the Basin and obtainable at all times, and include allowances for such untreatable pol- lution as storm water runoff. Actual treatment of wastes at the specific treatment plants would need to be at a higher level to achieve these averages. Because of the^multiple purpose nature of the flow regulation storage re- leases, with corresponding sharing in joint costs, preliminary estimates indicate that such storage would be cheaper than advanced waste treatment. Anticipated improvements in waste treatment techniques, when realized should, however, make practicable higher degrees of treatment, with corresponding reductions in the amounts of .flow regulation storage required to achieve the desired water quality goals. Therefore, at each stage of development of the Basin, the flow regulation requirements should be reexamined to determine the possibility of substituting advanced waste treatment as an" alternative to storage. (c) .The annual average concentration of phosphorus in the lower reaches of the flowing river and its tributaries is two and a half times the accept- able maximum. Most of this phosphorus originates on the land, and is chemic- ally bonded to soil particles. Treatment of municipal wastes to remove phosphorus would therefore accomplish little. Use of reservoirs as nutrient traps would also be relatively ineffective. Also, no practical processes have yet been devised for removal of nitrogen. There is therefore little prospect.of improving the nutrient situation in the upper river until better methods of removal or control are devised. Rooted aquatic plants will consequently continue to be present in considerable quantities in the non-mountainous portions, of the Basin. Herbicides have been proposed to control these plant growths, but much research will be required to develop specific selective herbicides which are not toxic to other plant or animal life. . ' (d) A total of 95 miles of streams in the North Branch sub-basin of the Potomac are affected by acid mine drainage. They are unsuitable for fish and are in many places esthetically unattractive because of deposits in the stream .bed of insoluble iron compounds. Satisfactory methods for controlling acid mine drainage have yet to be demonstrated, but research and demonstration studies have been initiated by the Federal Water Pollution Control Administration. Needed surface reclamation work on some 11,000 acres of pre-regulation disturbed mining lands is estimated to cost $10 million. Areas disturbed after passage of existing legislation are being controlled by the reclamation requirements. ------- (e) The Potomac River discharges some 2 1/2 million tons of sediments annually into the tidal estuary at Washington. Water- shed management practices proposed by the Department of Agriculture could, when completed, result in approximately a 50$ reduction in this sediment load. Reservoi :-n, if and when built, could further reduce this load. These sediments have relatively little physical effect upon the flowing river, but are damaging to the estuary. In addition they interfere with the esthetic enjoyment of the river and its environs during and following storms. (f) Bacterial conditions, as determined by widely scattered sampling during the prolonged dry Summer of 1966, were generally satisfactory for swimming in the main stem and some of the tribu- taries of the Potomac but unsatisfactory in the Shenandoah sub- basin. Other samplings, taken at other times, indicate that land run-off during storms generally raises the bacterial count in the river above the established swimming water standards. Such samplings, widely scattered in both time and space, should not be relied on, however, for determining the acceptability of the water for swimming at any specific location. The conditions which may prevail at any site require a detailed bacteriological examination extending over sufficient time to permit an evaluation under all conditions of flow and weather. A sanitary survey of the area is also required. Similar examinations are required for small impoundments intended for swimming use. Physical conditions should also be examined to ensure that physical hazards or un- attractive conditions do not exist. (g) The reliability of the bacterial standards used in judging natural swimming water quality is in question. These standards should be re-examined. This need is discussed in the section on Needed Additional Studies. .(h) It is generally concluded that, except for those areas affected by acid mine drainage, it should be possible to maintain or return the remainder of the basin to an esthetically attractive condition, suitable for general recreation and support of fish and wildlife. Provision of a suitable swimming environment within existing bacterial standards is questionable for much of the basin, however, but must in any case be determined on a local, site by site basis. Determination of costs of needed additional pollution control facilities must await completion of more detailed surveys. In the Estuary: (a) Only the upper, fresh water portion of the estuary, in and adjacent to the Washington Metropolitan region, is seriously affected by major pollution problems. The remainder of the estuary is generally acceptable for all appropriate uses except ------- for minor pollution conditions in a few.local areas adjacent to towns and villages', which should be readily correctable. (b) The Upper Estuary, from Little Falls to Quantico, is seriously polluted by discharges of inadequately treated waste waters con- taining excess quantities of organic oxygen demanding substances (BOD), heavy concentrations of phosphorus and other plant nutrients, and high bacterial loads resulting from inadequate chlorination. Large volumes of storm water and combined sewer overflows during storms also adds substantially to this pollution. Erosion from construction sites in the metropolitan area contribute 25 percent of the sediments deposited in the estuary, even though the area is only 2 percent of the total watershed area above this point. Heavy algal growths, stimulated by. the excessive amounts of phos- phorus and other nutrients create unsightly and noisome nuisances and, upon their decay, create a secondary pollution which helps depress dissolved oxygen in the estuary and promotes fish kills. (c) The District of Columbia waste water treatment plant at Blue Plains is not achieving the degree of waste treatment needed to meet the BOD reduction requirements of the 1957 Federal Water Pollution Control Enforcement Conference, and also requires con- struction of additional features to meet increased loads. Some other plants in the metropolitan region, including some at Federal establishments, also require improvements or expansion to meet these requirements. (d) The most serious pollution problem in the-upper extuary is that caused by the presence of nutrients, as evidenced by excess phosphorus, which stimulate the growth of algae- Dilution of these nutrients by 'flow regulation is for the most part impracticable. The major portion of these nutrients must therefore be prevented from reaching the estuary. (e) Diversion of the nutrient laden waste waters to other areas outside the basin, such as the Atlantic Ocean^ the Chesapeake Bay, or to spreading or underground injection areas, is considered too expensive or undesirable for other reasons. Diversion of the wastes to the lower estuary is equally* undesirable, for ecological and-other reasons. (f) Removal of phosphorus from the treated waste waters by advanced treatment appears to be an economical and practicable alternative at an additional cost of 5 to 6 cents per thousand gallons, but will not be sufficient by itself to control the algae blooms. (g) A combination of advanced waste water treatment, dilution by flow regulation releases from upstream storage, and dispersal of the highly treated wastes in the lower portion of the upper estuary ------- would probably maintain the phosphorus content in the upper estuary at or below the prescribed 0.1 mg/1. The least cost combination, for 1985 conditions, would require, in addition to advanced treat- ment, between 600 and 1,000 cfs of inflow from upstream at all times, plus diversion to and wide dispersal in the lower portion of the upper estuary of up to 250 mgd of the treated waste waters. (h) There is need for additional treatment for reduction of the BOD remaining in the waste waters following secondary treatment, in order to maintain a satisfactory oxygen level in the estuary. Advanced waste treatment for removal of phosphorus would probably also remove . sufficient residual BOD from the effluents to accomplish this objective. Flow regulation releases from upstream would there- fore apparently not be needed for BOD control, although they would contribute towards this end. (j) Application of the forgoing measures would probably make it possible to use the upper estuary as a possible emergency water supply source under certain conditions. Direct reuse of waste • waters for water supply purposes, after a high degree of treatment, has been examined as an alternative and is considered less feas- able than other available alternatives at this time. (k) Treatment and control of storm water and combined sewer overflow discharges are required for complete clean-up of the estuary for swimming and general recreation. A variety of detention and treatment facilities at about 1^0 locations through- out the Metropolitan Area might be needed for this purpose, at an estimated cost of about $2 billion, but considerable research, engineering investigation and demonstration will be required to determine the most effective methods to be used. (l) Even with the most effective application of watershed treat- ment measures, considerable sediment will continue to be deposited in the estuary. Dredging will continue to be required to maintain both the navigation channels and the general utility of the estuary as a recreational boating area. Extensive areas now exhibit serious shoaling with depths of from 1 to U feet, and this shoaling will continue. Salvage of these areas will require the dredging of several tens of millions of cubic yards of material. Location of suitable sites for disposal of the dredged material presents a difficult problem. (m) A program of sediment detention and erosion prevention measures to be applied at all construction and sub-division sites in the Metropolitan area is required to control local discharges of sediments to the estuary. The Sedimentation and Erosion Sub-Task Force is giving consideration to appropriate coordination with State and local governments to control this source of sediments. ------- 5. (n) Even with the best possible erosion control, the estuary will continue to present a muddy and hi/jhly turbid appearance after storms .which will persist for days afterwards because of tidal stirring. Application of polyelectrolytes to settle this turbidity, while not yet established as a fully effective measure, has been proposed to correct this situation. Costs are estimated at from one to one and one half million dollars per h month recreational season. (o) Accumulated muds and sludges on the river bottom do not present as serious a pollution problem as originally believed. With adequate waste treatment, these problems may disappear. Dredging to deepen the estuary would also alleviate this situation. (p) Boats are a source of pollution, especially at marinas, where hundreds of boats are berthed. Some of these marinas are on Federal property and measures to correct this situation should be taken under the directive regarding pollution from Federal establishments. State and local programs for the correction of boat and marina pollution in general are required. (q) Provision of treatment and disinfection for all waste water, storm water and combined sewer discharges to the estuary would greatly reduce the bacterial pollution in the estuary, but would not completely eliminate it. Very detailed examination of every stream and run tributary to the estuary, and the invoking of very exacting regulations regarding control and disinfection of all discharges to the streams would be required, as well as complete .elimination of all untreated wastes from boats and marinas, before the health authorities would be prepared to publicly sanction swim- ming in this portion of the estuary, and then only on the basis of regular bacterial samplings which indicated & favorable bacterial count, (r) It is generally concluded that it should be possible, at reason- able cost, to eliminate the algal bloom problem in the upper estuary, make it suitable for fish support and for a possible emergency source of water supply, and except during times of storms, esthetic- ally acceptable for environmental and general recreational uses. It might also be- possible at not too great a cost to reduce its un- sightly turbid appearance following storms by the application of coagulants. Beyond these measures, however, elimination of pollution from storm wate.r and combined sewer overflows, from boats and marinas, and from hidden sources discharging into the tributary creeks might require massive expenditure and many years to accomplish. Implementation of an effective pollution control program in the Potomac River.Basin requires: (a) Creation of an effective organization having the authority and responsibility, cooperatively with all affected levels of government, to develop and manage a pollution abatement program ------- involving provision of the extensive facilities and measures outlined above, and possessing the ability to respond effectively over time to inevitable changes in economic, social and political conditions. An implementing organization is probably the most important need revealed by this study. (b) A program of training, certification and supervision of waste treatment plant operators throughout the Basin. 6. Several problems of national significance requiring considerable additional study emerge from this review of water quality problems in the Potomac Basin. These are: (a) There is a widespread dissatisfaction with the existing bacterial standards used in evaluating natural swimming waters. It has become apparent that bacterial conditions in these waters cannot be accur- ately determined solely by the coliforirr criterion now used as a - statistical indicator of the presence of pathogens. Use of this index may be misleading, particularly where the coliform organisms originate primarily on the land rather than in municipal and indus- trial waste effluents, and reliance on it could preclude certain water uses despite the absence of pathogens. Better indices or other methods of determining bacterial pollution are therefore needed. Re-examination of the bacterial standards for natural swimming waters is therefore required and might well be'initiated in the Potomac Basin as a model for- the Country. The Secretary/- should, accordingly, press for initiation of such a study, to be undertaken cooperatively with the Public Health Service, the Agri- cultural Research Service of the Department of Agriculture, and appropriate other health oriented agencies and institutions of the Country. (b) Under- certain circumstances, the inclusion in Federal reservoirs of storage for water quality control at Federal expense, as provided for in the Federal Water Pollution Control Act, may be more costly or less desirable than some other alternative-such as diversion of the wastes to another water body, or advanced treatment. The Act now provides only for flow regulation storage, however, whereas the most economical or most desirable alternative should be the one actually adopted. Also, where flow regulation is appropriate in one •- part of the basin but another alternative is more economical or more suitable in another part of the same basin, this limitation can re- sult in inequitable demands upon some of the polluters, or incomplete provision of pollution abatement measures. This provision of the law should accordingly be broadend to permit consideration on an equal financ- ing basis of all alternatives, in situations where additional measures are required for pollution abatement following provision of "adequate" treatment of wastes at the source. Reexamination of this provision of the law, with the objective of developing suitable amending legislation, is recommended. Steps toward this reexamination are now being taken by the Department of the Interior, the Water Resources Council and the Bureau of the Budget. ------- REPORT OF INTER DEPARTMENTAL TASK FORCE ON POTOMAC RIVER SUB-TASK FORCE ON WATER QUALITY December 15, 1966 SECTION I" - INTRODUCTION 1. Foreword The goal established, by the President's directive to Secretary Udall, was to "Clean up the Potomac River and keep it clean so it can be used for boating, swimming, and fishing." In addition to these uses, however, the river and its tributaries must also serve as a source of municipal, industrial, and cooling water; supply certain amounts of agricultural water; provide an esthetically acceptable environ- • mental setting not only for the Nation's Capital^ but for .the intensive use of adjacent lani areas of the basin for recreation, residential and other development; serve, in its lower reaches, as a commercial shell and finfish area and as a navigation channel; and finally, serve as the vehicle for the final transportation and dis- posal of a large portion, if not all, of the basin's waste waters, after appropriate treatment. The task of determining how these objectives could be attained was assigned by the Secretary to an Inter-departmental Task Force, chaired by Assistant Secretary Holun. The Chairman, in turn, appointed four sub-task forces, to be concerned, respectively, with Water Supply and Flood Control, Erosion and Sedimentation, Recrea- tion and Landscape, and Water Quality. This document is the report of the Sub-Task Force on Water Quality. 2. Assignment of the Water Quality Sub-Task Force The Sub-Task Force on Water Quality was assigned the responsibility for: 1. determining the quality of water required for the several uses enumerated above; 2. ascertaining the existing quality of'the water in the several reaches and areas of the river in relation to the intended uses; and 3. in those situations where the existing or projected quality is not acceptable, determine the remedial measures required to bring it up to the level considered desirable for the uses contemplated, and the costs of so doing. ------- 10 3. Scope and Limitations of the Report The Sub-Task Force, in undertaking its assignment, has attempted, to deal with all phases of the water quality problem. The conclusions reached are, in most instances, however, tentative. The Sub-Task Force had the benefit of field work conducted by staff of the Chesapeake Field Station of the Federal Water Pollution Control Administration, but their studies are only now in progress, with much yet to be done before a definitive program for the entire basin can be developed. Tentative results of research investigations in waste treatment processes, now in progress, were also made available by staff of the Federal Water Pollution Control Administration, but these are subject to further modification as their findings are refined. The absence of historical as well as current detailed Water Quality records and data for many places in the basin has hampered evaluation of past and present situations. The question- able basis of some of the existing standards upon which the findings of the Group had to be based raises serious questions of policy which must be resolved before final recommendations for an action program can be made with confidence. Costs, where presented, are based on crude computations and the most meager of data, and are intended only to give some rough idea of the possible order of magnitude of the potential expenditures which might be expected. The combination of these factors means that there is a large potential margin for error in the evaluation of technology and in the assess- ment of costs upon which the tentative conclusions are based. Never-. theless, the Sub-Task Force believes that the report can be regarded as a reasonable first approximation of the possibility, practicability and feasibility of attaining within the basin the water quality goals set forth in the directive to the Task Force. With the exception of the North Branch, where detailed surveys • have been completed, consideration has been given to very broad reaches of stream only, in preparing the report. Shorter reaches within the areas discussed may have a water quality varying from that indicated. Closer examination would be necessary to judge water quality in specific areas actually proposed for recreation development. Such examination may require actual stream studies in the field to obtain current data. In considering swimming use, no detailed field evaluation was given to necessary access to the stream,- safety with regard to stream velocity, water depth, under, water obstructions, conditions of banks and bottom, and similar factors. In judging water quality for this use, major emphasis was placed on coliform concentrations and turbidity. In judging the suitability of waters for fishing, only the dissolved oxygen assets of the stream were considered. Other environmental factors such as type of stream bottom, water depth, aquatic life and temperature have an important bearing on fish survival and propagation. It is assumed that the evaluations being made by the Fish and Wildlife Service will judge these stream characteristics. ------- 11 In considering esthetic requirments, major attention was given to problems of elimination of gross pollution, nuisance factors, algae blooms, sediments, and other factors affecting physical appearance. In approaching its task as a whole, the Sub-Task Force kept in mind the objective of using the Potomac River as a model for the entire United States. Accordingly, certain broad policy issues are dealt with which, while directly affecting decisions in the Potomac, nevertheless are of equal importance Nationally in planning for the development of other river basins. Sub-divisions of the Potomac River Basin The Potomac River is essentially a combination of two distinctly different hydraulic systems; the "Flowing River," extending from the mountainous headwaters to the head of tide at Little Falls, and the "Tidal Estuary," extending from just below Little Falls to the Chesapeake Bay. With respect to the management of the waters of the basin, these two systems have a mutual inter-relationship which mast be recognized in planning for the use of the basin's waters, but from a physical, chemical and biological point of view, these ' two systems behave differently. They must therefore be studied and dealt with by different techniques. This report accordingly discusses the water quality problems of these two systems in seperate sections. ------- 12 SECTION II - WATER QUALITY REQUIREMENTS 1. General The water quality required for the several uses enumerated in the Introduction was made the subject of intensive study and discussion by the Water Quality Sub-Task Force. Based on its finding, the Sub-Task Force, in its November l , 1965 Progress Report, proposed a set of Water Quality Criteria as planning goals. These have, in general, again been applied in this report. For reasons discussed in the section on Policy Issues, however, it was found necessary to stiffen the bacterial parameter for swimming water quality to meet objections raised by the State Health agencies. Policy questions regarding the adequacy of the basis upon which these latter standards have been established are also discussed in Section VI on Policy Issues. The criteria, and/or modifications thereof are presented below. 2. For Recreation and General Esthetic Enjoyment. The water body must be free from visible floating, suspended and settle- able solids (especially from sewage, industrial or other waste origins) and debris. There should be no sludge deposits, and mud banks should not be in visible evidence nor cause shoaling which would interfere with the passage of boats. The water body should be essentially free from heavy growths of rooted aquatic plants, slimes, and high concentrations of algae and other plankton which cause excessive clouding. For control of such algae and plant growth, the inorganic dissolved phosphorus content of the water during the growing season should not be greater than 0.1 mg/1 as P(0.3 for PO, ). The water must.not be discolored or display excessive turbidity from sediments or other causes. There should be no visible oils, greases or emulsions, foaming, or emission of gases produced by decomposing organic matter. Water temperatures should not be elevated by industrial- cooling pro- • cesses to such a degree as to interfere with aquatic life or with the use of the area for recreation. 3. Additional Criteria for Natural Swimming Water Areas .and for Body Contact Snorts. (Note: A distinction must be clearly made between swimming in natural . waters and in artificial pools or organized bathing areas of intensive use. In the latter cases, a ~,uch higher bacterial standard is usually imposed because of the higher density of use, the absence of free water circulation, and the fact that coliform bacteria in any amount in such pools indicates fresh fecal pollution.) (a) The most probable numbers of coliform bacteria should be less than 2*400 per 100 milliliters (2^00/100 ml) for 90 percent of the time and less than 1000/100 ml at least 50 percent of the time, based on arithmetic averages. (The original proposal of the Sub-Task Force ------- 13 called for 1000 and 5000, based on geometric averages, a substanti- ally more liberal standard. See Section VI for further discussion) (b) There should be no discharges in the area of use of any sewage,. treated or untreated, no animal pollution, nor any substances which might be detrimental to the health of swimmers, even though the water otherwise meets all other criteria imposed. (c) The turbidity of the water should not prevent a Secchi disk from being visible through 5 feet of the water* i (d) The pH of the water should be within 6.0 and 9.0. (e) The area should be free from hidden rock outcrops, snags, tree stumps, heavy weed growth, pot holes and sudden drop-offs and muddy bottoms and banks. U. For Municipal Water Supply. The water in a stretch of river which is or may be utilized as a source of drinking water supply shall contain no substances that cannot be removed by conventional treatment normally capable of pro- ducing a finished drinking water complying in all respects with the Public Health Service Drinking Water Standards. The temperature of such water should not exceed 85°F. The dissolved oxygen should not be lower than 3 mg/1. Free ammonia should not exceed 0.3 iag/1 and the pH of the water should be within the range of 6.5 to 8.5. 5. For Fish and Other Aquatic Life. Dissolved oxygen should be not less than 1+ mg/1, 90% of the time, nor below 3 mg/1, at any time**, pH should be within 6.3 and 9.0, and specific conductance at 25°G (for fresh waters only) within the range of 150 to 500 times 10~° mho. Temperatures should not be above 93°F at any time***, nor greater than T3°F during the period of December through April. There should be no toxic substances detrimental to fish life. In shellfish growing areas, coliform bacteria must meet the State and Public Health Service requirements, the latter of which "states that coliform levels in shellfish growing water shall not exceed a median of 70/100 ml. for fully approved, unrestricted grow- ing areas and not over 700/100 ml. median in any case. This goal is considered desirable, but it is recognized that, under natural conditions, waters which do not generally meet it are and can be used for swimming by the general public. This fact, however, does not excuse water abuses which impair water quality and which are amenable to control. . **# por special cases such as trout streams requiring colder waters, these goals must be modified to suit the specific situation. ------- For Other Uses. Water of a quality satisfactory for the uses discussed above vill generally be satisfactory for other uses, such as agriculture and industry. ------- 15 SECTION III -. THE FLOWING RIVER 1. Existing Pollution - General Conditions. .Water quality in the flowing river section of the Potomac River Basin varies widely with location. Pollution at various points is cause'd by waste water discharges from municipalities and industries, acid mine drainage, and surface runoff from farms and other areas. Polluting substances include organic waste and chemicals, acids-, phosphate and nitrate plant nutrients, bacteria and sediments. 2. Studies and Investigations Undertaken. As part of its Chesapeake Bay - Susquehanna River Basin Comprehensive Studys the Federal Water Pollution Control Administration, in coopera- tion with various State and Federal agencies, municipalities and industries, undertook extensive field surveys to determine the sources and .extent of these polluting substances, the effects upon the river, .and the remedies required to reduce this pollution to acceptable levels and to maintain it at these levels. These studies and analyses are not yet complete,, but have progressed sufficiently to permit a reasonably accurate evaluation of the overall problem and of the remedial measures which appear to be required. As pointed out below, more refined investigation and analysis will be required to provide final solutions with respect to some problems and some specific locations. The results of the investigation to date are presented in the following paragraphs. 3. Inventory of Waste Discharges,, Stream Conditions and Treatment Meeds. An inventory of waste discharges from municipalities and industries was prepared by field staff of the Federal Water Pollution Control Administration, showing the location and characteristics of all dis- charges in the basin. While Appendix V of the Summary of Water Quality, Potomac River Basin in Maryland, October 1965, was used as a basis for this inventory, supplementary information received from the cooperating agencies in the various States occasioned some significant revisions. In the North Branch, the data were developed by the Federal Water Pollution Control Administration as part of its detailed sanitary survey of that stream. It should be noted, however, that the Maryland Department of Water Resources and the Virginia Water Control Board propose to compile waste inventories in December 1966, which will update the inventory and provide more •meaningful data. It should also be noted that: (a) Most of the basic data^were obtained from measurements and analyses by agencies other than the Federal Water Pollution Control Administration. (b) Most analyses were based on grab samples and may not be considered representative except in the few cases where taken regularly over, a long period of time. ------- 16 (c) Some plant performances vere based upon observer's physical inspection estimate. (d) Many plant data figures varied widely so that judgment had to be exercised in selecting the most representative figures. (e) For most of the small plants the figures were as much as five years old. The state agencies do not have the force to update the information except where the effluent has become a basis for complaints. Within the limitations surrounding the inventory as set forth above, the general observation can be made that about 85 percent of all municipal and 83 percent of all industrial was'tes receive treatment to seme degree. However, in addition to the need to provide treat- ment for the remaining 15 percent of the municipal discharges, a number of existing municipal plants will require either expansion of existing facilities to provide for increased loads, or increased degree of treatments or improvement in the operation of the treat- ment facilities provided. This is also true of a number of industrial discharges. In addition, some industrial discharges are of such a nature that further research will be required to develop suitable methods of treatment. Tannery wastes, such as those at Petersburg, West Virginia, and elswhere, are a case in point. These wastes are difficult to treat, and development of adequate methods and facilities will require a specific research effort. It is encouraging to note, however, that in the case of the Petersburgh situation, some research is already under way. The inventoryj plus visual inspection surveys and samplings of river water quality reveal certain areas where pollution problems are more extensive or acute than is generally the case in the basin as a whole. Thus, the North Branchs from Luke. Maryland for a distance of about Uk miles downstream is affected by the discharge of large quantities of untreated or partially treated industrial wastes as well as raw or partially treated sewage from several communities. This condition causes a lowering in the dissolved oxygen of the river, an increase in stream color} solids and turbidity, and the deposition of solids and sludge deposits, all of which detract from the utility and value of the stream for fishing, recreation and esthetics. Additional waste treatment facilities are badly needed in this section of the river. Similarly, the South River branch of the Shenandoah, for twenty miles below Waynesboro, is badly degraded by both municipal and industrial wastes. Elsewhere in the basin, the effects of inadequate waste treat- ment are less extensive but nevertheless detrimental. Substantial additional investigation, sampling and analysis will be required, however, before a complete, definitive statement of conditions and treatment requirements at all locations can be made. The Sub-Task Force nevertheless wishes to emphasize that it will in any case be • . ------- necessary to provide a minimum of secondary treatment of all wastes : wherever found, if the water quality goals set forth herein are to be achieved. This is the first, and most important requirement in dealing with pollution in the Upper Basin. Beyond such treatment, it will also be necessary to provide releases from storage during low flow periods, at certain locations, to maintain the desired water quality. This requirement is discussed more fully below. Weed for Flow Regulation Storage for Water Quality Control. Investigations previously conducted by the Division of Water Supply and Pollution Control of the Public Health Service (now the Federal Water Pollution Control Administration), in connection with the 1963 studies of the Potomac Basin by the Corps of Engineers, indicated the need for the provision of storage in a number of the proposed reservoirs in the Basin for the purpose of regulating river flows to maintain suitable water quality in the streams. These findings were based on the requirement in each case that adequate treatment of the polluting wastes at the source would first be provided. Adequate treatment was taken to be 80 and 85 percent removal of 5 day BOD in the basin in the years 1985 and 2010 respectively, except in the metropolitan area of Washington where removal levels of 85. and 90 percent respectively are required. It should be noted that these are average levels, obtainable at all times, and are applied to all wastes generated in the Basin. (See Vol. 5 of 1962 Corps of Engineers Eeport, p 8, for full explanation). The current studies on which this report is based confirm these earlier findings. On the basis of existing waste treatment techniques, only minor differences in the required storage volumes have been found. It must be emphasized, however, that extensive research into new methods of treating wastes, now under way, may produce new processes which could materially modify these requirements. Reexamination of the flow regula- tion storage requirements of th« Basin should therefore be undertaken at each new stage in the development of the basin, in connection with the planning of each successive dam and reservoir, at the time it is proposed for construction, to.reflect'and take advantage of new developments in waste treatment as these bee one available. In the determination of the need for flow regulation storage, evaluation should also be made of all possible alternatives for providing the needed improvement in river water quality following provision of "adequate" waste- treatment, and that alternative selected which is the most economical or for other reasons is considered the most desirable. Questions of authority, financing^ and equity are posed by this necessity. Problems surrounding consideration of these alternatives, including advanced waste treatmentr are discussed in more detail in Section VI on Needed Additional Studies. 5. Nutrients, Algae and Rooted Aquatic Vegetation. Except in the more mountainous sections of the Basin, upstream from the farming areas and urban communities, the waters of the Potomac ------- 18 "basin have been found to be rich in phosphorus and. nitrogen. Phos- phorus is of particular concern in studying the pollution problems of the basin because it is believed to be one of the key controllable elements in the promotion of excessive algae growths, expecially in the estuary. Phosphorus, jointly with nitrogen, is also thought to be primarily responsible for the substantial growths of rooted aquatic plants found in the streams throughout the basin below the forested, mountainous regions. Even if phosphorus should prove not to be the primary nutrient which stimulates plant growth, however, it serves as a good indicator of the concentration of other possible growth factors being contributed by sewage effluents. In the waters flowing out of the forested regions, phosphorus con- centrations are only about one half the amount considered allowable. In the remainder of the basin, the concentrations are substantially above this limit. Throughout the length of the main stem of the river inorganic phosphorus averages about 2 1/2 times the allowable limit of 0.1 milligrams per litre. Much of this phosphorus is believed to originate on farm land, how- ever, and reaches the river as a result of land runoff. A large part of this phosphorus is chemically bonded to soil particles and because it is only extremely slowly soluble, is unavailable for algae growth. At times of high flow, some of the increase in total phosphorus is also believed to result from re-suspension of sediments deposited in the river, to which the.phosphorus is attached. Upon reaching impoundments, or upon arriving at the head of the tidal estuary, that part of the phosphorus which is chemically bonded to the soil particles settles out, leaving only a relatively small part of the total phosphorus in solution and therefore available as an algal nutrient. Control of soil attached phosphorus is directly associated with control of runoff and erosion of sediments from the land, and no separate solution to this problem is presently discernible. Control of that part of the phosphorus which is in solution is largely associated. with provision of appropriate treatment of sewage and other waste odischarges. -While it would be entirely feasible to remove this phos- phorus by advanced treatment of these wastes, the recent studies of this problem by the Federal Water Pollution Control Administration staff indicate that it would result only in a small and ineffective reduction in the phosphates in the estuary. However, the phosphorus bonded to soil particles in the sediments of the stream bed may have some influence on the growth of the rooted plants in the flowing river portion of the basin. Studies of the effects of impoundments upon the phosphorus content of the stream indicate that this also would have little beneficial effect. Examination of the possibility of relying on an impoundment at the proposed Seneca Dam site to trap nutrients indicates that the Phosphorus trapping effeciency of the reservoir would be low and of ------- little benefit to the estuary, but the reservoir itself might suffer from serious infestation of rooted plants similar to those which in recent years have plagued some of the Tennessee Valley Authority reservoirs. The tentative conclusion reached is that in general it would be expensive and relatively ineffective to try to control or remove phosphorus in the flowing river portion of the basin by means of advanced treatment of waste discharges. In specific areas,.however, where rooted aquatic plants are especially troublesome, it may be desirable to undertake a thorough study to determine the reasons for such growths and the sources of any nutrients involved, as a basis for devising appropriate control measures. It can be expected, however, that rooted aquatic plants will in general continue to be present in considerable amounts in the streams of the Basin below the mountainous areas, especially during the warmer periods when stream flows are naturally low. While nitrogen is also an important plant nutrient, its removal or control presents difficult problems, and no practical process for accomplishing such removal is yet available. Much additional study must be devoted to the whole problem of nutrients before their effects . can be fully understood, and effective measures devised for their control. 6. Herbicides for Control of Algae and Aquatic Vegetation. A suggested alternative to the.removal of nutrients from waste dis- charges as a means of controlling algae and rooted aquatic plants is the use of selective herbicides. Considerable research on the control of algae and submersed aquatic weeds with herbicides has been conducted in irrigation and drainage canals by the Department of Agriculture. As a result of this research, herbicides have been used extensively in irrigation and drainage canals • in the Western States and by the Corps of Engineers for aquatic weed control, and have proved to be easier, much faster, and frequently less expensive than mechanical control. New and more effective selective'herbicides are constantly being discovered; many have low mammalian toxicity. Some herbicides are highly selective against a gi^en plant species and are not effective against closely related species. Moreover, some herbicides are effective in extremely low concentrations. It seems reasonable to believe therefore that it might be possible to develop safe effective herbicides for the selective control of aquatic weeds in large bodies of flowing water such as the "otomac River. Such herbicides could . be used safely and economically without damage to fish or wildlife and without impairing the value of potable water. However, these materials cannot be developed without extensive research. It is suggested therefore, that it might be worthwhile to initiate such a research program in the Potomac Basin for the development and testing of herbicides to control specific types of aquatit vegetation. ------- 20 7. Mine Drainage and Mineral Pollution. Problems of nine drainage are confined to the North Branch of the Potomac River and some of Its branches. The area affected is located in Garrett and western Allegany counties in Maryland, and in Tucker and Grant and Mineral counties in West Virginia. The streams primarily involved are the North Branch of Potomac River from its source to Westernport, Md., and 12 tributary watersheds. The larger tributaries are Laurel Run in Garrett County, Md., Abram Creek in Grant and Mineral Counties, W. Va., Georges Creek and Wills Creek in Allegany County, Md. Savage River is mildly polluted by Aaron Run in the mile above its confluence with North Branch. The UU miles of North Branch, above Westernport, are known to be strongly acid. About 50 miles of tributary streams in Maryland and West Virginia are known or believed to be seriously polluted, making a total of 95 miles of streams polluted by mine drainage. In most streams which carry mine drainage, the pH is consistently below 5 and frequently below 3 or lower. A pK of 1.8 was measured in mine drainage sampling conducted by the Federal Water Pollution Control Administration in the North Branch watershed. Insoluble yellow and reddish-brown iron compounds ("yello boy") are precipitated from mine drainage by natural oxidation and hydrolysis. These com- pounds, predominantly iron hydroxides, coat stream beds for long distances. Active as well as inactive mines are believed to contribute signifi- cantly to mine drainage pollution. In particular, Piney Swamp Run (below Masteller Coal Co. holdings) in Mineral County, W. Va., and Abram Creek are severely polluted after flowing through active surface mining areas. Elk Run, in Grant County, W. Va., is badly polluted just below the Alpine Coal Co. coalyard and some of the mines. Seepage through coal mine waste (gob) piles produces a water similar to drainage from the mines themselves. Gob is also used as an aggre- gate for road construction and repairs. This spreads the problem over the countryside. Coal dust and fines from coal washeries have on occasion been re- ported in North Branch or its tributaries. Lagoons are used to settle out the coal fines, but some fines are discharged to the air and settle out on the surrounding watershed. During heavy rainfall, these fines may be washed into the stream. Lagoons are also sometimes. constructed of gob, and seepage from them is acid. Neutralizing a stream which carries mine drainage eliminates the acid condition, but either leaves the stream with an excessive concentration of dissolved solids or produces an insoluble precipitate, depending on the alkali used to neutralize the acid. In practice, ------- 21 both conditions are likely to occur. The West Virginia Pulp and Paper Co. (Westvaco), until recently discharged, "lime mud" (lime and CaCCU) from the regeneration of process liquors, at Luke, Md. A sludge consisting of lime, calcium carbonate> -and gypsum was deposited for 15 miles' downstream, and high hardness and sulfate concentrations were measured even further downstream. . Acid conditions reduce the ve luf? of a river for most purposes. The stream bed discoloration detiacts from recreational values. Fish and other aquatic life, which are sensitive to many water impurities, can not survive. Without chemical adjustment, the waters are also unsuitable for municipal water supply and industrial use. Corrective action must therefore be taken to reduce the mine drainage, if the area is to be made suitable lor swimming, fishing, and other uses. The Maryland Department of Water Resources has recently completed an inventory of mine drainage which includes all of the Potomac Basin in Maryland. The MDWR samples acid streams quarterly, and the \ FWPCA also took two samples at the MDWR stations in 1966. Less is known about mine drainage, sources in West Virginia. The extent of mine drainage pollution in West Virginia.streams, however, was defined by the FWPCA sampling operations in 1966. Proposals have been made as .a part of the FWPCA contribution to the Corps of Engineers Appalachia Water Resources Study to inventory acid sources on the West Virginia side and to evaluate all sources in the Basin. Satisfactory methods for controlling acid mine drainage have yet to be demonstrated. The Acid Mine Drainage Pollution Control Demonstra- tion Program of the Federal Water Pollution Control Administration has established a field demonstration project near Elkins, West Virginia, where various measures to prevent the formation of acid and to control it at its source will be tested and evaluated. These measures will include air seals in underground mines, drainage diversions to keep water away from contact with sulfur-bearing forma- tions, burial of exposed sulfur-bearing spoil material, grouting to seal subsidence areas and make them impermeable, and grading and revegetation of disturbed surfaces. In connection with this field demonstration project, pilot tests of aerial survey techniques for locating acid mine drainage pollution sources are planned, as a quick and cheap tool for identifying areas of toxic spoil banks .- ' requiring special treatment. Methods of applying digested sewage sludge to neutralize and fertilize spoil banks to promote plant growth, as one solution to this problem, will be studied. At a rough estimate, there are 15,800 acres of land disturbed by mining in the Potomac Basin needing treatment to abate pollution from acid mine drainage. Of these, 11,000 were distxirbed before passage of the strip mining reclamation laws. Surface reclamation work is esti- mated by the National Survey of Strip and Surface Mining Damage to cost ------- 22 perhaps $10,000,000; plus possibly an even larger sum for treating underground mines. Seme surface reclamation work is now being done by the State of West Virginia on abandoned strip mines; and their laws prescribe bonds to take care of at least a minimum of reclama- tion on current mining operations. Some additional pollution, in the form of sediments, also results from quarrying and mining of refractory materials, sand and gravel and other minerals in the North Branch basin. 8. S ed im entat i on The Potomac River Basin discharges some 2 1/2 million tons of sediments annually into the tidal estuary at Washington. About 75 percent of this annual load originates on the watershed above the Washington Metropolitan area. A program for the control of floods and reduction in erosion through headwater reservoirs and applica- tion of watershed management practices has been proposed by the Erosion and Sedimentation Sub-Task Force, and has been incorporated into the revised Corps of Engineer's Report. They have indicated that implementation of this program could result in approximately . a 50 percent reduction in the amount of sediment carried to the estuary by the flowing river. With respect to problems of water quality, the reduction is of benefit largely to the estuary. The waters of the flowing river will continue to be highly turbid during periods of storm and surface runoff, and the use of the river and its tributaries for recreation will be affected accordingly. 9. Bacterial Pollution in the Flowing: River - Limitations on Swimming. Sampling for bacterial quality of the Potonac River waters was under- taken by the staff of the Federal Water Pollution Control Administra- . tion at 15 locations in the Potomac Basin during July, August and early September, 1966, The results of these samplings indicate that, at that time the Potomac River met both the Sub-Task Force and the State criteria for natural swimming water quality at all points between Great Cacapon and Great Falls except at Williamsport. 'The quality of the Little Cacapon and Cacapon rivers was also acceptable at this time. The quality of Town and Sideling Kill Creeks was indeterminate because there was no stream flow. In the Shenandoah sub-basins the bacterial quality at all stations, except that for the South Fork near Bentonville, Va., failed to meet either the Sub-Task Force or the State standards. The quality at Bentonville was satisfactory -jn both counts. The samples upon which the forgoing findings are based were taken at widely scattered locations during a prolonged period of dry weather, when there was no runoff, and the flow of the Potomac was the lowest on record for several of the days during this period. Thus the sampling results do not provide the data necessary to evaluate the bacterial water quality under higher flow conditions. ------- 23 This limitation is of considerable significance, because other samplings on the Potomac, by other agencies, particularly those taken regularly at the Washington Aqufiduct Water Supply intake, show that when surface runoff occurs following rain, the coliform bacteria count in the river rises well above even the more liberal standard^ originally proposed by the Sub-Task Force. This finding strongly suggests that much of the bacterial pollution in the river and its tributaries originates on the farm lands of the basin, rather than in the waste discharges of the municipalities and industries, and would continue to be present in the stream even after secondary treatment and chlorination of all wastes was accomplished. This is in line with the recent suggestion made by the staff of the Interstate Commission on the Potomac River Basin, based on their own sampling and analysis, that the bacteria found were largely of animal origin. Mr. John Henderson, a consultant for the National Institutes of Health, reached much the same conclusion in a study of the situation in 196l. The significance of the foregoing findings is that, in a normal year, when frequent rain storms might be expected, the coliform count in the Potomac and its tributaries is likely to be almost continuously above the levels currently specified for natural swimming waters. It must, of course, be recognized that these conclusions are based on samples taken at widely scattered locations, and are very general in nature. Furthermore, in so far as swimming is concerned, it can not be emphasized too strongly that the conditions which would pre- vail at any specific location can only be determined after a detailed investigation at that location, extending over a sufficient period of time to permit a full evaluation of it. It must also be clearly understood that, in addition to the bacterial sampling, the results pf which require several days in each case, a thoroughgoing sanitary survey is required at each location being considered, to insure that no untreated waste waters are discharged within the area. 10. Problems of Swimming in Small Watershed Impoundments. Plans for the development of recreational facilities in the Potomac Basin also contemplate the use of a. number of the small watershed impoundments proposed by the Soil Conservation Service for this purpose. It has generally been thought that swimming would be included among.the activities to be promoted at these sites. For those impoundments located in the agricultural portions of the basin, the problem of possible bacterial pollution from land runoff is Just as important as in the case of the flowing river. State officials of the Basin, sitting in conference with the Sub-Task Force, have pointed out that they have found it necessary on several occasions to close, for swimming, lakes similar to those being proposed, be- cause bacterial pollution exceeded the State standards. Also, in the case of lakes, the pollution resulting from land runoff, is believed to be augmented by pollution from the bathers themselves, when large numbers of persons are associated with absence of ------- circulation or flow in the water. Accordingly, each such impoundment must be evaluated separately in determining the types of recreational . activities which should be encouraged at that site. 11. Need for Further _Study_ of^Bacterial Standards for Swimming. The question of the significance of the bacterial standards now being used in evaluating natural swimming water quality, is more fully dis- cussed in Section VI on Additional Studies. The need for a re-study of these standards should be weighed in evaluating the problem of swimming in the Potomac. Also the likely impact of adoption of legal standards in the Potomac Basin in accord with the requirements of the Federal Water Pollution Control Act should be kept in mind. 12. Physical Suitability of the Potomac River for Swimming. In addition to bacterial quality,, the Potomac River must be evaluated in terms of the recommended physical standards for swimming water areas. These have to do with the clarity of the water and the condi- tion of the banks and bottom at each location being considered. In general, the main stem of the Potomac River, and a considerable portion of most of the tributaries below the forested mountain areas probably .fail to meet these standards. The waters of the Potomac during the recreation season are generally cloudy, even in dry weather when no surface runoff occurs. This is due in part to the cellular algal growths promoted by the high nutrient content of the water. As pointed out earlier, it is questionable whether this condition would, be much improved by introducing advanced treatment of waste waters for removal of phosphorus before discharge. Further research is required before a firm decision can be made on this point, however. Regarding physical characteristics other than claritys each site must be evaluated on its merits. Considerable stretches of the river are lined by muddy or rocky banks. In some places the bottom is muddy. Elsewhere it is irregularly rocky. Weed growths are prevalent in many areas. Stumps, snags, projecting rock ledges and boulders are also a hazard. In view of the prevailaing turbidity of the river, even in dry weather, these physical hazards must be carefully weighed. Each particular site must therefore be evaluated separately regarding its suitability for swimming and other recreational uses. It .should be noted, however, that West Virginia,, in addition to imposing rigid bacterial standards, does not advocate swimming in natural streams • in any case because of the obscuring hazards posed by turbidity. 13. General Conclusions Regarding the Flowing River Portion of the Basin. That portion of the Worth Branch which is affected by acid mine drainage will remain unattractive esthetically, and unsuitable for fish propaga- tion, until such time as an answer is found for the mine drainage problem. It should be entirely possible5 however, to return the remainder of the basin to an esthetically attractive condition, ------- 25 acceptable for general recreation and suitable for fish and wildlife, by provision of adequate treatment of wastes supplemented where necessary by diluting flow regulation releases from storage. In general, only limited portions of the basin are now affected by untreated or inade- quately treated wastes. What is required, however, is an organization for the accomplishment of this objective, and for the continuing surveil- ance required to keep the river clean as population increases. This is discussed in Section V, Beyond the forgoing measures, the possibility of providing a suitable swimming environment is questionable for most of the basin but in any case must be dealt with on a local, site by site basis. In so far as bacterial quality is concerned, a final answer must await the research investigations proposed in the Section VI on Policy Issues. Provision. of suitable physical conditions is also a matter of individual, site by site evaluation within the standards proposed. ------- 26 SECTION IV - THE ESTUARINE PORTION OF THE BASIN 1. Area Affected by Pollution. The tidal estuary of the Potomac extends for some 115 miles from . Little Falls to the Chesapeake Bay. In so far as water quality is concerned, howeverg only the upper fresh water third of the estuary, from about Quantico to Little Falls, presents any apparently serious problem at this time. The remaining salt water portion of the estu- ary is, in general, satisfactory for all purposes, except for minor local pollution problems in coves near some of the towns, which can readily be dealt with. Of course, if. present trends of pollution in the basin are not reversed, this situation could change, with serious consequence to the shellfish industry in the lower estuary. However, in this report discussion of water quality problems of the estuary is limited to those of the upper fresh water reach. 2. The Upper Estuary - Existing Conditions. The upper estuary presents by far the most serious water quality problem of the entire Potomac basin. It is lined on both sides for much of its length by the dense urban developments of the Washington Metropolitan Region. The water flowing into it from upstream already contains a substantial amount of plant nutrients and, during periods when surface runoff reaches the stream, has a high bacterial count and carries great quantities of silt and debris. The estuary itself is the direct recipient of domestic raw sewage overflows from combined sewers of the District of Columbia and Alexandria during heavy rains. Substantial amount of organic wastes, bacteria, and plant nutrients, in the form of nitrogen and phosphorus, are contained in the 250 millior gallons of treated sewage which is also discharged into it every day. Filth, bacteria, organic substances, trash and sediments washed from the streets, yards and roofs of the region with every storm are dis- charged into the estuary from the numerous storm sewer outfalls. This pollution is further augmented by the discharges from the numerous pleasure craft and commercial boats which traverse the area. The interplay of all of these factors results in intensive general degradation of the upper estuary. Oxygen levels are severely depressed by the biochemical oxygen demand of the organic wastes, at times causing fish kills. Explosive blooms of algae stimulated by the nutrients, case unsightly and offensive conditions, and the periodic death and decay of the algae creates a secondary organic pollution which further depletes the oxygen in the waters of the river. Accumla- tions of sediments on the estuary bottom further diminish its esthetic qualities. • At times of heavy runoff, the river also presents a muddy and unattrac- tive appearance which, because of the stirring effects of the tidal currents, persists for many days. This situation is accentuated by ------- 27 sand and gravel washing, particularly in the Anacostia Branch and in the main river at Georgetown,,which create local turbid conditions even during low flow periods when the river would otherwise be free of these pollutants. In addition to the esthetic and other detractions resulting from sewage discharges, algae, turbidity, trash, and debris, this stretch of the river at all times exhibits a coliform bacteria count well above the limits established fpr natural swimming waters. Until ways are pro- vided to reduce treated waste loads, control or treat storm runoff, control algae growth, reduce turbidity, and reduce the bacterial pollution, this reach of the estuary is not suitable for swimming and other water contact sports, and is considered unacceptable by the Public Health authorities as an auxiliary source of water supply, as has been proposed. ' Neither are the low dissolved oxygen concentra- tions adequate for maintenance and propagation of a good sport or commercial fishery. Finally, the various factors cited contribute to the general degradation of the esthetic qualities of the estuary which are essential for an acceptable environmental setting for the Nation's Capital. . 3. Existing Waste Treatment Facilities. Under Section 10 of the Federal Water Pollution Control Act, the Public Health Service, in 1957, convened a conference of Maryland, Virginia, District of Columbia and Federal officials to review the water pollution situation in the Washington Metropolitan Region. As a result of this conference, it was acknowledged by all conferees that the Potomac estuary was badly polluted, and that extensive additions and improvements to the waste treatment facilities of the region were required. Based on these findings the governmental juris- dictions comprising the region all agree to undertake the construction of facilities needed to bring all waste treatment up to the secondary or biologic'al treatment level, with the objective of achieving a BOD removal of at least 80$ from all wastes. The construction of the secondary treatment facilities called for under the 1957 agreement is now virtually complete. However, not all of the plants are functioning as efficiently as intended, and in addi- tion, the region has already outgrown some of the plants. Recent in- vestigation by the staff of the_^Federal Water Pollution Control Admin- istration indicates for example, that the Bi**e-~Elai&s Water Pollution Control Plant of the District of Columbia, through which all the District of Columbia wastes, and almost all of the wastes from the adjacent Maryland Area passes, is not functioning as effectively as intended and- is achieving a removal of only about 62 percent of the BOD. Disinfection by chlorination of the treated effluent is also inadequate during the summer months and is not provided during the winter. Since this is the ms.jor plant of the region, handling about ------- 28 . 200 out of a regional total of 250 million gallons of sewage per day, the BOD and bacterial load imposed on the river is accordingly still large. The District is now planning improvements which are designed to correct this situation, but it is quite probable that the plant will also have to be enlarged to handle the increased load caused by rapid population growth. Some of the other plants of the region, including several at Federal installations, also require improvements or expansion to meet the 1957 conference goal. The specific conditions at each of the treatment plants .of the region is set forth in the detailed inventory prepared by the Federal Water Pollution Control Administration. Additional Facilities ai)d Programs Required. Up-grading of the waste treatment facilities of the Washington Met- ropolitan region to the level required to attain an effective BOD removal of 85 percent or more, plus effective year round chlorination, will make a material improvement in the quality of the estuary, but will by no means be sufficient to achieve the objectives stated in the President's message. Additional BOD removal will be required, or sufficient dilution water provided to reduce the effects of the residual BOD upon the oxygen supply in the estuary. However, even if the BOD were completely eliminated from the waste discharges, it will still be necessary to prevent most of the plant nutrients, particularly the phosphorus, from reaching the river if the algal blooms are be be controlled. Storm water and combined sewer overflows will also require treatment and disinfection, and the seciraent load of the river reduced to manage- able proportion, and otherwise controlled. And pollution from boats must be controlled. Investigations and Studies Undertaken. A number of investigations into these various problems were undertaken during 1966 by the Federal Water Pollution Control Administration staff, both directly and with the assistance of the Federal, State, Regional and local agencies and industrial representatives. These investiga- tions are not yet all complete but most of them have progressed to the point where it is possible to give some tentative indication of the kind and magnitude of the programs required to deal with the con- dition described. The tentative findings of these investigations are' set forth in the following sections. Reduction of Nutrients for Algae Control. Of all the pollution problems of the estuary, algal blooms stemming from excessive nutrients is perhaps the most serious and presents the greatest difficulty. The result in the accumulation of large mats of ------- 29 algae which are .unsightly. The algae collect in noisome windrows on the shore, creating obnoxious condition, and their decay creates a secondary organic pollutional effect in the estuary of substantial proportions with accompanying reduction in oxygen content of the water. A principal controllable offender in this chain of events is phosphorus, the presence of which is one of the essential elements for the growth of the algae. Observations in the Chesapeake Bay estuarine system indicate that if the dissolved organic Phosphorus concentration is kept below 0.1 mg/1, nuisance algal blooms do not generally occur. Even if phosphorus is not the primary nutrient responsible for the excessive algal growths, however, it can be used as an indicator of the presence of other algal growth factors. While some phosphorus is brought down to the estuary by the .flowing river, by far the largest amount is contributed by the sewage treat- ment plant effluents. Approximately 8 tons per day of phosphorus are discharged to the estuary with these effluents, and the phosphorus concentration in the estuary reaches a peak of 5-parts per million in the vicinity of Marbury Point. This is 50 times the 0.1 ppm believed to be the desirable upper limit of phosphorus concentration. Phos- phorus concentrations above 0.1 ppm extend generally from Theodore Rosevelt Island to below 'Quantico. The area of undesirable algal blooms extends from Memorial Bridge to Quantico. Phosphorus is not normally removed from sewage in significant quantities by the usual secondary treatment process. Other means must be found, therefore, for either preventing it from reaching the estuary, or of reducing its concentration after it reaches the estuary, if the algae blooms are to be controlled. This may be done by one or more of the following ways: (a) dilution of the wastes by stream flow regulation, (b) diversion of the treated wastes out of the basin, and disposal thereafter by any of several possible ways, (c) diversion further down- stream to dilute the wastes in the larger area of the lower estuary, (d) renovation and recircultion of the waste waters for direct re-use, (e) additional treatment specifically to remove the phosphates, (f) dilution after tertiary or advanced treatment, and/or (g) a combi- nation of methods. All of these alternatives were investigated. In doing so, the possi- bility of using the upper estuary as an auxiliary water supply for the Washington area was kept in mind, and the probable effects of such diversion upon the utility of the estuary for this purpose was determined by systems analysis methods, using a mathematical model. 6 (a) Dilution by Flow Regulation. Analyses and computations indicate that, while substantial amounts of flow regulation storage were pre- viously recommended in the 1963 Corps of Engineers report for the purpose of maintaining the organic waste assimilation capacity of the estuary, no reasonable quantity of seasonal flow regulation releases from upstream storage is capable-by itself of lowering the total dis- solved phosphorus concentration in the critical section of the upper ------- 30 estuary to or below the desired 0.1 mg/1 level. This vould be true regardless of the level of phosphorus concentration in the incoming water. In view of this find-ing, reliance on flow regulation as the principal means of reducing che phosphorus concentration in the estuary is not feasible. As indicated below, however, some flow regulation can be used in combination with other processes and alternatives as a means of controlling the dissolved phosphorus concentration level in the er.tuary. 6 (b) Diversion Out of the Basin. With respect to diversion of the wastes out of the estuary, four methods of disposing of them after diversion were studied. These are (l) disposal in the Atlantic Ocean, (2) disposal in Chesapeake Bay, (3) injection into underground strata and (h) disposal by surface spreading and irrigation. Pre-requisite to all but the first is the requirement that the wastes' first be given a high level of secondary treatment. For ocean disposal, a lesser degree of treatment plus chlorination might be sufficient, but specific investigation and study would be required for confirmation. 6 (b) (l) Disposal to the ocean is by far the most costly of the alternatives, with estimated capital costs of $350 million and annual operating costs of $16 million. On costs alone, this alter- native must at least for the present, be ruled out. It is, however, engineeringly feasible, and does provide a possible long term solution to the algal problem-. 6 (b) (2) Disposal in the Chesapeake Bay appears to be the least costly of the four alternatives. Capital costs are estimated at about $100 million, and annual operating costs, mostly for pumping, at $2 million. While, as pointed out below, advanced treatment, for removal of nutrients, is cheaper then disposal to the Bay, the costs are sufficiently close that this solution should not be ruled out on costs alone. But when possible effects of such discharges upon the Bays as well as upon the Potomac itself, not yet fully understood, are taken into account, it becomes apparent that this solution would . require a great deal more study before a firm decision to adopt it could be made. Possible detrimental effects upon the ecology of the Bay, coupled with the probability that the algal bloom problem would merely be transferred to a number of square miles of the bay surround- ing the end of the outfall pipe, with attendant esthetic nuisance problems, suggests that, within the forseeable future, the Bay would be just as unacceptable as the Potomac River as a sink for nutrient rich wasters. 6 (b) (3) and (U) Alternatives (3) and (U) are intermediate in costs. Injection into the ground would involve an extensive field of some 300 wells spread over some 20 'square miles of Southern Maryland, at an estimated capital cost of $120 million. For the spreading and irriga- tion schenes, land areas required would vary anywhere from 6 to 100 or more square miles depending upon the arrangement, and cyclical ------- 31 . timing of whatever operation was found most feasible. Capital costs are estimated at about $1^0 million. For both alternatives annual operating costs, mostly for pumping, would also be high, with the injection scheme showing the higher cost. While there are a number of technical draw-backs to both of these schemes which must be re- solved before either of them could be adopted with confidence, it .would appear that, for the purposes of this study, they must also be disgarded in favor of the less costly alternative of advanced treatment, which, in addition to removing some 90 percent of the phosphorus from the waste effluents, would, by further-reduction of other contaminents, also make the estuary more suitable as an auxiliary water supply for the Washington region. The schemes described above for diverting waste waters from the estuary have been rejected primarily on the grounds of costs. How- ever, in addition to costs, other factors mitigate against diversion. The removal of 250 million gallons per day (present sewage discharge) and ultimately of perhaps one (l) billion gallons per day of fresh water from the upper estuary during periods of extreme dry weather when there is little direct flow from the river, could cause an undesirable ecological imbalance which might have an adverse effect upon the finfish and shellfish resources of the estuary. This possi- bility should be carefully examined before any decision to divert so much fresh water from the estuary is agreed to. Secondly, as dis- cussed below, diversion of the waste waters at times of extreme low . flow would cause a salt water incursion to such a degree that the upper estuary could not be used as a source of water supply. For these reasons also, it appears desirable to deal with the waste water disposal problem within the confines of the basin. 6 (c) Diversion of Wastes to the Lower Estuary. Diversion of the wastes to the lower estuary is roughly comparable in cost to tertiary treatment, with capital costs estimated at about $62 million. Like diversion to the Bay, however, it would simply mean that-the algal bloom problem would ultimately be transferred to that area. In addition, the effects upon the ecology of the lower estuary are unknown, and the advantages of using the upper estuary as a possible auxiliary water supply would be lost because of probable salt water intrusion. Accordingly, while some diversion to the lower portion of the upper estuary will be required, as described below, in con- junction with both advanced treatment and flow regulation, diversion to the lower, salt water estuary as a separate solution to the problem has also been rejected. 6 (d) Renovation of Wastes and Re-circulation for Direct Re-Use. Another alternative means of removing the wastes from the estuary is that of recirculation for direct re-use of the waste water after appropriate treatment. Direct re-use is technically feasible. How- ever, it must be emphasized that a variety of special precautions would have to be taken at this time in order to order to provide complete and absolute assurance of safety in using the water so produced. The Public Health Service Drinking Water Standards state ------- 32 that "Drinking water shall not contain impurities in concentrations which may be hazardous to the health of the consumers . Substances which may have deleterious physiological effect, or for which physio- logical effects are not known, shall not be introduced into the system in a manner which would permit them to reach the consumer." Thus, -at this stage of development of the processes involved, significant "over-design" would have to be incorporated along with a variety of fail-safe controls and detailed analytical monitoring. These require- ments, controls, and monitoring services can be accomplished but at higher costs than will be possible after the completion of research and development studies now underway. In addition, it must be remembered that the substances removed from the. waste water must be disposed of outside the estuary area, if the.estuary is to be made suitable for the other contemplated uses. This would involve additional costs. At this time, economic rather than technical 'considerations are likely to be more of a limiting factnr in determining the feasibility of renovating wastewater for pub Lie water supplies in any given situation. Since it is anticipated, however, that renovated water will, for reasons of cost, always be blended into an existing water supply from a con- ventional source when available, renovation would not be a completely separate solution. With respect to applicability of waste water renovation techniques to the effluent from the Water Pollution Control Plant of the District of Columbia, the above general statements would hold true. Clearly, how- ever, the actual process sequence involved, the operating conditions, the degree of over-design, the method of reintroducing the renovated water into the water supply distribution system, the method of dis- posing of sludges, etc. , would all have to be examined in a detailed engineering survey at the specific site and the specific situation before reliable cost estimates for such system could be made. Costs of producing water by this scheme would approximate 17 cents • per thousand gallons, about three times, that of providing advanced treatment of the waste waters before discharge to the upper estuary, where they could be used as a possible auxiliary raw water supply source. After due. consideration _of the forgoing factors, the Sub-Task Force believes that there is no inherent benefit at this time in direct re-use over advanced waste treatment and discharge to the upper estuary for possible use in an emergency. Also,, the fact that such a process would be required for only part of the year would mean that there would be an economic loss in that during the remainder of the year the river would supply all needed water and the extra treatment processes would remain idle. ------- 33 Direct re-use would also cost more because of the necessity of con- structing pipelines from the waste treatment plants to. the water supply system intakes at Dalecarlia and. elsewhere, or constructing additional small water treatment plants near the waste treatment plants. Use of the upper estuary would partially eliminate the need for these pipelines or additional treatment plants, since the estuary would serve the pipeline's purpose. In the latter case, treatment costs would also be less than for direct re-use, since the natural purification ability of the upper estuary could be used, and accumulated excess flows from upstream would not be lost. It also must be assumed that from the public health standpoint as well as from an esthetic point of view, as long a time period as possible between the time the waste is discharged and the time it is put into the water distribution system is desirable. The use of the upper estuary plan would give a 3 to 8 day time interval, while there would be essentially no time interval with direct re-use, Because of the above considerations, direct re-use was not considered further. 6 (e) Additional Waste Treatment for Removal of Phosphorus. At the request of the Sub-Task Force, staff of the Federal Water Pollution Control Administration during 1966 investigated the possibility of removing a substantial portion of the dissolved phosphorus from secondary treatment plant effluent. The results of this investiga- tion indicate that it is possible to accomplish this objective within reasonable costs. The studies indicate that 90 percent of the phos- phates may be removed by a coagulation and precipitation process involving application of lime and iron salts to the secondary effluent in a terminal sedimentation basin. -Cost of the process, based on the large volumes to be treated at the Blue Plains Plant, are shown in the following table. For the smaller plants of the metropolitan region, the unit costs would be higher. Total Cost of Removing Phosphates in Cents/1000 Gallons 250 meed 350 mgd mgd Capital Amortization Operating and Maintenance Cost of Chemicals Lime Iron Salt Cost of Sludge Disposal by Barging to Sea Total Cost Savings when Recalcining of Sludge in Use Total Cost with Recalcining 2.18 2.18 ------- It is assumed that 90 percent of the phosphates would be removed by the lime treatment discussed: above. 6 (f) Dilution of Residual Phosphorus by Releases from Storage. As indicated above, tertiary treatment would remove about 90 percent of the dissolved phosphorus in the sewage effluents, leaving a phosphate content of 0.5 ppm in the effluent as discharged. However, the whole Chesapeake Bay System is, and apparently always has been, an enriched body of water, with a present background phosphate content of about 0.05 ppm, which is one half the allowable maximum if algae blooms are to be controlled. The waters discharged to the estuary by the Potomac River have an average annual total phosphate content-several times the maximum allowable, but much of this is bonded to soil particles and is not available for algae growth. The phosphorus content, during dry weather when sediments are absent, drops to below 0.1 ppm, thus further diluting the phosphorus discharged to the estuary in the sewage effluents. It appeared, then, that if sufficient dilution water could be made available from upstream storage facilities during periods of high algae growth, the nutrient content of the estuary might thereby be reduced to acceptable levels. Further investigations along these lines revealed, however, that while some improvement could be achieved through additional dilution, complete correction of the situation, based on 1985 conditions, could not be achieved by this means. Additional-remedial measures are required. 6 (g) Multiple Attack Methods. Optimization studies by staff of the Federal Water Pollution Control Administration indicate that a combination of advanced waste treatment, flow regulation releases from upstream storage, and diversion and dispersal of treated wastes through multiple outlets for some miles along the lower portion of the upper fresh water estuary could be expected to accomplish the the desired objective. This does not mean that the estuary would be entirely free of algae. As noted, the estuary and the Bay already have a relatively high background phosphorus content. During warm weather, the plankton growth in the rich waters of the Bay and estuary.is already sufficient to reduce visibility in the water by a substantial amount. Little, if anything, can be done about this situation. But it is believed that the remedial measures cited above would prevent the unsightly and noisome mats of .algae, now so troublesome, from accumulating. Presented in the table following are the results of these investigations, They are based on the 1985 projections of population, water supply requirements and waste water discharges which were used in the 196"3 Corps of Engineers report. It should be noted that the required releases decrease as diversion is increased. The least cost com- bination would require from- 600 to 1000 cfs of flow releases from upstream impoundments plus 250 mgd of diversion at a time when total waste discharges would amount to 350 mgd. ------- 35 For 19o5 conditions, lesser amounts of diversion and dilution would • apparently be required, with indications that one or the other alone might be sufficient. However, more refined studies will be required before a definitive decision can be made on this point. ------- POTOf( ESTUARY . . ALTERNATE SYSTEMS FOR WATER QUALITY CONTROL Based on 1985 Projections .and 85% BOD Removal by Secondary Waste Treatment (Preliminary Results) - • System Annual Treat. - % Diversion- Add. Cost. removal of MOD Flow Release phosphorus cfs . x 10 " 1 . 2 3 U 5 6 7* 8* 9* 10** 11 0 90 90 90 90 90 90 90 90 90 90 0 0 0 o .0 0 93 120 180 250 * 250 0 0 0 5.6U 500 6.5 • 1000 „ 7.7 v 1500 . 9'. 8 ;: 1870 12.6 1870 lU.l 1500 11.7 ' • ,1000 . 10.5 600 - 10.6 500 10. If; Miri. - Max. DO Total P mg/1 . mg/1 1.3 1.71 3.8 . 0.25 U.O . . , .. 0.22 . 1*.5 , 0.18 i».-9 ' 0.15 5.2 0.13- 5.1 0.10 5.2 0,10 "., 5.U. 0.10 5.3 0.10 5.0 0.13 * Systems which produce desired quality results. ** Most economical system which produced desired quality results, o\ ------- 37 7. Further Reduction of BOD for Control of Oxygen Depletion The discharge of organic wastes to the estuary5 together with organic pollution caused by decay of masses of algo.e, now causes a serious oxygen depletion in the estuary, with attendant fish kills on occasion. Treatment of all wastes to remove at least 8>5% of the organic substances (BOD), would do much to ameliorate this situation, but would not com- pletely correct it. The 19&3 report of the Corps of Engineers indicated that releases from storage in Seneca Reservoir sufficient to maintain a flow into the estuary at all times of about HOOO cfs were therefore re- quired in order to maintain an acceptable oxygen level in the estuary. These figures were based on studies by the U. S. Public Health Service for 1985 conditions. The program for tertiary or advanced treatment of sewage effluents for phosphorus removal, recommended in the preceeding section, if adopted, would have the added advantage of also removing about 50 percent of the BOD remaining in the waste discharges after secondary treatment. With this additional reduction in BODS it is believed that the oxygen deple- tion problem in the estuary would be largely corrected. Under these circumstances, releases from storage for flow regulation for control of . Organic pollution in the estuary under 1985 conditions would not be needed. For the year 2010 conditionss however', some releases for BOD control might be required. If so the releases for dilution of phosphorus might be adequate. However., additional • studies of conditions to be expected after 19^5 should be undertaken before final decision on the need for such releases are made. It is observed, however, that the much smaller volume of flow regulation releases required for dilution of nutrients up to I9o5 might be provided from some of the more remote upstream reservoirs proposed. If so, storage in the proposed nearby Seneca reservoir for flow regulation would not be required. Mechanical methods of re-aeration have also been proposed as a means of maintaining desirable oxygen levels in the estuary. Some preliminary investigations by staff of the Federal Water Pollution Control Admini- stration indicate that such a process might cost from _26o to h60 dollars per ton of dissolved oxygen added to :the water, depending on depth, and size of operating unit. Application of the process to the Upper Estuary would require considerable study and investigation, because of the complex character of the estuary and its currents. The Sub-Task Force has not been able to pursue this problem any further and there- fore has no basis upon which to make economic comparisons with other solutions. It is observed, however, that the suggested solution to the nutrient problem would probably make it unnecessary to give further consideration to mechanical re-aeration. 8. Elimination of Pollution from Combined and Storm Sewer Overflows The provision of complete treatment and disinfection of all waste waters discharged from the sanitary sewers of the metropolitan area ------- 38 vill not completely eliminate the discharge of polluting substances into the upper estuary. About 15,000 acres in" the District of Columbia and a much smaller area in Alexandria are served by combined sewers which carry both storm water and domestic sewage. During dry weather, the flow from the sewers is normally all carried to the treatment plants for processing before discharge to the river, provided the overflow regulators are functioning properly. During rainy weather, however, that portion of the mixed storm water and sewage flowing in the combined sewers which is above the capacity of the interceptor sewers leading to the treatment plant to carry is by-passed directly to the river, thus carrying a considerable volumn of raw sewage with it. Up to now the only practical means of correcting this situation has been to construct separate sewers to replace the combined sewers. The District of Columbia has been spending from 1 to 2 million dollars per year on this program but reports that it will require about $350 million and many years to completely eliminate the combined sewer overflows by this method. Alexandria has so far done little to eliminate its com- bined sewers. Research and investigations into other methods of dealing with combined sewer flows are now under way including study and demon- stration of holding tanks and other devices. Storm water alone also carries considerable amounts of pollution to the river. Studies of storm water quality conducted by the Public Health Service in selected urban areas indicate that the storm water runoff from the average urban area contains substantial amounts of BOD. Fecal coliform and fecal strepticocci bacteria are also present in numbers indicative of a high degree of pollution. Thus, storm water, by itself, is indicated to be a serious source of river pollution. When combined with the raw sewage overflows from combined sewers, these flows become even more contaminated and carry even greater amounts of organic and bacterial pollution. Discharge, of untreated storm water into the estuary is therefore a serious, if intermittant, deterent to swimming and water sports, and seriously reduces its esthetic quality. The only apparent solution to the storm water and combined sewer over- flow problems, at the present time, is collection, treatment, and chlorina- tion of these flows before discharge. Treatment should probably include some form of coagulation and settling in a detention basin if a satis- factory quality is to be achieved. Such impoundment and treatment would also reduce the heavy loads of sediment, trash, and turbidity carried into the river by storm water but disposal of the accumulated materials would present a problem of considerable magnitude. The volumes of storm water which must be dealt with in a metropolitan area such as Washington at times of heavy rainfall, are very large. For intense storms, total volumes on the order of 6 billion gallons are involved. The collection, impoundment, and ultimate treatment and chlorination of such volumes presents substantial construction and operating problems. Very rough estimates based on extremely sketchy information and computations indicate a total cost for the necessary ------- 39 works on the order of $2 billion. A serious problem, however, is that of finding suitable sites for the required detention basins or other facilities. For example, at 10 feet depth, a total of some 1,500 acres of detention basins on the District and Maryland side, and some 500 acres on the Virginia side of the River would be required. A total of about 1^0 potential sites where facilities might possibly be constructed have been identified. Provision of suitable treatment facilities to handle storm water over- flows would, of course, also eliminate the need for separation of storm and sanitary sewers5 since combined sewer overflows could be detained and treated along with the storm sewer discharges. Sludges and sedi- ments collected in these facilities would, of course, need further treatment. If" total storm water is not to be dealt with, however, 'then some means must be found to deal with the combined sewer flows . alone. Methods of dealing with storm and combined sewer overflows are now being studied and demonstration grants are being made available by the Federal Water Pollution Control Administration for design and construction of various pilot and experimental types of facilities for dealing with this problem. Research and development is only in its earlier phase, however, and practical solutions to this whole problem must await further effort. Until then, the upper estuary of the Potomac will continue to receive large and possibly increasing, amounts of organic,bacterial and other polluting substances with every storm. 9. Sediirientat i on The Potomac River presently discharges into the upper estuary about 2 1/2 million tons of sediments annually. Some 75 percent of these sediments originate on the watershed upstream from the proposed Seneca Dam site. Most of the remainder come from the Washington metropolitan area, which comprises only about 2 percent of the watershed. These latter sediments are produced largely by erosion from subdivision, highway and other construction in the urban and suburban areas. The Erosion and Sedimentation Sub-Task Force, in a statement.prepared for the Water Quality Sub-Task Force, states that their recommendations include provision of technical and financial assistance to States, local organizations and landowners and operators to install sedimenta- tion and erosion control measures on the watershed, including a large number of headwater reservoirs. The recommendations also include pro- visions for erosion control in urban and suburban areas, including 800 sediment detention basins together with mulching, seeding, sodding and other practices. The entire program is expected, when completed, to reduce the current rate of sedimentation in the estuary by about ^5 to 50 percent. Some further reduction of sediments reaching the estuary can be expected., however, d~;e to the trapping effect as additional ------- Uo reservoirs are installed. On this score, it should be noted that a dam of sufficient size at Seneca would, trap almost all of the sediments originating above that point. The Sub-Task Force indicates„ however, that while it recognizes that from a water quality standpoint further reduction in the sediment load is desirable, they feel that, due to physical, economic, and institu- tional considerations, it is not feasible at this time to attempt to develop additional measures which might be able to further reduce ero- sion and sedimentation. The recommendations of the Sedimentation Sub- Task Force are set forth in more detail in their report. •The present rate of sediment deposition in the upper estuary now re- quires annual dredging to maintain the navigation channels in the Washington area. Much .of this dredging could be eliminated if Seneca Reservoir were constructed and erosion control practices at construc- tion sites in the metropolitan area instituted. To gain some idea of the relative costs involved, the Water Quality Sub-Task Force requested the Corps of Engineers to develop the alternative costs of dredging versus entrapment of the sediments in a Seneca Reservoir. Thes.e costs are set forth in the following tables. ------- ESTUARY Sediment Inflow to Estuary from from 1. 2. 3. U. 5. 6. 7. Seneca tons/yr 2,100,000 1,130,000 730,000 590,000 1(8 0,000 380,000 250,000 Local Areas Total tons/yr tons/yr 263,000 263,000 263,000 263,000 263,000 263,000 263,000 2,363,000 1,393,000 993,000 853,000. 7 to ,000 6U3.000 513,000 Cost for Dredging $/torT 3.00 3.00 3.00 3.20 3.^0 3.75 3.75 Annual Dredging Cost $ 7,090,000 U, 180, 000 2,98n.ooo 2,730,000 2,530,000 2,UlO§000 1,930,000 Annual Cost Seneca * 0 1, 1(80,000 ' 2.non,000 2,350,000 2,680,000 3,090,000 3,850,000 Total Annual Cost for Annual Sediment Removal Cost $ $/ton 7,090,000 5,660,000 ^,980,000- 5,080,000 5,210,000 5,500,000 5,780,000' 3.00 2.70 2.37 2.1*2 2j48 2.62 2.75 .fc- H ------- SENECA RESERVOIR 1. 2. 3. i*. 5. 6, 7. Sediment Storage hfYj, 0 63,000 89,000 98,000 105,000 112,000 120,000 Settling Pool Storage JUF. 0 90,000 200 juuO 300,000 1(00,000 550,000 92,000 Surcharge _JbI^_., 0 183,000 •l6.-j,000 183,000 1.83,000 183,000 183,000 Total Storage _JU£.__ 0 336,000 1*72,000 581,000 688,000 8^5,000 . 1,223,000 Total Cost $1000 _JL 0 29,500 Ho, ooo Vr,ooo 53,500 61,800 77,000 Average Annual Cost $1000 ^ $__ 0 1,1*80 2,000 2,350 2,680 3,090 3,850 Trap Eff . of I" 0 1*6 65 72 77 82 88 Sediment Trapped by Reservoir Tons/yr 0 .970,000 1,370,000 1,510,000 1.620,000 1,720,000 1,850,000 Sediment Passed to Estuary Tons /yr . 2,100,000 1,130,000 730,000 590,000 .1*80,000 380,000 250,000 ro ------- 1*3 The least cost method of dealing with the annual load of sediment deposited in the estuary is shown to be a combination of dredging and detention in Seneca Reservoir. However, the savings in cost over that of dredging alone is only about 20 percent. It is quite likely therefore that the detriments and social costs associated ; : with constructing a single purpose Seneca Reservoir as a sediment trap would be considered as jmore than offsetting this small saving. Of course, if a multiple purpose reservoir at Seneca were constructed, its use as a sediment trap, might be placed in a much more favorable light. . The reduction of sediment originating in the metropolitan area will require that the States and the local governments of the region adopt and enforce appropriate statutes and ordinances requiring the application at construction sites, of the detention and surface runoff control measures proposed by the Erosion and Sedimentation Sub-Task Force. For the long run, a.far more serious effect of sedimentation in the upper estuary is the gradual shoaling of this water body. For over 150 years, dredging operations have had to be undertaken periodically to eliminate the mud islands and shoals which have from time to time appeared. Thus, East and West Potomac Parks, Boiling Airfield, the National Airport, and the Virginia approaches to the lUth Street Bridge have all been built up with material dredged from the estuary. This shoaling can be expected to continue, although at a much slower pace if the measures proposed above are adopted. Extensive reaches of the upper estuary on both sides of the channel, for a number of miles downstream from the Memorial Bridge, have been filling with sediments over the years until the water is now only from one to four (l to H) feet deep. These areas are of little value today for navigation, either by pleasure or commercial craft, and in a few years will be altogether useless. Estimates by Drs. Wolman, Geyer and Pyatt, in their 1957 report to the Interstate Commission on the Potomac River Basin, indicate that, at the present rate of deposition, the estuary from Chain Bridge to Fort Foote will be completely filled in less than 50 years. 1t Salvaging of the upper estuary for navigation, recreational boating and preservation of the general esthetic environment of the city will require the annual dredging of one or two million tons of sediments per year, and in addition, the removal of some tens of millions of tons of sediments which have been accumulating in the shoal areas over several decades. This is a large and costly program. One of the most serious problems involved is that of where to dispose of this larf.e volume of dredged material. The Metropolitan V.'ashington Council of Governments, through its Regional Sanitary Advisory Board and a firm of consulting engineers, is now ------- engaged, in a study of the solid wastes disposal problems of the region. This study vill include a more detailed analysis of the dredging and disposal of these accumulated sediments, including estimates of the costs of doing so, and some indication of possible disposal sites. The report on this study, when completed, should throw more light on this difficult problem. 10. Turbidity At times of storms, the waters reaching the upper estuary of the Potomac will present a dis'colored and muddy appearance in spite of all that can be done to control erosion and sediment transport. This condition is due to the nature of the Piedmont soils from which the sediments are derived. The very fine particles of the soil do not settle readily and are carried past the detention structures. The result is that, even with excellent sediment control, the effluent, while containing very little actual sediment, is still muddy in appearance. Upon reaching the estuary, this turbidity persists for days because of the stirr- ing action of the tidal currents, and even extends into the lower estuary. If the estuary is to be made at all times suitable esthetically and physically for swimming, general recreation and environmental improvement, additional measures will be required to deal with this persistent turbidity. Polyelectrolytes have been proposed for this purpose. These coagulant aids consist of synthetic compounds with a. very high . molecular weight. When applied in relatively small amounts, they promote the agglomeration and settlement of suspended material not previously removed. On the scale proposed, this process is as yet untried. A recent test application of these substances in the Rock Creek watershed substantiates the belief, however, that this procedure might provide a feasible means of clearing the estuary when needed. The Rock Creek experiment is being continued by the Dow Chemical Company,makers of the poly- electrolytes, in cooperation with the Maryland National Capital Park and Planning Commission. Estimates prepared for the Water Quality Sub-Task Force by the Dow Chemical Company indicate that application of polyelectrolytes to the Potomac Estuary over a four month recreational season would cost somewhere between 1 and 1-1/2 million dollars per season. If polyelectrolytes are to be applied, it is most essential that the nutrients which promote the growth of algae in the.estuary also be removed. If this is not done, the increased penetration of sunlight permitted by the clearer water could cause a great increase in algal growth. In fact, the resulting cloudiness and unattractive appearance of the water which would presently . occur as a result of the increased algal growth would probably be worse than that for which the electrolytes were used. There- fore, unless the nutrient problem in the estuary is adequately ------- dealt with, there would be little point in trying to clear up the suspended sediments. The effects of the settled fine sediments upon the bottom life of the estuary would probably also require investigation. Large quantities of sand and gravel are dredged from the upper estuary, expecially along the Maryland shores. Much sand and gravel is also mined in or near the streams discharging into the .-.• tidal portion of the Anacostia River. The washing of these important construction materials results in considerable turbidity and creation of a muddy appearance in both the Anacostia and the Potomac. This condition would also require correction if turbidity is to be eliminated. One possible approach to this problem would be to re- quire these sand and gravel companies to treat their wash water with polyelectrplytes in order to cause the sediments to settle quickly. Some research and experimentation'would probably be required, but, on the assumption that a suitable technique could be developed, this requirement might be made a condition of licensing these operations9 under the State water pollution control laws. 11. Effects of Accumulated Sludges and Bottom Muds. The upper estuary, for some distance above and below Blue Plains, was believed to be covered with a-blanket of sludge and sediments, resulting from the discharge into the river over a long period of time of large quantities of untreated, or partially treated wastes, inter-layered with the sediments brought down from up river. These deposits cover about 10 square miles. It was thought that the up- • take of oxygen by these deposits 'placed an additional burden on the oxygen content of the river, in the slow process of bacterial digestion and conversion to inert material. Measurements and study of these deposits were therefore undertaken by the Federal Water Pollution Control Administration in October, 1966. This was accomplished by means of a series of. core samplings taken at intervals over the 13 mile reach from Marshall Hall to the mouth • of the Anacostia. In general, these samples showed that the deposits are mostly muds and silts, interspersed with thin layers of what appear to be de- composed sludge. The evidence of sludge was fairly well confined to the eastern side of the river from the Naval Research Laboratory Dock downstream to Oxon Creek. Sludge banks, of 6 inches to 1 foot depth were, however, found on the top layer of the deposits only in the vicinity of and downstream from the Blue Plains treatment plant. From these observations it can be tentatively concluded that no extensive sewage sludge deposits were evident in the area sampled, at the time of sampling. This cruise was made after a month in which abnormally high rainfalls had been recorded, and some flushing, as well as deposition of new alluvium, may have occurred. It would appear from this reconnaissance survey that sludge deposits ------- as such are nowhere near as extensive as at first thought. The effect of these deposits on the oxygen of the river was determined, and is incorporated into the calculations. It appears that physical removal of the sludges should not be necessary but final decision should await completion of improvements in treatment of wastes at the Blue Plains Plant. If a decision is made to dredge the shallower areas of the estuary to improve their utility for boating as discussed in (9) above, the prob- lem of what to do about the sludge deposits will, of course, have been largely solved. 12. Pollution from Boats and Marinas. The volume of wastes discharged from vessels, boats and marinas is rapidly increasing and adds 13 the Nation's pollution problems. • Most recreational craft have no-waste treatment facilities. Galley and toilet wastes are discharged directly into the water, giving concern to public health and pollution control authorities, conser- vationists, and the boat and marina industries themselves. Boating is, in effect, degrading the v;-ry waters needed to maintain it. This is particularly true of the Chesapeake Bay and the Potomac River in the Washington, D, C. area, one of the fastest growing communities in the United States. A number of marinas line the shoreline of the Potomac in the vicinity of the District of Columbia. At the Columbia Island Marina, in the Pentagon Lagoon, 665 boats are berthed. It is one of the largest powerboat marinas on the "east coast. It is owned by the National Park Service and run by Government Service Inc. for the public. For the sailing-only sailor there is the Washington Sailing Marina down- river toward Alexandria, under the same Government Service management. Other clubs or•Yacht basins include the Fort McNair Yacht Basin, the Old Town Yacht Basin, the Capital Yacht Club off Mai^Avenue and the • biggest and newest of the local boating places, the Thompson Boat- house run by the National Park Service. . Sanitary facilities are inadequate at most of these installations and the sanitary conditions of the environment are deplorable, with no regulations governing the discharge of wastes from boats. This is particularly true at the Pentagon Lagoon, Fort McNair Basin and the Capital Yacht Club, where some people live aboard their boats all year long. Since these installations are on government property and leased by the Government to operators, they will come under the Federal Water Pollution Control Act, Sec. 11, covering the Control of Pollution from Federal Installations. The elimination of pollution from boats and marinas requires appropriate pollution control facilities. To date 27 States have enacted boat sanitation laws and some 15 States have legislation pending. The States of Virginia and Maryland are among those which have reviewed and are considering adoption of the Rational Association ' of State Boating and Law Administrators "Model Law". However, treat- ment devices which merely macerate and chlorinate sewage discharges ------- from boats are not considered, acceptable by many State officials. The District of Columbia and the State of Maryland do not consider them acceptable in their present stage of development. Washington, D. C. and Alexandria, Virginia are navigable ports and vessels using these ports may be coastal or transoceanic. Effective control of such vessels including our own Navy vessels will have to be done under Federal regulations, not State regulations. Water pollution problems caused by boats and marinas will continue to grow in size and complexity if steps are not taken in the immediate future to control them. Sanitation.is a prime factor in boating en- joyment and it is important that the boating industry and local, States and the Federal Governments work-cooperatively toward this common objective. Attainment of this objective would require measures to (l) protect the water resource by collecting and treating the discharges of galley and body wastes from pleasurecraft and marinas, (2) conserve the water resource for legitimate uses through pollution abatement measures for boats and marinas, and (3) provide technical leader- ship and guidance in the planning and development of programs relating to control of boat and marina pollution, including the collection, evaluation, and dissemination of necessary and. usable data to Federal, State, and local agencies, industries, and other . interested organizations. To be effective, the measures and regu- lations promulgated by Maryland, Virginia and the District of Columbia should be uniform. 13. Bacterial Pollution and the Problem of Swimming in the Upper- Estuary The bacterial count in the upper estuary is at all times above the standards for natural swimming waters imposed, by the State health departments. This bacterial pollution comes from a variety of sources. The elimination from the estuary of all untreated and un- disinfected waste water discharges, plus treatment and-disinfection of discharges from all storm and combined sewers and all boats and marinas would do much to correct this situation but would be an expensive program involving expenditures which, within the present state of knowledge regarding waste treatment methods, might cost well over 2 billion dollars. But even^with completion of this expensive program, it is highly questionable whether the bacterial count would be reduced to accept- able figures. In addition to vessels in transit which might on occasion also discharge untreated wastes, considerable pollution would still find its way into the upper-estuary from every branch, ran and creek emptying into it. Studies on Rock Creek revealed the existance of numerous small outlets which were discharging liquids of questionable quality and unknown origin, and bacterial counts were above acceptable levels, even in dry weather. Studies by the John's Hopkins University on Jones Falls and Herring Run, in Balti- more, Md., show that these urban streams, flowing through a city which ------- .has no combined sewers, nevertheless contains a certain amount of untreated, domestic sewage of unknown origin. These discharges are probably the result of illegal and surreptitious connections of sanitary outlets to storm sewers, direct discharges to the creek from old and long forgotten private sewers and from small residential developments, or leakage frotf interceptor and trunk sewers. Sewers can leak outward as well as inward and an early report by the Public Health Service indicates that in years past the interceptor sewer in Rock Creek was leaking wastes to the stream. This general situation is probably characteristic of all urban streams, and is-the penalty we must pay for the dense urban occupation of their drainage basins. In the Washington Metropolitan region, it can be ex- pected that every stream in the area, including, for example, Cabin John Branch, Four Mile Run, Piraraits Run,Spout Run, Donaldson Run, Northwest Branch and others, would, on careful inspection probably show this same polluted condition. A detailed and costly sanitary survey, including interior inspection of many homes, would be required to correct such conditions. Chlorination of ever;/" stream might also . be required. Beyond these sources of pollution, however, direct run- • off from the urban land itself, adjacent to all water courses, would also bring with it a certain amount of pollution. As long as the conditions described above prevail, health authorities would in all likelihood be unwilling to approve -the metropolitan reach of the Upper Estuary as a suitable place for swimming, on the grounds that it did not meet requirements of the Sanitary Survey. This'con- clusion is in line with the water quality criteria proposed by the Interstate Commission on the Potomac River Basin in 1956, which were based on the view that attainment of swimming water quality in the Metropolitan section of the Upper Estuary was questionable. The report of the Subcommittee on Science, Research and Development of the House Committee on Science and Astronautics, 89th Congress, on Page 29, summarizes this whole complex problem of .swimming water quality in urban surface waters as follows: "Swimming and water contact sports in urban surface waters would seem to be an expensive and distant possibility." The Water Quality Sub-Task Force is in agreement with these conclusions and suggests that a great many very fine swimming pools, with sand beaches and other amenities, might be built for far less than the cost of trying to reduce bac- terial pollution in the upper estuary to a level which would meet any reasonable bacterial standard for natural swimming waters. Use of the Bstuary for Emergency Water Supply. Previous discussions indicated that, with the.construction of the recommended treatment facilities, it should be possible to use the upper estuary as an auxiliary water supply during emergency conditions. Such conditions would prevail during prolonged droughts when river flow was low, and there was little if any surface runoff. Under these ------- 149 conditions, the quality of the water at the upper end of the estuary would probably be little different from that of the river above the water supply intake9 and should therefore prove suitable as a raw water source for an emergency supply. Recirculation .in the estuary, would quickly destroy this condition, however. ^ These acceptable conditions vould not prevail during storms. The estuary would then receive large quantities of raw sewage discharged with the overflow from the combined sewers, as well as the highly ' polluted storm runoff from the streets and yards of the area. In this respect, the quality of the waters of the estuary would differ materially from that of the Potomac at the water supply intakes. In the -latter case, the waters, while muddy and sediment laden as result of rural land runoff, would not have received the large quantities of raw sewage and street filth discharged to the estuary. Thus, it is questionable whether the estuary can be considered as an acceptable source of raw water under storm conditions. However, it is also ques- tionable whether the estuary would be needed as an auxiliary source of water at such times, since there should be enough water flowing in the upper river to supply all requirements. The Sub-Task Force has made no computations regarding the period of time over which the estuary might be able to serve as an emergency water supply source, nor with respect to what effect continued recirculation would have upon quality. It has also not investigated the relationship of the estuary to needed upstream water supply impoundments. It is not contemplated in the forgoing discussion, however, that the estuary could completely take the place of upstream storage as a means of assuring an adequate supply of water for the metropolitan area. Furthermore, it is felt that a great deal more detailed study and investigation should be undertaken, before a final decision is made regarding the use of the Upper Estuary as even an emergency supply. 15. General Conclusions Regarding the UTrper Estuary. The water quality improvement measures discussion in the preceeding sections have as their objective the use of the estuary for all purposes. A review of these measures indicates that it should be possible, at reasonable cost, to bring all waste water treatment plants up to acceptable levels of waste treatment, including pro- vision of advanced treatment for the removal of phosphates. These facilities, plus some-small amount of upstream storage and the diver- sion and dispersal of some portion of the treated wastes to the lower portion of the upper estuary should make it possible to eliminate the' algal bloom problem-and make the estuary suitable for fish support and, except during times of storms, esthetically acceptable for en- vironmental and general recreational uses. Under these conditions, the estuary could probably also serve as an emergency source of water supply for the metropolitan area. Assuming that the local ------- 50 governments will, at their own expense, provide adequate secondary treatment facilities in any case, the additional costs involved are relatively modest, involving somewhere around eight to nine (8-9) cents per thousand gallons of wastes treated. Depending upon the results of continuing experiments on Rock Creek, it is also believed that, at not too great an additional cost, it might be possible to apply chemicals to quickly reduce the turbidity of the estuary following storms. Additional costs might be incurred, however, for periodic local dredging. Beyond the measures just described, the measures.required to make the estuary suitable for swimming and esthetically acceptable under all conditions, as well as to preserve and enhance its physical charac- teristics with respect to depth and surface water area, calls for additional expenditures which might amount to several billions of dollars.. Spread over 50 years, these additional capital costs would amount to somewhere around seven cents per capita per day for the residents of the entire Metropolitan area. Operating costs would add several cents more. At this point in time, it is impossible to state with any definiteness, whether at some given date in the future, or ever, it will be possible to have swimming in the Upper Estuary. Much additional investigation and research, and the construction of various demonstration and pilot facilities will be required before this question can be resolved. In any case, it will require a considerable number of years to construct facilities indicated to be needed. ------- 51 SECTION V - IMPLEMENTATION The program outlined, in the previous sections of this report calls for the contraction of numerous waste water treatment facilities as well as the undertaking of various other measures. Most of these facilities must be constructed, by the local governments and. industries involved, as part of their responsibility for eliminating water pollution. A second problem regarding maintenance of acceptable quality condi- tions in the river is concerned with the management and operation of the waste treatment facilities. The finest facilities possible are of no use if not properly operated. This suggests the need for some means of training, licensing and supervising the plant operators. It also indicates the need for continuous monitoring and surveillance of the river and of the discharges from'all outlets to the river, in- cluding a central clearing house for the reporting of spills which could be detrimental to downstream water uses and users. The objectives to be attained involve or are the concern of a number of governmental agencies, Federal, State, local and regional. No one agency is presently responsible for coordinating, supervising, managing or operating the river as a unit. Yet the river must be viewed and treated as a single: entity if these goals are to be achieved. Some form or organization is therefore required which would have_ the authority and power to undertake the various tasks required, to coordinate, supervise and assist the local governments and otherwise have general jurisdiction over the whole river. With- out such an organization, it is questionable whether-'the goals held desirable can be reached. Yet implementation is inherent in any program, if it is to have any meaning. -The Sub-Task Force accordingly recommends that every effort be made by all agencies and interests concerned to promote the establishment of an organization along the lines of that described above. ------- 52 SECTION VI - RECOMMENDATIONS REGARDING NEEDED*ADDITIONAL STUDIES 1. Need for a Reexamination of Bacterial Standards for Natural Swimming Waters. The bacterial standards' for natural swimming vaters set forth in Section II of this Report are expressed in terras of so-called "standard" coliform bacteria. These bacteria are easily identified ' organisms which are found in the bodies of all warm, blooded animals. Pathogenic organisms of human or animal origin are, on.the other hand, much harder to culture, isolate and identify. Because of this difficulty, the presence of coliform'bacteria in large numbers in water is used as an indicator of the probability that pathogenic organisms might also be present as a potential hazard to persons using the water. The standards adopted suggest, in effect,'that if the total numbers of coliforms found per 100 mililiters of the water being tested do not exceed the numbers set forth in the standard, then the hazard of contracting disease from swimming in the water is relatively, low. Unfortunately9 certain types of coliform organisms, unassociated with pathogenic types, but included in the standard definition of coliform organisms, also exist in the soil and are carried into streams with surface runoff. Also, coliforra organisms appear to have an ability to re-grow in numbers; under certain conditions, after disinfection of treated waste discharges in which they are . carried, whereas pathogenic bacteria may not. In these circum- stances 9 there might be no pathogenic organisms present, even though the colifoma count is high. To complicate this situation still further, little is known about the transmission by water of diseases common to man and beast, in situations where the disease originates in animals. Yet, as disclosed below, runoff from farms contains • large numbers of bacteria of animal and land origins. Still another complicating factor is the fact that the fate of pathogenic viruses in waste waters, whether treated or not before discharge to the stream, is not fully understood, although there is proof that the virus of infectious hepatitis survives secondary treatment and can cause epidemics. Recent limited bacterial samplings made by staff of the Interstate Commission on the Potomac River Basin at several points along the mainstem of the Potomac above Washington, and on several of its. tributaries, strongly suggest, although they do not conclusively prove, that the bacterial pollution found at most of the sampling points was largely of animal, rather than human origin. The infer- ence was based on the finding of relatively greater numbers of fecal coliforms than of fecal streptococci. These two types of bacteria, which are believed by some investigators to be better indicators of the possible presence of din ;ase organisms than are standard coli- forms, have been found in company with the standard coliforms. The significance of this finding is 'in the fact that the nearest location ------- 53 to the sampling-points of discharges of .human wastes were, in most cases, remote, and. the wastes in question in most cases received. adequate treatment and chlorination. Other samplings' on the Potomac, taken at other tines, indicate that there is a rapid and large in- crease in the number of coliforms present in the river following rain, again suggesting that these organisms are brought to the river by surface runoff and have their origin in the soil or in animals, rather than in sanitary waste discharges. From the forgoing discussion, it is apparent that the presence of •standard coliform bacteria in significant numbers in a water body is not always a reliable indicator of the probable presence of pathogenic organisms which might be dangerous to human beings, although their presence in significant numbers indicates that such a possibility exists. The question is thus raised as to the rnean- ingfullness and reliability of tests based on standard coliforms as an indicator of the probable risk involved in using the waters of the Potomac for swimming. Because of difficulties such as those just cited on the Potomac, there is widespread divergence of opinion and considerable dissatis- faction among sanitary engineers and public health officials across the Country regarding the value of the historically established bac- terial standards for swimming in free flowing streams, lakes, and tidal waters. This dissatisfaction is aggravated by the knowledge that the existing standards are not, so far as can be determined, supported by documented epiderniological studies. There is, conse- quently , a growing tendency to try to move to other standards, or other methods of control. The Public Health Activities Committee of the Sanitary Engineering Division, American Society of Civil Engineers, has devoted consider- able attention to this problem. In an extensive Progress Report published in August 19^5S the Committee stated that "health officials cannot or are unwilling to chance major relaxation of MPN standards until group judgment is squarely applied to the problem as was done by the British or until research more conclusively evaluates the question. The amount being spent to build, operate, maintain and test treatment processes intended solely for meeting MPN criteria would justify extensive research to provide a scientific and factual . basis for a national or international standard. The Committee recom- mends that ASCE point out the strong economic justification for specific controlled epidemiological research designed and executed to assess fully the health- implications of microbiological contamin- ation of recreational waters." Until more definitive standards are devised, the evaluation of the waters of the Potomac Basin for swimming and body contact sports musts of course, be based on the historical standards now in force in each of the particular States involved. This the Sub-Task Force has done. The results, as disclosed in the preceeaing sections, are generally unfavorable. Whether they would be more favorable with other standards, based on more thorough investigation, is ------- presently indeterminable. But the Sub-Task Force believes that such an investigation should be undertaken. It accordingly recommends that, in accordance with the terms of the recent memorandum of agree- ment between the Interior Department and the Department of Health, Education and Welfare regarding the availability of assistance from the Public Health Service on matters of health relating to water pollution control^ the Secretary of the Interior press for the establishment, cooperatively with the Public Health Service end other Public Health agencies and organizations 5 of a definitive investiga- tion in depth of the bacterial water pollution problem in relation to swimming, in order to establish a sound basis for meaningful bacterial and/or other standards for natural swimming waters. Because diseases of animal origin may also be involved, it is also urged that the Department of Agriculture be as.ked to participate fully in this study. The results of such an investigation would be of great value not only in planning for the use of the waters of the Potomac River, but for all of the natural waters of the Country. 2 . Need for Broadening: the Flow Regulation Provisions of the Federal Water Pollution Control Act. Section 3 (b)' of the Federal Water Pollution Control Act permits the inclusion in Federal reservoirs of storage for the regulation of flow in rivers for the purpose of water pollution control and abatement, provided that the need for such storage is demonstrated and provided that the storage is not used as a substitute for adequate treatment of the wastes at the source of the pollution. If, after the provision of such treatments there would still exist an undesirable pollution condition in the stream receiving the treated wastes, then flow regu- lation by means of releases from storage to dilute the wastes may be provided. Based on existing knowledge and general practice, "adequate treatment" has, up to the present time, been interpreted to mean secondary, or biological treatment to the degree necessary to remove at least 85 percent of.the oxygen demanding organic wastes, or equivalent treat- ment in those situations where the wastes are of a different nature. This interpretation has been applied on a uniform basis nationally. As the technology of waste treatment advances, the requirements for "adequate" treatment will no doubt be raised, with corresponding effect upon the degree of flow regulation storage required. Within any given river basin, region or hydrologic system, however, it appears only reasonable, on grounds of equity, to require that a uniform definition of "adequate" be applied. The Act also requires that the benefits resulting from the provision of flow regulation storage shall be evaluated., and provides that where the benefits are widespread, the costs of providing the storage shall be non-reimbursable; that is, shall be provided at Federal expense. ------- 55 The evaluation of benefits from flow regulation storage is not easy. • Most of the benefits are of such a nature that, while very real and' desirable, they are difficult, if not impossible to express in terms of dollars. Consequently, it has become the practice to describe the benefits in such a way as to provide a judgemental basis for determin- . ing whether or not provision of the storage appears warranted. If, on this basis, provision of the storage is deemed to be justified, then the dollar value of the benefits is, under provision of Senate Document No. 97, considered to be at least equal to the cost of providing the same benefits by the next most feasible alternative method available in the absence of the project. In most instances, this alternative has been found to be a single pur- pose dam and reservoir, usually located at the site of the proposed Federal reservoir. This is not always the case, however. In some instances, diversion of the treated wastes to the ocean or some other larger stream, may be a preferable alternative. Or advanced waste treatment may be a possible alternative. Which ever of the possible alternatives is the least costly is used as the basis for evaluating the flow regulation benefits. In some instances, the alternative used to evaluate the flow regula- tion benefits may actually be cheaper than provision of storage, even when the multiple purpose advantages of the Federal Reservoir are taken into account. Or the alternative may, for social, institutional or other reasons, be considered preferable. In such situations, the alternative itself obviously is the facility which should actually be constructed. Yet the provisions of the law as now written do not permit this because it limits direct Federal participation in the abatement of stream pollu-: tion to the provision of flow regulation storage only. No Federal agency is empowered to construct at Federal expense, or to pay for the construction of, any other alternative, even though it is more economical or is deemed to be a better solution. It would seein obvious, .however, that in the examination of the problem, all alternatives for solving it should be considered and evaluated. The Federal Water Pollution Control Administration is, of course, authorized to make grants to non-Federal governmental agencies to aid in constructing waste treatment facilities, but the grantee in such cases must also put up matching funds.; It must be recognized, however, that after financing the costs of secondary treatment, most such non-Federal agencies would obviously be unwilling to finance even a part of the cost of an advanced waste treatment or other facility as an alternative to flow regulation storage, no matter how desirable, when the Federal government will pay the whole cost of the storage. * In the case of the Potomac River, consideration of advanced treatment as a possible alternative to flow regulation storage is of much greater significance in the Upper 'Estuary than in the Flowing River portion-of the Basin. In the fluvial portion of the Basin use of advanced treatment for the removal of nutrients would as reported ------- " 56 earlier herein, apparently do little to improve the nutrient situa- tion in the Estuary and probably would do little to reduce the nutrients in the flowing river. This same type of treatment, as well as others' now under study might, however, also further reduce the residual BOD in the secondary treatment plant effluents of the Upper Basin to the point where flow regulation storage could be reduced or might even not be needed. Determination of whether such advanced treatment for removal of BOD would be more economical than flow regulation storage is, however, by no means as easy ques- tion to resolve. Water stored for control of quality in the upper reaches of the river becomes water supply for both in-stream and withdrawal uses further downstream. Storage of water for quality control is therefore inseparable from storage for water supply, as well as for flow regulation in conjunction with third stage waste treatment in the Washington area to control water quality in the estuary. To analyze these problems, a study in greater depth than was possible as part of" the Sub-Task Force assignment will.be necessary, and would probably require from six months to a year to complete. At the present state of knowledge regarding advanced treatment, however,".: it is quite probable that, because of the multiple purpose benefits derived from the stored water, flow regulation storage would prove to be the cheapest alternative for additional pollution control ". following secondary treatment for the upper Potomac Basin. In the Upper Estuary, the situation is just the reverse. Flow regu- lation without advanced treatment and.other measures would do little to correct the algal bloom problem, which is the most serious pollu- tion condition in the Estuary.' The question of who should pay for the advanced treatment therefore poses a question of equity. If flow regulation should prove to be the answer to the residual pollution load in the upper, fluvial-portion of the Basin, it can now be provided, under the laws at full Federal expense. But -the law does not permit provision at full Federal expense of the advanced waste treatment required in the estuarine portion of the Basin. Principles of equity suggest that either the Federal Government should also pay for the-advanced treatment facilities in the Washington area or that .the polluters in the Upper Basin be required to share in the costs of flow regulation storage. The forgoing discussion clearly indicates that a modification of the law is required, on both equitable and .economic grounds, in order to permit consideration on an implementing basis of all alternatives for stream quality improvement following "adequate" treatment of wastes, including advanced treatment. The Sub-Task Force accordingly recommends that studies looking toward possible modification of Section 3 (b) of the Act to provide for situations such as those in the Potomac River Basin described above be initiated. These modifications should be applicable on a National basis. In the latter context, consideration might well be given also to the inequities of those situations where ------- 57 flow regulation storage is indicated to be needed, but where no Federal reservoirs are planned or axe likely to be built. Steps toward reexardnation of this whole problem are being taken by the Department of the Interior, the Water Resources Council and the Bureau of the Budget. ------- |