At Petersburg, there is little question that the wisest approach to present and future flooding problems would be one that would seek to give reasonable protection to the development already on the flood plain but at the same time deter further construction unless it is floodproofed or houses activities that find a flood plain location so advantageous as to be well worth the risk. In currently available terms, this could be accomplished most feasibly and at the least net expenditure—though not, under present policy, as cheaply to the community itself as by the Royal Glen dam, and not without some notable changes in the town's landscape—by combining a levee system around present development with rigid zoning of the unoccupied part of the flood plain, or its acquisition as parkland.



Another approach that may shortly be possible was suggested by the President's Task Force and is the subject of legislation proposed to Congress by the Department of Housing and Urban Development. Under this legislation, owners of existing flood plain residences and small businesses would be given a chance to buy Federally subsidized insurance against flood damages at reduced rates, while new construction in flood hazard areas would be subject to rates based on the full true risk involved. After 1970, under this proposed legislation, such insurance could be sold only in areas with enforceable codes and ordinances or other measures for sound flood plain management. Such a program could go a long way toward eliminating casual and expensive flood plain clutter, if it were backed up by adjustments in other phases of Federal flood control policy that would similarly place a share of any protective costs where they belong, and hence give an additional strong nudge to citizens and local and state governments to bring the situation into balance.

At Washington, because a high proportion of the flood plain on both shores is in Federal ownership and the use it is put to is determined by Federal agencies, Executive Order 11296 has special relevance in forestalling future increases in the amount of flood damage. Existing damages in the whole urban area are estimated to average $1.4 million each year. The most damaging flood in the metropolis' history occurred in March of 1936, and if a flood of the same dimensions were to strike today, it would cause estimated damages of about $21 million.

These are not small figures, though if they are considered in the light of the area's population and extent and the total value of construction there, they seem less formidable. Obviously the threat of damages of this magnitude must be dealt with, but just as obviously as at Petersburg, the manner chosen for dealing with them should not be allowed to stimulate unwise flood plain construction that would lead to still greater longterm damages.

The Seneca reservoir as proposed in 1963 provided floodwater storage calculated to reduce metropolitan damages by 46 percent. This is a significant though not startling amount of reduction, and it constitutes the most economical one-shot measure of protection that could be attained. However, if the construction of Seneca is precluded for the time being or for good, that measure is not available. Second-best, by Army calculations, would be a combination of several large multipurpose reservoirs on main tributaries farther upstream. But quite aside from other considerations of desirability, these could only be justified economically if a great part of their stored water were destined to furnish massive flow augmentation to ease pollution in the upper estuary. As will be noted in the following chapter, recent studies have raised doubt that such augmentation would be likely to help the estuary nearly as much as had been thought and it is no longer being considered a primary tool for that purpose.

This leaves passive devices and local protection works as the main available instruments for coping with floods at the metropolis. They will probably be most effective if applied in a carefully selected combination of means, with levees and other protective works installed where feasible and desirable, and backed up in other areas by zoning, flood warning systems, and good design including flood-proofing, elevated structures, and similar devices. Some of these principles of design are already being incorporated in new buildings and renewal projects, but the task of planning and locating such things as levees usefully on a flood plain containing a good part of "monumental Washington," the beauty of which is a national concern, is not going to be simple. A good program must be instituted soon, and the extent of the Federal interest in the lands involved should considerably ease the job of coordination.

Interestingly, certain floods to which Washington is susceptible can be partially guarded against only by such approaches as the ones mentioned above, and not at all by upstream dams. One of them occurred in August of 1933, when a hurricane pushed the water in the estuary upstream and raised it to flood stage at the capital.



III THE CLEANSING OF THE WATERS

Streams have always had to carry and digest wastes that enter them through drainage from the land. It is one of their functions in the scheme of things, and so well have they performed it through the millennia that human beings have been able to take it for granted. Within limits that might be considered normal, the ability of running water to handle loads of waste is phenomenal, and in earlier times those normal limits were seldom exceeded, for even in populated areas the general lack of sanitary sewer systems kept the loads from being concentrated.

In civilized parts of the modern world, however, there are now so many people generating so many wastes of one kind and another, which often enter the streams at concentrated points, that the streams can no longer digest them without help. Too often, in the face of uncontrolled human increase and expansion, that help has either been denied them or has been weak and perfunctory. The result is plain enough now in the sorry mess of sick or dead or dying waters that we Americans have on our hands, the heritage of having kept on taking them for granted long after we had bred ourselves out of the right to do so.

As civilized rivers go, the Potomac is rather lucky. It is polluted, but many parts of it are not nearly as dirty as people are sometimes led into believing by a look at the summertime estuary at Washington. The fabled and scenic German Rhine, for instance, is much more degraded in its main flowing reaches than is the Potomac, and so are a majority of the other rivers in the northeastern United States and many elsewhere in the country. Industrialization on the Potomac and its tributaries has been spotty so far, and there are no really big clusters of population in the upper parts of the Basin. Furthermore, pollution here has already been given quite a lot of dedicated and expert attention and some rectification. Thus anyone who travels up and down the river and its tributaries finds many miles of pleasant flowing streams capable of sustaining fish and the other things that are supposed to live in and around water, and fit to soothe frayed nerves.

He will find a lot of grubby and unsoothing stretches too, extensive in places, and even in the pleasant streams troubles exist that are invisible to the eye. There is little to be complacent about, for threats are multiplying rather than fading, and some parts of the Potomac river system already need more than help; they need resurrection.



The Basin has several standard sorts of pollution, often found in one combination or another. Chemical contamination occurs along the North Branch, in areas where pesticides and other economic poisons get into the stream system, and in spots and stretches where specific industrial wastes create local problems. There is much and widespread pollution through organic wastes—often sewage solids, but not always—whose breakdown by natural processes may demand so much oxygen that a stream has little or none left over to maintain aquatic life and "stay alive."

Sometimes associated with organic wastes and sometimes entering the river system otherwise are dangerous bacteria, and also the so-called "nutrients"—dissolved fertilizing agents that can stimulate excessive growth of algae or weeds in the water to the detriment of other forms of life, often to such a degree that these plants' death and decay sets off a whole new cycle of oxygen demand. And there is sediment washed off the land, which clouds the water and settles out into a smothering cloak on the bottom, building up in quiet stretches into ugly and damaging mud banks and shoals.

Troubles above the Fall Line

Pollution of the Potomac begins at or near its traditional source, the tiny Appalachian spring at the head of the North Branch where in 1746 Thomas Lord Fairfax's surveyors set an inscribed stone to mark the northwestern corner of that possessive nobleman's vast holdings. Abandoned strip coal mines lie within sight of the spot, and it is doubtful that the infant river trickles more than a few yards before receiving its first injection of the acidic mixture of substances that springs and seeps and runoff water extract from bared coal strata and the mines' spoil heaps and carry down to the streamlet they feed.



Such additions are frequent for the next 45 miles or so downstream, as the North Branch in its narrow valley swells into a mountain river with the water of brooks and creeks flowing off ridges pocked with coal mines old and new. The river and such tributaries sustain no aquatic life at all among the discolored stones in their channels.

This mine-derived pollution has been much studied but is still not well understood. Sulphuric acid is its most damaging component, but may be accompanied by iron salts and other substances also leached from materials in and around the vast coal beds of Appalachia. Some acid entered the streams there naturally, before men ever touched the coal, but it has increased to deadly proportions with widespread mining. It issues from both surface strip mines and the old-fashioned underground sort, though the latter furnish by far the most—an estimated 75 to 90 percent. The overall magnitude of the problem is indicated by the fact that the more than 60,000 square miles of the Appalachian region underlain by coal, including the Potomac fraction, contributes five to ten million tons of sulphuric acid annually to streams and rivers, a rate of production that is expected to continue for at least a thousand years.

At Westernport the North Branch enters more populated realms, and receives one of its latter big doses of acid from Georges Creek, which drains a devastated, economically depressed valley mined since very early days. This creek may be the single most unfortunate stream in the Potomac Basin, for the accumulation of raw wastes it brings down from the valley's communities is pickled rather than assimilated by its heavily acid water.



In the 40 or 50 miles below that point, the North Branch accumulates great quantities of more usual kinds of pollution as it runs down a broadening valley past towns and industries that have grown up because of the conjunction of coal, timber, water, and railways—and in the old days water transport, for flatboats used to shoot the river at high water, and later the C. & O. Canal operated upriver as far as Cumberland. Treatment of wastes in this reach is spotty and mainly inadequate. Some industries and towns sluice them raw into the dark, sad water, and others give only perfunctory primary treatment; the city of Cumberland releases the equivalent of about 18,000 persons' body wastes each day as effluent, besides extra raw wastes whenever storm runoff overloads its combined storm and sanitary sewer system and causes it to overflow. Where major efforts have been made, as at the Upper Potomac River Commission's Westernport plant below the big Luke, Maryland, pulp and paper mill, the wastes are so voluminous and complex that some of them still have to be dumped, and the effluent from even highly efficient treatment further degrades the river.

Fortunately, the North Branch, acid above, deprived of oxygen and overenriched and septic below, is not typical of the flowing parts of the Potomac river system, but it stands as a good grim example of what pollution can mean, and as a foretaste of what may be expected to happen elsewhere in the Basin if it is not stopped soon. Mine acid is not a significant problem in any streams outside of that region, but untreated or inadequately treated wastes are badly blighting many streams and rivers or stretches of them. Some smaller watercourses, like historic Antietam Creek below Hagerstown, Maryland, have deteriorated under the influence of discharges from single or limited sources, while larger ones suffer from a cumulative waste buildup in areas of concentrated population or industry. Some twenty miles of both industrial and municipal pollution in the South River Branch of the Shenandoah's South Fork below Waynesboro, Virginia, have done much damage to that legended river for a good distance downstream, a situation that is worsening with the area's growth. On the North Fork of the Shenandoah similar effects have been wrought by heavy organic loads from poultry processing and other things. The list could be extended: aside from a few happy exceptions like the prized Cacapon, draining rugged, forested, thinly peopled hill country, nearly all the Basin's flowing streams of any size receive damaging loads of waste from towns and industries.

[Illustration: WATER TREATMENT STEPS

(1) River water enters here

(2) Water chlorinated

(3) Water settles. Heavy particles sink

(4) Water pumped to Pretreatment Building

(5) Various chemicals (chlorine, alum, lime, carbon) added. Chemicals and water stirred in rapid mixing basins

(6) Slow mixing to form "floc" (see Alum below)

(7) Water settles for 2-1/2 hours. "Floc" carries impurities to bottom

(8) Water filtered through 94 rapid sand beds

(9) Final chemical treatment (chlorine, lime, fluoride, phosphate)

PURPOSE OF CHEMICALS

CHLORINE: Destroys organic materials PHOSPHATE: Lessens pipe corrosion FLUORIDE: Lessens tooth decay CARBON: Controls taste and odor ALUM: Forms "floc" (snowflakes) to trap impurities LIME: Helps "floc" formation; lessens pipe corrosion ]

The basic and usual damage comes from oxygen depletion. A stream has a natural capacity for hastening the decay of organic wastes, which is determined by such things as the volume of its flow, the pollution already in it, its velocity and depth, and its temperature. When that capacity is exceeded, as we have noted, too much of the stream's oxygen is used up by the process of decay and the stream, which is an intricately complex work of living things, begins to die. Under really bad conditions, the waste solids themselves cannot all be assimilated, and hence may build up in layers of stinking sludge at the bottom of the stream and continue to seize available oxygen for a long time thereafter.

Conventional waste treatment, in plants built by towns or by industries whose raw materials are animal or vegetable in origin, is aimed at removing the solids in the wastes and reducing the bio-chemical oxygen demand—called B.O.D. It is a speeded-up version of the same process of purification that goes on normally in any stream when loads are not too heavy. "Primary" treatment removes such solids as will readily settle out and passes the rest on back to the stream as part of the effluent. "Secondary" treatment plants, after settling out the gross solids, speed up decay by furnishing air to the bacteria that eat up dissolved and finely suspended materials; a good secondary plant, under much more skillful supervision than is usual, can get rid of 85 or 90 percent of the organic materials and the associated B.O.D. by the time it turns its effluent into a stream. How damaging that effluent will be depends on a number of things, chief among them being the size and condition of the receiving stream and the volume of organic materials that went into the treatment plant in the first place. A riverside town of 1000 with a secondary treatment plant operating at 75 percent efficiency is going to inflict on its river a daily load roughly equivalent to the raw sewage from 250 people.

Over the years a lot of hard effort, notably on the part of the Interstate Commission on the Potomac River Basin, has resulted in some degree of treatment for about 85 percent of all municipal wastes and 83 percent of those produced by industry along the Basin's flowing streams. Put in another way, by INCOPOT calculations the total waste load imposed on the Potomac is only about three-quarters of what it was in 1956, despite a population increase of nearly a fifth.

That it is still much too high in many parts of the upper Basin does not require elaborate instruments to detect, but only a nose and a pair of eyes. A very few industries and towns are still dumping raw wastes, and many of the others need better and bigger sewers and treatment plants or better operation of the plants they have. Sewage collection systems are sometimes of the old-fashioned combined type, like Cumberland's—and, as we shall see, like Washington's—which have to carry storm runoff as well as wastes, and overflow during rainy periods, releasing heavy pollution without treatment. But even separate sanitary sewers are often overloaded by having to serve greater populations than they were designed for, which means that their escape valves may leak raw sewage more or less continuously into surface watercourses and that the quality of treatment given the sewage that does reach the treatment plant signifies less than it ought to.

Antiquated or overloaded treatment plants cause much trouble. Old primary plants too small for present populations often remove only about a third or less of the organic material, but by their very existence they tend to lull communities into a false conviction that they are doing their part toward clean rivers. Tiny plants of the sort authorized locally for new leapfrog subdivisions and vacation colonies are usually doomed to restricted efficiency by their very size. These often are underdesigned even for initial loads, let alone for the growth that comes later, and most of them are poorly run.

This question of operation is crucial. A new, well-designed, expensive plant in slovenly or inexpert hands—a frequent paradox—can put out a much greater waste load than a well-operated old one. The plant at Romney, West Virginia, on the lower South Branch, the best example of responsible operation in the Basin, is old, but because it is well run it usually achieves about 92 percent elimination of B.O.D. in comparison with the 75 percent or even less that some newer and more imposing plants can claim.

The reasons for poor operation are various. One is a shortage of qualified operators, based on a need for better salaries, more training programs, and rigid mandatory State certification of operators' abilities. Another reason can be a pinchpenny attitude on the part of municipal authorities toward sewage treatment. It is one sizable expenditure whose results cannot easily be pointed out with pride to local taxpayers at election time, for its main effect is usually downstream from the municipality itself. Thus the big encompassing reason for bad plant operation—cutting corners, refusing to spend what needs to be spent, failing to supervise—has to be called philosophical. It comes from a failure on the part of local operators and authorities and much of the public to comprehend the immorality of deliberate avoidable pollution, and it may mean that municipal operation of treatment plants is itself often a major source of trouble.

A clear example of this philosophical deficiency is one large Basin treatment plant that was reported to have "handled"—i.e., properly disposed of—a third less sewage sludge in 1965 than it had in 1960, despite a large increase in the population it serves. The unhandled sludge, of course, went straight into the local river for reasons of convenience, economy, and callous indifference.

For the most part, large private industry demonstrates more responsibility in this respect than the Basin's municipalities or Federal installations. There are some miserable exceptions where individual industries dominate a locality's economy and take casual advantage of that fact. But responsible industry is concerned with public relations, and knows that a fish kill or a gray-blue stretch of blighted water downstream from its outfalls is the poorest kind of public relations to be had.

To be able to say precisely how much bad plant operation is adding to pollution in the Potomac will require exhaustive and continuous sampling and analysis of a kind that may be expected now that the Water Quality Act of 1965 is about to make itself felt through application of new State water quality standards. But experienced observers in INCOPOT and elsewhere feel strongly that bad operation does much more damage than do over-aged or outgrown facilities, though these play a big part too.

Bacterial pollution—the category of most interest from a public health standpoint—fluctuates a great deal in the Basin's flowing streams, but is heavy in most of them by current standards during times of normal flow. It may come from raw waste discharges, from treatment plants that skimp on chlorination of their effluent, or from storm runoff and natural drainage off the land and urban pavements. But before anyone can confidently say how dangerous it is to swimmers and others who make intimate use of rivers and creeks, water scientists are going to have to learn more about its measurement and classification than they presently know.



No easily applied method of testing can effectively establish the guaranteed absence of human disease germs. The traditional "Coliform Count" plays safe, as it must. It measures the concentration of certain easily spotted "indicator" organisms that do not themselves make people sick but are always voluminously present in the fecal discharges that can carry harmful germs, and it gauges the danger by the concentration of these indicators.

However, concentrations of coliform bacteria, originating in animal manure or elsewhere, may invade a stream through runoff from rural lands without having any meaningful relationship to human disease germs. Counting them under such circumstances is a little like measuring the depth of the proverbial well by the length of the pump handle. Furthermore, no one really knows how easy or how hard it may be to catch given diseases by swimming. In this country, outbreaks of leptospirosis, an illness common to man and certain animals, have been traced to swimming holes, and other links are obvious. On the other hand, some careful British investigations turned up a good many quite healthy people who habitually splashed about in sea water teeming with pathogenic organisms of one sort or another. Sea water and fresh water have vastly different qualities, but the subject is presently full of confusion, and it needs much research.

Land runoff in general furnishes a large amount of pollution of all classes, and in all parts of the upper Basin except the least-used forest sections. Besides bacteria, heavy loads of organic material may be washed into streams in regions with high densities of livestock or poultry, and some pollution of this sort is found practically everywhere. The wild and domestic animal population of the Basin above Washington has been estimated to produce wastes equivalent to those of about 3.5 million people. Much of this is dealt with by the "living filter" of the soil, but much also reaches the streams, associated with sediment from erosion producing rains. And the sources, particularly in areas such as those along the Shenandoah and the Monocacy and other streams with wide rich valleys, are numerous and diffuse.

Nitrogen and phosphorus nutrients, which foster weeds and slime in quiet stream stretches and contribute to the problems of the estuary downstream, are found in undesirable concentrations in most of the Basin's waters above the Fall Line. Not only are the growths encouraged by these fertilizing agents ugly, but they also upset the ecological balance of streams by favoring certain types of aquatic life over others, and they can cause tastes, odors, and clogging in water supply systems and sometimes, by rotting, a secondary sort of oxygen deficiency. Nitrogen and phosphorus occur in the effluent from waste treatment plants, for they are present in human wastes and in detergents, and in dissolved form are little affected by standard treatment processes. And in the upper Basin a large part of the nutrient load in streams appears to be associated with sediment from the same diffused land runoff mentioned above, for they occur abundantly in manure, in synthetic fertilizers, in certain natural soils, and in decaying organic substances of many kinds. The health and growth of living things is dependent on these elements, of course; it is their excessive release into waters that causes trouble.

From the same farming regions and even more from lawns and gardens and parks in more populated areas, pesticides and other economic poisons accompany sediment into the stream system or are blown into it as sprays and dusts. They seem not to be as great a problem in the Potomac as in some other rivers, but they are present in probably significant amounts; indicator tests hover near Public Health Service drinking-water limits in the river. Their use, here as elsewhere, increases year by year, for they are tremendously effective against many of man's ancient enemies. Being easily available, they are often used in uninformed and careless ways despite government efforts to determine and publicize safe levels of application. Knowledge about their side effects, both immediate and long-term, is still full of gaps. Badly misused, they are obviously dangerous. But information about the precise results of their ordinary use and their buildup in nature accumulates very slowly.

The persistent chlorinated hydrocarbons—DDT and its relatives—last for a long time after being released into the environment, concentrating at various points in the natural food chain and often in man himself. It is said that an average adult Californian's tissues today contain more DDT than is allowed in beef for interstate shipment. But no one is yet certain what this means in relation to that average Californian's physical wellbeing, and in terms of fish and wildlife, though the link between these materials and certain destructive changes can be seen, evidence in other cases—the declining fertility and numbers of bald eagles, for instance, which some investigators believe to derive from pesticide residues—only points toward such a link. Until all the facts are in and the impact of such poisons has been clearly restricted to the pest species at which they are aimed, they are going to continue to be a heavy concern for conservationists and others alarmed about environmental pollution, along the Potomac and elsewhere.



One of the principal Potomac pollutants, silt, not only comes from the land but is the land, most often good topsoil, washing away toward the sea. Even under pristine conditions streams are likely to run somewhat muddy after storms; it is a natural phenomenon, a by-effect of the way climate carves landscapes. On the evidence, however, the Potomac landscape since its colonization by white men has been undergoing a much more rapid carving than anyone could consider to be natural. Most of its streams, particularly in their lower reaches, are thickly opaque for long periods after rain, and gross erosion in the Basin—the amount of soil washed away from where it usefully belongs to somewhere else—averages about 50 million tons per year, a major depletion of the soil resource and a degrading influence on the landscape through erosion. The part of this silt that gets into streams cuts down on the usefulness of the water, creates ugly turbidity, chokes quiet pools and reservoirs, suffocates bottom-dwelling creatures and plants on which the streams' wholeness may depend, and rides down the current to add heavily to the problems of the estuary, into which some 2.5 million tons of it are annually discharged.

Sediment is dislodged from the land by the pounding action of raindrops and the flow of runoff, and sometimes is washed from streambanks during high flows—which may themselves be higher and more frequent because of silt-clogged channels. The bulk of it can be blamed on unsound land use. This may be rural, based in the old use-her-up-and-move-along pioneer outlook that has never died out among us despite wide understanding of better ways of doing things. People in places still overgraze pastures and clean-cut timber so that rain can get at the soil and eat it away, and they still farm land too steep to stay in place without its vegetative cover, or they plow even suitable rolling land in straight rows up and down hill so that water and soil sluice away together down the furrows when it rains. Despite a sharply effective three decades of work and public education by the Soil Conservation Service and other agencies, these old practices continue in some places and cause much erosion.



Also, increasingly, bad land use involves the ways in which great machines adapt the landscape to hundreds of sophisticated purposes. The massive eatings of powered blades and scoops to get at coal and other minerals on the steep slopes of the North Branch watershed and elsewhere, add heavily to sedimentation. So do broad rights-of-way gashed out of the countryside and left bare under storms in the months before highway construction is done, and secondary roads that even when finished may be left for years or forever with denuded clay shoulders and ditches and banks that wash with every rain. And so, most particularly, do the great polygons of rolling land around the Basin's town and cities that are stripped naked by bulldozers and left sitting in that condition for long periods, while they await the erection of buildings and blocks of homes. This is occurring throughout the Basin, but most notably around Washington, where the highest erosion rates of all are found. We will take a look at its details and the reasons for it a little further along in this chapter when we examine the estuary's situation.

Except for the acid parts of the North Branch, the upper Basin's waters in most places, most of the time, can still serve the "practical" purposes to which they are put—irrigation, industrial uses, municipal supply after purification, and even the absorption and digestion of effluents from adequate, well-run treatment plants. Most of the streams are usually good to look at, especially in conjunction with the superb rural landscapes against backgrounds of wooded mountains that are characteristic. They furnish much pleasure to fishermen, hunters, boatmen, swimmers, picnickers, and other folk, though in some places it is an open question, as we have seen, whether or not contact with the water is prudent. And almost everywhere, aging locals can recall a time when their stream was a happier amenity than now—when it held more fish, ran clearer over stones and gravel not coated with weeds and green slime, did not have the smell it presently emanates, was colder and more copious....

Their nostalgia probably does not play them false, even though conditions in many places are better now than in the intermediate past, after modern times had settled in, but before INCOPOT and the Soil Conservation Service and such influences had begun to push for reform of the casual, anciently human ways of doing things in which present human populations can no longer afford to indulge themselves. Some of the gains that have been made are being cancelled out by growth and new types of pollution, however, and in general the flowing Potomac river system is teetering at the brink of bad trouble. It needs help.

If the flowing upper Potomac had any lingering oxygen deficiency in its lower stretches—though it seems usually not to—it would tend to rectify the lack in its turbulent eighteen-miles descent across the Fall Line, a superb natural "treatment plant." Normally it arrives at Washington charged with oxygen, but does bring down with it the part of its nutrient load that has not fertilized upstream weeds and algae, periodic waves of bacterial concentration, and a great deal of debris and silt in season.

In the broadening, slowing upper estuary, its sluggish currents confused by the twice-daily surge and ebb of tides, these materials from above are stirred in with an array of specifically metropolitan pollutants—with more silt off of the outraged urban watershed, with junk and debris of a thousand sorts, with decaying substances and bacteria from many sources, and with vast new quantities of nitrogen and phosphorus. The consequence is a weighty and sometimes spectacular pollution problem directly adjacent to the proud national capital. It is at its vivid and aromatic worst in summer, when the most Americans come there fondly to view the city and the Potomac, and when locals who want to boat and fish and swim and do the other things one does on water would make most use of the river—indeed, do make use of it in spite of everything.

Like the meek, the upper estuary inherits the earth, or at least that part of the Basin's earth that is washed downriver as silt. There are enough fine suspended sediment particles in the water of the metropolitan river to make it drably opaque most of the time, even during relatively dry spells, when heavy sand and gravel dredging helps to keep it stirred up. As the current loses force and washes back and forth with the tides, the particles settle out slowly into smothering, continually renewed blankets on the bottom, and over two centuries have accreted into great mudbanks and shoals. Channel dredging to maintain navigation has been going on since the early 19th century, about 180,000 cubic yards being presently removed each year. The dumping of the dredged materials on the marshes and long low shores has built up wide, flat, new flood plain areas around the city over the years, including the sites of Washington National Airport, Anacostia and Bolling Air Fields, and East and West Potomac Parks.

Such channel dredging has little effect on the gradual shoaling of this whole part of the river in general. Miles of formerly navigable water downstream from Memorial Bridge are now only one to four feet deep and useless for either pleasure or commercial craft. It has been estimated that present rates of deposition will within fifty years fill in the upper estuary completely to a mile or so below Alexandria, except for a river channel. The same process is at work in the tributary creek-bays that give onto the estuary, some of which have silted so heavily since Colonial Days that formerly thriving ports—among them Bladensburg, Dumfries, and Port Tobacco—are now distant from the water.

The bulk of estuarial silt comes down the main river from the upper Basin. But a heavy increment is added in the metropolitan area. Modern mechanized development of the city's hilly environs on a huge scale, continuing year by year with few thoughtful rules to guide it heretofore, has brought about erosion that on individual patches of bared land may reach a temporary rate of 50,000 tons per square mile per year, and even average rates in this area are far in excess of anything else in the Basin.

We had to examine the reasons for this rather closely last year in a study of Rock Creek's ailments, whose findings we published in a report called The Creek and the City. This much-admired metropolitan stream has been relatively well protected, with the parks along its wooded valley and an upper watershed that until quite recently remained essentially rural. But as development has proceeded in standard and careless ways—the wholesale stripping and scarification of big tracts of rolling, fine-textured land, the long naked wait for development—the creek has come to be muddy and ugly almost all the time and has been spewing an estimated 100,000 tons of sediment a year into the estuary, with frequent floods.



To help save the creek and its parks and to stimulate a better kind of development of the rest of its basin, citizens formed a watershed association under Soil Conservation Service auspices and brought about the construction of two small upstream reservoirs to control flooding—with results noted in the preceding chapter—and to collect silt. They sought to promote better land use as well, for the reservoirs' effectiveness is obviously dependent on their not filling up quickly with an excess of sediment. Better land use around a city depends on zoning and other legal devices to regulate the density and distribution of construction, and on controls over the way land is shaped, and a sharp conflict developed between the watershed's defenders and the Council of Montgomery County, Maryland, in office at that time, whose rezonings in favor of standard massive suburbanization and whose failure to enact sediment-control ordinances threatened the whole effort. Rock Creek has many friends, and their subsequent fight for its salvation has had good effect, though much remains to be done.



However, Rock Creek is only one of many metropolitan streams that need protection, both for their own sake and for that of the estuary. Some are getting it—in the preceding chapter we noted the happy example of Pohick Creek in Virginia, where whole watershed planning is being accomplished almost from scratch, before development. But many more are being ruined by the steady advance of standard urban sprawl.

Thus the main cause of urban silt is faulty or nonexistent or powerless land planning, and the problem merges with the whole question of landscape preservation. The ecological principles involved in good practical land planning—the distribution of uses based on what land and water can take without being degraded and causing silt, flooding, and downstream pollution—are the same basic principles that lead to scenic beauty and a decent human environment. This is a subject we will explore in more detail when we arrive at considering the landscape as a whole, but for now it may be worthwhile to note that insofar as urban erosion and silt stem from decisions of political agencies inclined to subjugate well-known good land use principles to speculative pressures, expediency, and other things, their origin is political and economic.

Organic materials are pervasive enough in the upper estuary that during periods of even normal flow their decay pulls oxygen levels down. Under usual conditions this B.O.D. grows worse and worse downstream and reaches a peak in the neighborhood of Mount Vernon, though its effects continue to be felt below. Fish kills among the rugged resident species that predominate in these reaches of the river are not uncommon, the shoreline windrows of deceased carp and perch periodically adding their essence to what metropolitans have come to accept as the Potomac's normal summer smell. And along with the organic materials are heavy concentrations of bacteria.

The organic and bacterial load enters the estuary from many sources, most of them local, for only a little of this material comes down from the upper river. A significant amount of it issues from the network of small urban watercourses like Rock Creek. Many of these were covered over as storm sewers or troughed in concrete long ago, but they continue to serve their age-old function of draining the lands they traverse, even if through cast-iron gratings.

A good bit of the organic load in these tributaries consists of raw human waste, incongruous and particularly obnoxious around a modern city. The bulk of it is released in periodic surges when local rainstorms overload the old-fashioned combined sewer systems of the District of Columbia and Alexandria. In dry weather these systems send both collected sanitary wastes and street drainage down to the cities' respective treatment plants, but during storms when street drainage is heavy the sewers' capacity is exceeded and overflow gates gush mixed stormwater and sewage out into the streams, which carry it to the estuary.

In the suburbs, more modern separate storm and sanitary sewers are the rule, but they too have some problems of a kind we noted in relation to the upper river. Investigations on Rock Creek revealed steady dribbles of raw sewage entering the creek or its tributaries from a large number of storm-sewer outfalls and other places. Partly these flow from malfunctioning individual septic systems in outlying areas, surreptitious connections of house sanitary sewers to the storm system, breaks and leaks in sanitary sewers, and such things. Partly too they seem to come from the fact that some sanitary sewers are having to carry more sewage than they were designed to handle, so that their overflow valves leak more or less constantly into the storm sewer system. The capacity of sewage collection systems is related to planning. If a pipe is laid down to a fringe area where county zoning maps indicate only limited development is going to be permitted, its size is gauged to that kind of development. But if the zoning is changed later and three times as many houses are hooked up to the line as were originally envisioned, trouble results. Rock Creek is heavily affected by such sewage, and the chances are that the situation is much worse on many other urban drainways, for their longstanding degradation or sheer disappearance from view has lost them the alert defenders who watch over Rock Creek in its pleasant valley.

Out of the storm sewers whether combined or separate, off of the roads and streambanks and hillsides, down the urban tributaries or directly overland into the estuary, comes still another big jolt of organic and bacterial pollution every time there is a heavy rain. This is surface runoff, the washings of the street and parks and sidewalks and rooftops. Besides debris, it contains vast hordes of bacteria and many kinds of organic oxygen-demanding substances, of which animal droppings are only one easily definable example. Around a city the size of the Washington metropolis, this runoff would constitute a worrisome pollution problem even if the matter of sanitary wastes were thoroughly in control.



Ships and large boats in the estuary, in accordance with an unfortunately persistent nautical tradition, generally discharge toilet wastes and garbage directly into the water on which they float. Some of these are coastal or transoceanic vessels, both commercial and naval. Many more belong to the fleet of pleasure boats which have been increasing at Washington despite the water's unpleasant state to which they add their bit, degrading the element that is supposed to provide the enjoyment for which the boats were built. It is not a problem limited to the Potomac estuary, but widespread these days and the focus of much concern among public health and pollution control authorities, conservationists, and the boat and marina industries themselves.

Around the various marinas to be found along metropolitan shores—several of them Federally owned—sanitary facilities are generally skimpy, and no regulations govern the discharge of wastes from boats. Since individual marinas may berth as many as 600 or 700 craft, a great many of them in daily use during the recreation season and some inhabited as dwellings the year round, summer conditions that frequently prevail around these places are not to be described in polite terms.

Less visible at the point of origin though not in its ultimate effects is the huge organic load that comes to the estuary in the effluent of local sewage treatment plants, estimated at possibly 300 to 350 million gallons per day. There are many smaller plants strung out down both shores of the upper estuary, but four larger ones handle the bulk of metropolitan sewage. Of these, three—the main plant at Blue Plains in the District, the Alexandria plant, and the Fairfax County Westgate plant—furnish secondary treatment, and the fourth, the Arlington County plant on Four Mile Run, is on the verge of putting new secondary facilities into operation.

Yet the same problem of plant operation that exists in the upper Basin also rears its head here. A casual boat ride down the shoreline with a few excursions up tributary creek-mouths demonstrates that many of the smaller plants, including a number of Federal ones, are emitting a very low quality of effluent, and this is borne out by sanitary surveys. The proliferation of such small plants around cities and elsewhere is a headache to sanitary authorities, for their very size and numbers create a probability of trouble. Much effort is going into eliminating them and channeling the wastes they receive into the larger plants.

But the large plants themselves at this point are a much bigger part of the problem; on the basis of sheer volume, their contribution to estuarial pollution dwarfs all others. The Blue Plains plant is by far the largest of the four, handling wastes from about 1.4 million people in Washington and outlying areas on both sides of the river. By the terms of a conference convened in 1957 by the Public Health Service to investigate the sanitary state of the Potomac at Washington, the District committed itself to maintain 80% efficiency of treatment at this plant, which was then brand new. Last year, ten years afterward, the most generous recent calculation of the efficiency there was 62%, and some qualified observers expressed a conviction that Blue Plains had never consistently functioned at much over 50%—in other words, it had been returning to the estuary unassimilated organic materials equivalent to the raw discharges of a population of roughly 500,000 to 700,000 people each day. Nor do these figures include a great deal of sludge that has been flushed on into the river when digesters have failed to function properly, or the plant's frequently inadequate use of chlorination against bacterial pollution and odors. Since the same 1957 conference required of the other metropolitan jurisdictions only that they do equally as well as the main plant in quality of treatment, they have clearly not been obligated to superhuman effort.



Criticism of Blue Plains is in part criticism of ourselves. Because of the distinctive relationship between the District and the Federal Government, the District's treatment plant is in a sense a Federal installation, funded through Congress and with more direct links to Federal water quality agencies than any other big municipal plant in the country. The number of people the plant serves has, of course, increased greatly in the past ten years. It may have been, as has been claimed, somewhat underdesigned to begin with, and it undoubtedly needs expansion now. Yet a rather substantial improvement in the quality of treatment there in quite recent months, mainly under the stimulus of this planning effort and the present surge of interest in the Potomac, indicates that had emphasis on low operating costs been subjugated to pride in results, the present plant could long ago have been made to function reasonably well and the estuary would have had to cope with a much lighter load of wastes.

The truly spectacular manifestation of pollution in the metropolitan Potomac is the periodic growth of algae there in summertime. When conditions are right—when sun, summer temperatures, low inflows from the river above, and a heavy concentration of nitrate and phosphate nutrients all combine to make of the upper estuary one vast inspired pool of fertility—the whole surface of the river may be covered with a thick bright emerald mat, and boats that pass at speed leave wakes of green instead of white. The infestation may extend downstream for thirty or forty miles, in various degrees of concentration, and even if the water were bacterially safe this "bloom," as it is called, would prohibit its recreational use by anyone without a strong stomach. It further disrupts aquatic life balances, and periodically dies and decays aromatically, setting off whole new cycles of oxygen depletion, fish kills, stink, and fertilization.

The problem is one of fertility, of course, and stems from the huge quantities of nitrogen and phosphorus perennially present in the water. Some of this comes down from the upper river—where, as we noted, much of it derives from land runoff—but by far the greatest part of it originates at the metropolis and enters the river through the effluent of waste treatment plants. Efficiency of operation has hardly anything to do with it, for even the best standard treatment has little effect on nutrients.

Eutrophication is the scientific name of this kind of overenrichment. It is occurring in many places, Lake Erie being the best-known single example in this country. Though its causes are mainly known, the process itself is still not fully understood, particularly in regard to the function of nitrogen and the way it works. But the other key element, phosphorus, has been more amenable to study and to possible action. It occurs in body wastes, in artificial fertilizers, as a by-product of natural decay, and very notably in detergents. Some eight tons of it are released into the estuary each day from the treatment plants in addition to the undetermined but much smaller amounts arriving from upriver, and the usual overall accumulation is enough to make the river's phosphorus content exceed that considered desirable all the way from Theodore Roosevelt Island to Quantico, Virginia, and below, which represents the general extent of the summertime "blooms."

Dilapidation begets disrespect, and the abused and often repellent waters of the upper estuary are undoubtedly subjected to much additional miscellaneous pollution by people who believe perhaps that a little more cannot possibly matter. Again, Federal or Federally connected institutions have not been setting the best possible example, and there are many of them around the capital city. Unwarranted waste discharges of one kind or another have been traced to most of the military installations fronting the river, to military hospitals, to government heating plants, to the National Zoo, to National Parks, and to similar Federal sources including the marinas already mentioned. In most cases, measures are now being taken to eliminate these discharges, but it is a commentary on the complexity and difficulty of the whole task of dealing with pollution that at the level of government where real concern with the problem has been acute for a decade or more, and furthermore at and around the very seat of that government, such practices should have persisted this long.



Junk and debris of all descriptions infest the metropolitan river, floating about, washing onto the shores, poking up stolidly here and there out of mudflats. Most items in a dreary inventory that might be compiled would turn out to be something that was discarded somewhere it didn't belong by someone who did not want to go to the trouble to put it where it did belong. Therefore, the main source is undoubtedly simple disregard for the sensibilities and rights of others, multiplied and complicated by the immense number of people in the metropolis and the wide territory they occupy. In our study of Rock Creek last year, some powerful subsidiary reasons for the prevalence of debris turned up also, ranging to streetcleaning methods and the inconvenient hours kept by some public dumps where citizens have to carry their larger trash. Metropolitan problems are seldom simple, and many of them in one way or another manage to inflict a part of their complexity on the river at the national capital, which is sad but possibly appropriate in a time like the present.

The lower estuary

Downriver from the main effects of the metropolitan complexities, the widening brackish and salt portions of the Potomac estuary form a generally healthy body of water, though changes loom as the metropolis moves inexorably outward from its center and as hitherto remote Tidewater areas are brought more and more under the influence of modern ways of being. Localized problems of pollution point to general dangers that will certainly materialize unless safeguards are set up in time, for estuaries are delicate, immensely productive, and still somewhat mysterious aquatic environments that have been and still are too much taken for granted.



Rapid human intrusion on estuaries during the past twenty years has been making apparent their phenomenal value in a natural condition. Vulnerable, attractive to diverse interests that work their beds for sand and gravel and fill in their marshes for development and casually pollute them, they have recently been called America's most endangered natural habitat. They are almost unbelievably fertile places, with involved biological cycles that can convert the fertility into usable food at rates per acre far exceeding those of the finest farm land; in terms of money, one recent set of experiments indicates the possibility of attaining an annual shellfish production on tended beds worth over $26,000 an acre.

Furthermore, aside from the direct harvest of this wealth from estuaries each year by commercial and sport fishermen, these in-between waters make an indispensable contribution to the entire Atlantic coastal fishery, an industry worth a billion dollars a year. The reason for this is that at least 70 percent of coastal fishes spend some essential part of their life cycle within an estuary—spawning there, or passing through on their way to spawn in running fresh streams, or moving in as fry from the rivers or the open sea to find a "nursery" in one of the varied estuarine habitats—bays, marshes, sandy shorelines, mudflats, tidal creeks, or weed beds.

The oysters from the famous beds in the Saint Mary's River off of the lower Potomac are mainly condemned as unfit for consumption because of local sewage pollution, and these beds are not the only unfit ones, for towns and resorts in the region have been growing and sanitary facilities have not been keeping pace. Already some arms of the superb natural harbors formed by the tributary creeks are noxious with discharges from boats at big marinas, and gravel dredging is stirring up silt to smother bottom life, including shellfish. As Tidewater agriculture revives and modernizes, pesticides and artificial fertilizers are coming to be as much a part of the scene there as in other farming regions, and may be expected to influence the estuary—in fact, they undoubtedly already are doing so in subtle ways with effects not yet apparent.

Yet most of this part of the river is still beautiful and continues to yield good harvests of seafood. The Potomac River Fisheries Commission has been alert to obvious dangers and has moved against them where its powers have permitted, and natives of the area are increasingly alert in protecting the estuary. Many of them depend on it for a living, most are oriented toward it for their pleasures, and until lately a good many of them counted on it for transportation. In a number of different ways, it matters in their lives. And that fact offers some hope for the future, especially if it is fostered and strengthened by overall protective measures.

Techniques for cleaning up

Two main general approaches to water quality improvement exist: treatment of pollution at its source or occasionally after it has entered a stream, and augmentation of the stream's flow to help it assimilate loads of waste beyond its natural capacity. A third possibility in certain situations is the diversion of wastes out of a stream's drainage entirely. In practice, these methods can be varied and combined in any number of ways to fit a need.

To take the last one first, diversion of whole wastes as received from their sources is a total and dramatic means of coping with a pollution problem stemming from collectable wastes, but it often has disadvantages. One of these, of course, is the possibility that the pollution problem may be simply transplanted elsewhere—that the water in which the wastes eventually end up will suffer. Another is loss of water from the stream system. If, as is usual, a town gets its water out of the local river or a tributary and does not give it back after use—preferably well cleaned up—other users downstream are not going to have as much water available to them, and the essential processes and ecology of the river itself may suffer.

The only place such wholesale diversion of wastes has been seriously considered in the Potomac Basin is at metropolitan Washington, whose sewage could feasibly be piped across Chesapeake Bay and the Delmarva peninsula and well out into the Atlantic—possibly, as has been suggested, in combination with sewage from Baltimore. It would be a permanent means of disposal, but very expensive in terms of both investment and operating costs. Furthermore, though in the estuary no downstream users would suffer a loss of water supply, the water content in metropolitan sewage has at times risen as high as 80 percent of the flow of the river above the upstream intakes. The effects of such a subtraction of fresh water on the estuary itself—changes in flow, and in the penetration of salt water upriver, with an inevitable alteration in valuable fisheries and the whole balance of aquatic life established through millennia—could easily turn out to be disastrous.

Standard treatment of pollution at its source consists of the primary and secondary processes we have glanced at, sometimes adjusted to specific industrial wastes. It has to be brought up to peak efficiency along the Potomac, for this is a "known factor" of great significance. Plants can and must be improved physically where necessary, and qualified operators provided for them. Collection systems have to be improved or enlarged in many places. Diminutive plants, doomed to inefficiency by their size and the financial impossibility of hiring expert workers for them, need to be eliminated in favor of regional waste collection and treatment facilities, which are quite feasible, particularly in the watershed units of the upper Basin.

Even so, it has emerged clearly to view in this Potomac study that standard treatment alone is no longer an answer in areas of concentrated or continuous population and industry, where the leftover wastes and the nutrients in the effluent from even well-run standard plants can often add up to a killing load for water.

Total diversion of treatment plant effluents is sometimes possible, but is subject to the same objections that apply to total diversion of untreated sewage—possible pollution of the receiving water (such as Chesapeake Bay or the lower Potomac estuary, both of which have been suggested and considered for Washington's effluent) and the alteration of hydrological and ecological conditions. Modified forms of effluent diversion, however, may offer more promise.

Effluents from maximum standard treatment processes, for instance, can be injected into underground strata as recharge water for aquifers—a process mentioned earlier as one alternative in the emerging package of water supply techniques—or may be spread over the surface of large areas of rural land where they serve as irrigation water and fertilizer combined, as well as soaking down into underlying aquifers. For large scale, sustained use, both of these practices still offer some technical difficulties—algae buildups that interfere with percolation, odor problems, limited aquifer capacities, the large amounts of land required for spreading, the effect of rain and freezing weather, and such things. And where the aquifers in question do not feed the original source stream system, a big subtraction is again involved. But for certain conditions in certain places these problems are undoubtedly going to be worked out.

A more modest but highly useful modification of effluent diversion is the spacing of treatment plant outfalls at intervals for a long distance downstream from a treatment plant. If nutrient and organic loads are not tremendously heavy in relation to the size of the receiving stream, this procedure can help to assure that no one stretch gets too strong a dose of them. It is likely to find good use in the Potomac and elsewhere, though only as an adjunct to the best available treatment.

* * * * *

"Advanced treatment" and "tertiary treatment" are becoming common terms nowadays. They refer to any of a considerable array of additional or intensified processes aimed at attaining levels of purification that would have cost an impossible price a few years ago. Most of them are still experimental and often still expensive, and they involve everything from filtration through powdered coal to flash distillation, with still others in prospect. Some bypass conventional treatment and deal with whole raw wastes. More build on conventional treatment and are designed to remove nutrients and residual organic material from its effluents. Of these latter approaches, at least one, involving lime precipitation and other processes to remove nearly all phosphorus and most remaining organic material, is nearing a stage of development and economy that may warrant important use. It will be applied first at the new Piscataway treatment plant of the Washington Suburban Sanitary Commission in Prince Georges County, Maryland, which will also incorporate research and demonstration projects in nitrogen stripping and other things.



In the long run such advances offer the main hope of clean water for a superpopulated future America, where volumes of wastes are going to be enormous and first-rate off-stream treatment is going to have to be the main way of handling them. Even where wastes can be collected easily for treatment, however, as in industry or in sewered populated areas, it may take a good many years to work out varied forms of advanced treatment adaptable to different sets of circumstances, at prices that communities can afford to pay—and a willingness to pay what can be paid is going to have to be a part of the long clean-up job ahead. Undoubtedly continuing research will work out such forms of treatment, but the research itself may be quite costly and no one can predict its pace.

Where waste sources are too diffuse to be channeled into collection systems—as along many agricultural streams heavily polluted through land runoff and drainage, and also in some urban situation—present tools are extremely limited. Soil conservation practices aimed at cutting down erosion—to be discussed within a few pages—tend to keep not only silt but nutrients and other substances on the land to some extent. Concentrated sources of animal manure such as dairies, poultry operations, and feed lots can be brought under some control by fencing stock off from streams and by techniques of lagooning and later field spreading, which need much wider use in the Potomac Basin. But even if these approaches were applied fully throughout the region within a shorter time than appears likely or even possible, land runoff would still be a heavy source of water degradation.

Hence it is probable that flow augmentation—sometimes called "flow dilution" or included in the broader term "flow regulation"—through the release of stored water, will be an important auxiliary tool in water quality management for a good while to come. This is not a form of flushing wastes downstream from their source and out of sight, as some opponents continue to insist, but a means of helping streams to oxygenate and decompose excess wastes by the same processes they have always used on natural and normal loads. On the other hand, neither is flow augmentation the end-all cure for pollution that enthusiasts of a few years ago claimed it to be. Its effect on slow masses of water is uncertain and probably minimal, and too much dependence on it even for flowing streams would obviously encourage neglect of the practical and moral need to keep filth and troublesome substances from getting into the streams in the first place. Furthermore, such dependence would lead rapidly to a point of diminishing returns, like the flood-plain development and protection cycle examined in the preceding chapter. Increases in populations and pollution would lead to a necessity to provide more and more augmentation of flows, with storage space in reservoirs becoming more and more expensive precisely as flood protection does. Flow augmentation is no substitute for good treatment, but a valuable adjunct.

In the record drought summer of 1966 the South Fork of the Shenandoah, heavily polluted with municipal and industrial wastes near Waynesboro, and with fertilizer, manure, and other substances in drainage from the rich and intensively utilized farm country through which it flows, ran very low for months. In many places it was slimy and unpleasant, and aquatic life suffered to some extent, but the picture was not nearly so dismal as it would have been if the river had not been helped out more or less by accident. The source of this help was some 2000 gallons of water per minute that the Merck plant at Elkton and the Dupont plant near Waynesboro were releasing after having pumped it out of deep aquifers and used it for cooling. If all sources of pollution had been receiving adequate treatment, this minimal dilution might not have been so badly needed to avoid the fish kills and algal stagnation and other results that would have ensured without it. But "all sources" include the problematic agricultural drainage, and for that matter the definition of "adequate treatment" is going to have to go up and up in our expansive future.

The sad situation of the smaller and much less industrialized Monocacy in the same summer underscores the point. The Monocacy flows through similar farming country and passes by a few towns. The largest of these is Frederick, Maryland, for whose approximately 40,000 people the little river furnishes water and a conduit to carry away the effluent from their average-to-good secondary plant. At times during that dry summer practically the entire flow of the river below Frederick consisted of effluent, with effects on stream life, esthetics, and the general surroundings that are not hard to imagine.

Another good example of a place where, under present conditions, augmentation could sometimes be used beneficially is at Great Falls and in the Potomac gorge below. Heavy public expenditure has protected the shore in much of this neighborhood and provided pleasant recreation areas whose main scenic focus is the violent magnificence of the river in its plunge. But the magnificence becomes a rather drab joke in dry summers when metropolitan withdrawals of water above that point shrink the river to a semblance of normal flow.



The North Branch and some smaller Basin streams also need this same kind of help and most will continue to need it even when the best economically feasible treatment of all collectable wastes entering them is ensured. It can be provided out of reservoirs, large or small, whose need for other purposes as well will keep the cost of dilution within reason. A future possibility, if research presently going on in the Basin verifies it and shows ways of putting it to use, is to employ ground water in the same way. There can be no doubt that if the flowing waters of the Basin are to be put back in good condition and kept that way under population pressures that are in prospect, flow augmentation in some places is going to be an important tool.

In the upper estuary, however, its usefulness appears to be far more limited. The plan proposed in the Army Report of 1963, in line with a Public Health Service approach emphasized in the 1961 Water Pollution Control Act, was designed to provide an eventual minimum flow into the upper estuary of 3100 cubic feet per second, or around two billion gallons per day, for the purpose of dealing with treatment-plant effluents and miscellaneous pollution. But more recent investigations have raised strong doubt as to whether such augmentation could do the job in the estuary with its huge volume of water, and its slow, tide-baffled currents that greatly lessen its assimilative capacity.

In terms of dissolved oxygen, dilution of such a body of water for quality improvement appears to decrease in unit effectiveness as the volume of dilution is stepped up, which means that past a certain minimal point of improvement it gets expensive and requires unreasonable amounts of storage. In terms of nutrients, one authority has calculated that about 20,000 cubic feet per second would be required to reduce the nutrient level in the upper estuary to a point where it would be only twice that of a normal and healthily "rich" section of the upper Chesapeake Bay. Some augmentation below the point of diminishing returns will undoubtedly be needed, not only for the estuary but to keep the river alive in its gorge above Washington during periods of low flow. But as a main tool for the metropolitan river, it will not substitute for achievement of the best possible standard treatment followed by advanced treatment and other techniques.

Obviously, just as in water supply, an ultimate cure for water quality ills is going to consist of a "mix" of solutions, different techniques being applied to the situations they are best suited to deal with, and combinations of them being worked out where combinations are what is indicated. Already the same kind of sophisticated mathematical models of given bodies of water—including the Potomac—that are being used to study solutions for water supply problems are being put to use on water quality as well, weighing the benefits and drawbacks of various combinations of means. And, just as in water supply, ultimate "hard" technology is undoubtedly going to make better solutions possible, while a strong and meaningful start is possible with the technology that is on hand.

* * * * *

Silt is a truly Basinwide problem. The individual tiny grains of soil that mass to sully and choke the estuary may have originated anywhere in the thousands of square miles of drainage above. They constitute an economic loss at their points of origin as well as a trouble all along their downstream course of migration.

The basic-physical ways of preventing silt are twofold and easily defined: first, the maintenance of proper land cover—vegetation or humus or mulch which blankets and anchors the soil particles and prevents falling or flowing water from dislodging them—and second, structural approaches that control the flow of water and can also serve to trap eroded material. These latter can be anything from good contour plowing practices to a major reservoir with a certain silt capacity built into it.



Such techniques are the basis of existing programs of the Soil Conservation Service and the Forest Service that have proved their effectiveness over many years of rural application. Watershed planning with small reservoirs, check dams, and terraces backed up by good land treatment and use, soil surveys, wise forestry practices, and such things are stimulated and bolstered in these programs by technical and financial assistance given to private landowners, States, and local organizations. They have already had important local effects in the Potomac States as throughout the country, but for maximum value in relieving sedimentation they are going to need much wider and more intensive application.

In modified form, they can be effective against newer and more concentrated sources of silt, while sometimes accomplishing other purposes as well. As we noted in discussing metropolitan pollution, urban land undergoing development can enormously benefit from good watershed planning. Preservation of critically erosive and flood-prone land in grass and forest, insistence on prompt re-vegetation of bared land and the use of such things as sediment detention basins by developers, the construction of small headwater reservoirs when they are needed to trap silt and reduce flooding—all these elements of watershed planning are effective not only against silt but against standard urban and suburban ugliness. The translation of rural techniques to city use cannot be literal, for both urban hydrology and urban land use are distinctive, and a good deal remains to be learned about making the techniques work better there. But their basic principles are obviously a main hope.

Other modifications of them, if put into wide practice, can cut down on the heavy production of silt by strip mines in the upper Basin; these involve both the reclamation of abandoned mines and the use of more care in scraping new ones. And application of the same principles—protective cover and detention of runoff—to new highway and road construction, as well as to the reclamation of banks and shoulders on old secondary roads, has to be achieved.

The silt already in the upper estuary, and likely to continue to be deposited there even after the best available controls may have been put into operation above, will need radical treatment. The tens of millions of tons already choking the metropolitan river, the stockpile of centuries, will have to be dredged out if the river is going to be as pleasant and useful at the capital as it ought to be, and so will the yearly additions that can inevitably be expected. This can be done if the money is available, though a considerable unsolved problem, under research at present, is where to put the silt after it has been taken out of the river, for appropriate fill sites are growing scarce.

Turbidity in the sluggish upper estuary will continue to be a problem too, for the fine particles of silt that cause it are the least affected by standard land treatment and sediment control measures. Polyelectrolytes—chemicals which when applied in quite small amounts can coagulate such suspended silt and settle it out—offer some promise as tools against turbidity and are being tried out experimentally above one of the reservoirs on upper Rock Creek, with good results thus far. Very possibly they may prove to be useful for clearing up the estuary after it has been roiled by storm runoff, and for achieving some control of murky waters around sand and gravel dredging operations. However, ironically, it has also been pointed out that until the excess of nutrients in the upper estuary is eliminated, such clearing of the water could very possibly cause a great increase in the already disastrous algae blooms, by allowing sunlight to penetrate to greater depths and foster more production of this undelightful greenery. Cleanup of pollution as complex as that evolved in the 20th century has to be across the board.



Barring a general philosophical revolution on the part of the American people, the problem of junk and debris in our waters is likely to continue and even to increase as people and their consumption of the products of the economy maintain their geometric growth. Clean rivers in themselves might deter a good many people from cluttering them thus, and so might public education, stiff fines, and the provision of better municipal pickup and dumping facilities. But mainly getting rid of such detritus is probably going to be a matter of fairly continuous gathering and disposal. On navigable waters like those of the upper Potomac estuary, ingenious collection craft under the command of Army Engineers are in prospect; elsewhere the job is likely to be more old-fashioned and laborious.

For certain remaining pollution problems, no definite full technological answers exist at present and the main hope must be to alleviate them as much as possible while pressing a search for long-run answers. Some are relatively restricted in their effects in the Potomac Basin so far, though they have some drastic local effects and some long-run implications. Certain industrial wastes not amenable to any presently known form of treatment, such as tannery discharges at Petersburg, West Virginia, and Williamsport, Maryland, are one example. So are the noxious exudations of raw sewage and garbage from ships and pleasure craft. Marinas themselves and the boats docked there can and must be connected to waste collection systems. Laws can and should prohibit discharges from watercraft in harbors and rivers. But until better means of on-board waste treatment or retention than exist at present are evolved and made mandatory, the multitudes of boats with standard toilet facilities are going to keep on causing trouble.

Other sources of trouble without clear-cut present solutions are big ones. Surface runoff from both cities and rural areas, as we have seen, causes much pollution. In the country, soil conservation measures can slow it somewhat and strain out some pollutants, and augmentation of streams' flow can enhance their capacity to oxidize the wastes. But neither of these seem likely to do much to ease the longrun buildup and diffusion of persistent pollutants like pesticides, or to avert the possibility of disastrous spills. Public education and wiser restrictive legislation may help, but the only real hope in terms of these poisons appears to be that more selective and less indestructible substitutes will be found, and all promising means of biological pest control explored. Continuing programs are focused on the problem, but it continues to be serious.

Pollutive runoff from urban areas merges with the whole question of urban sewer systems, for most of it gets to the river through storm sewers. We have seen that the old-style combined sewers of the District of Columbia and Alexandria cause gross pollution when storms force open their overflow gates, and we have seen too why the approach to this problem that formerly prevailed—the arduous, hugely expensive digging up of sewers and their replacement with dual pipes to carry storm runoff and sewage separately—is no longer considered satisfactory. For the more modern dual systems also contribute much trouble through the filthy rainwater that pours out into streams from the storm system and through the accidental or illegal channeling of sanitary wastes into storm sewers.

A wholly satisfactory answer would allow runoff water as well as all sanitary wastes to be held for full treatment at a standard plant. But when we consider that at the Washington metropolis the dirty local runoff from a single storm may amount to billions of gallons, the question of where to hold it grows a bit complex, and is leading toward experimentation with such ideas as vast subterranean networks of tunnels for storage. Partial answers might come from subjecting storm and mixed flows to different and lesser kinds of treatment by micro-screens at sewer outfalls, detention and settling tanks, and filtration beds. These possibilities and others need much investigation and testing.

Then there are the multitude of nasty mysterious dribbles that help to degrade Rock Creek and can undoubtedly be found in even more profusion along every other metropolitan watercourse. Such of them as issue from storm sewers will be eliminated when a solution turns up for the problem of runoff water. The others, and they are numerous, will not. Even if the bureaucratic and political tangles that help to perpetuate them—which will be mentioned again—are dealt with, the sheer mathematics of possibility in a great city, plus the frequent difficulty of fixing responsibility, make the overall problem of these miscellaneous leaks and dribbles a very tough one, not likely to be resolved with the wave of anyone's hand. Except in visible and well-defended watercourses like Rock Creek, they will probably persist for a long while, even though in reduced quantities, together with some storm runoff and some periodic discharge from combined sewers, not a major component in estuarial pollution but a stubborn one.

A final great contaminant against which weapons are meager is acid mine drainage. Its sources along the North Branch are numerous, as we have seen. They have been and are being minutely studied, but present technology does not furnish any clear and effective means of dealing with each source individually and returning the upper river and its branches to health, and such source rectification would be the only really adequate answer.

Surface strip mines are deservedly notorious for the destruction of the rugged green landscapes that are one of Appalachia's greatest resources. Because of the public disgust they arouse, they have had a lot of attention, and methods for conducting this sort of mining less brutally and for reclaiming old minesites have been worked out. These methods have notable effect on silt and acid production. Because State laws to regulate strip mining have been generally scarce and weak, however, and because the reclamation of old mines is very expensive, such action is mainly more honored in the breach than in the observance.

However, strip mines produce only a tenth to a quarter of acid mine pollution, and if they were all under control the problem would still be huge. The active or abandoned underground mines that give out the great bulk of the acid and other pollutive substances have so far almost totally resisted satisfactory management, despite tremendous efforts. Among techniques that have been tried are neutralization with limestone and other materials, air sealing to cut down on the oxidation that helps form the acid, sealing of mine openings to prevent outflow, mining methods designed to prevent exposure of sulfuritic materials, and chemical inhibition of acid generation. Regardless of the hope that some have aroused, none has worked well and economically, and the search is hindered by a continuing lack of data and scientific knowledge concerning the complex physical and chemical processes by which the pollutants are formed.

A number of agencies are researching this whole problem, among them the Federal Water Pollution Control Administration, the Geological Survey, the Bureau of Mines, the Soil Conservation Service, INCOPOT, and some State government bodies. Sooner or later an answer or a set of answers must come out of these efforts. But nothing presently conduces to a belief that the acid problem on the North Branch or anywhere else is going to find quick and dramatic alleviation at its sources.

Dilution of this acid pollution helps to minimize its effects, not actually neutralizing them but reducing their severity in periods of low river flow. It can be accomplished by impounding mine drainage for release only during periods of high flow, though where sources are many as on the North Branch this would be difficult. Or fresh water can be held in bulk storage for release during low flow. In helping acid conditions along the lower North Branch, therefore, the authorized Bloomington reservoir may play a part, though it will do nothing for the upper reaches of the river and the reservoir water itself will be acidic if nothing is done to neutralize it. Under INCOPOT auspices, a promising inquiry is being conducted into the possibility of instream acid removal above the reservoir, using an energy process possibly powered by electricity generated at the dam. If it works out as well as seems probable, the benefits can be huge.



There is little point, of course, in getting the acid out of the lower North Branch unless the other pollution in that area is dealt with too. This compounded trouble, involving a considerable number of towns and industries with insufficient waste treatment or none at all, is made to order for a pilot application of the regional or sub-basin type of waste management authority mentioned earlier in this chapter. Not only is the problem on the North Branch bad enough to warrant special overall measures, but the area's topography is well suited to collection of wastes and their conveyance to first-rate centralized treatment plants. This approach too is being studied out by INCOPOT, not only for the North Branch but for other well-adapted problem watersheds such as Antietam Creek. Like similar systems in Germany that have long been admired, it would pool the resources of all sub-basin waste producers, get appropriate government funding, and subject all the pollution of a given drainage area to intensive and comprehensive correction.

Machinery

Though its spread-out economic benefits are almost incalculably great, good waste management unfortunately is seldom a money-making affair for those who sponsor it. Therefore, it is not usually so much the concern of private enterprise as of citizens in general and the various levels of government that look after the citizens' desires and wellbeing. It depends on laws to back it up, and on institutions and programs established by law. These are the only machinery by which it can be adequately stimulated, unless we assume that all waste producers are altruistic to a point of self-sacrifice, an assumption which history does not encourage.

Thanks to thoroughly justified public anxiety over the state of American waters, there is presently on hand the best assortment of such legal machinery that has ever existed, much of it so new as to be mainly untested. The Key Federal item is the Water Quality Act of 1965, which established the Federal Water Pollution Control Administration and set into motion a national program to clean up interstate and tidal waters. In the program the States were allotted primary responsibility for setting standards of cleanliness and were given until June 30, 1967, to work them out and submit them to the Federal Water Pollution Control Administration for review. Later came the Clean Waters Restoration Act of 1966, which authorized funds for F.W.P.C.A. construction grants to help communities build waste treatment facilities. Programs under other government agencies are also aimed at helping towns and cities deal with wastes.

In May of 1966 the Federal Water Pollution Control Administration was transferred from the Department of Health, Education, and Welfare to the Department of the Interior, with a good many changes in personnel. A valuable move toward the longrun unity of Federal environmental study and action, this change has meant that the agency's shakedown period in its new surroundings has come during the latter part of our Potomac work, and that some large questions of policy and procedure are only now being answered. Furthermore, the fact that our study has coincided with the inevitably lengthy shaping of the State standards, and with their review and their coordination on specific interstate streams like the Potomac and its main tributaries, has somewhat blurred our view of this most significant legal machinery of all. For it is through these standards and their enforcement that the fundamental action toward a clean Potomac will be taken. The emphasis in formulating them and reviewing them has been on vast improvement, not on a rationalization of existing conditions, and behind them there is going to be legal muscle for enforcement.

Erosion and sedimentation, particularly from urban and industrial sources, will be of concern in these State programs, and in fact some Basin States already have powers for use against them that have never been brought fully to bear, but undoubtedly will be with the new impetus. At the Federal level, going programs of the Department of Agriculture—primarily under the Soil Conservation Service but also involving the Forest Service—are the best machinery we have. Their techniques of soil protection and runoff detention have been described earlier, and are often applied in a coordinated way to whole small watersheds. Mainly they are put into practice through the voluntary cooperation of landowners, watershed associations, and local or State governments, stimulated by Federal technical assistance and cost-sharing.

* * * * *

It was noted earlier that these techniques can also be effective against careless urban land shaping and other new concentrated sources of silt such as strip mines. But in terms of legal machinery, these areas present problems, chief among which is the matter of incentive on the part of those who must cooperate if the programs are to work. In an agricultural watershed, the effect of soil conservation practices and flood control measures on the health and productivity of the land is sharply evident to rural landowners and others in the neighborhood, who all benefit from it and usually are eager to cooperate. But strip mine operators and urban developers and road contractors and such folk seldom have to live personally with the erosion and mud and trouble that may result from the way they move earth and change the landscape. To them, sediment control and respect for the way watersheds work, even with cost-sharing, is likely to loom as simply an extra expense.

Under these circumstances, only stiff controls are going to make watershed programs and other devices work right. Local sediment ordinances are acutely needed, but are generally lacking or inadequate or poorly enforced, perhaps mainly because silt, in common with other pollutants, has some of its worst effects at points far removed from where it originates and local governments prefer not to stir up local developers and mine operators. It is a facet of what we called earlier the philosophical source of pollution.



This being so, the good of the Basin and the Potomac as a whole is going to require the exercise of State and interstate and Federal power against silt as well as against other pollution, especially around populated areas, until such time as the populated areas have developed the political maturity to take firm hold of their responsibilities in such matters. Laws and ordinances of themselves solve nothing. For example, many of the pollutive dribbles along Rock Creek and other metropolitan watercourses are based in clearly illegal practices and hence slovenly inspection and enforcement of existing regulations. Others occur because of defects in the sewer system that could and should be found and repaired. A shortage of manpower is one reason for such trouble, but poor philosophy is a bigger one.

States, interstate bodies, and municipalities, however, can exert no control over another and rather shameful set of pollution sources noted earlier in this chapter. These are the delinquent Federal installations in the Basin, generally but not always in the neighborhood of the capital, that are contributing to the river's problem. Recent publicity, much of it deriving from aspects of this present study, has been bringing about some improvement, as has President Johnson's Executive Order 11288, which directed that Federal facilities set the best example in the matter of pollution control. But the order has obviously not been obeyed with uniform enthusiasm in all quarters, defective philosophy and short waste-disposal budgets being no exclusive property of local governments. Sometimes this is because limited funds force agencies to put waste treatment far down on their list for spending, and little is left over for it. Whatever the reason in individual cases, a continuation of persuasion and enforcement by the F.W.P.C.A. within the Federal establishment is going to be essential, and Federal installations ought to be required at least to equal or excel the quality of treatment provided by other waste producers on the same streams or bodies of water. Furthermore, all the diverse pollutive activities dependent on Federal aid and cost-sharing—such as road construction, for instance—ought to be brought under similar controls.

* * * * *

Certain major changes in public policy are needed if different techniques of water quality improvement are to be combined in such a way as to give the most economical, appropriate, and effective protection to specific streams or river systems. The most important of these needed changes concerns the role of flow augmentation as a tool, for inclusion of water quality storage capacity in Federal reservoirs is a fairly new and uncertain practice, and some rather deep pitfalls are becoming evident.

One pitfall has to do with Federal Cost-sharing and the way it affects the freedom of choice of the States and localities on which the primary responsibility for eliminating pollution must rest. In building treatment plants to lessen the load of wastes discharged to streams, they can presently obtain Federal grants of up to 55% of the facilities' total cost. But if storage capacity for water quality—i.e., for flow augmentation—is provided in a Federal reservoir upstream, prevailing Federal policy based in a 1961 amendment to the Federal Water Pollution Control Act has been requiring them to pay nothing at all for it, though before such storage is authorized they must certify that an adequate standard of conventional treatment will be maintained downstream. Obviously, if this continues to be so, when the inevitable choice comes between improving on that adequate standard by investing in better treatment, either at the beginning or later, and seeking river dilution from a reservoir, they will be forced by sheer economics toward the latter, whether or not it is the right thing to do or in an overall sense the cheapest.

Like other aspects of flow augmentation already discussed, this situation is analogous to that of flood control, where communities have to pay a good part of the cost of local protection works or of controlling flood plain development, but can get reservoir protection free. In both cases, local authorities are stimulated toward choices that are not necessarily the right ones, taxpayers in general are forced to bear the weight of essentially local responsibilities, and the public may forever lose scenic or recreational amenities of great worth. The Department of the Interior, with a central interest in the problem, is taking the lead in an attempt to arrive at a better flow-augmentation policy that will permit right choices, put costs where they belong, and make certain that at the local level where pollution takes place there is sharp incentive to do something about it.

The other main difficulty has to do with the fact that river water has many uses, which augmentation may enhance or even stimulate. Water released from above during dry periods to increase and steady the river's flow and to help it handle wastes may also help navigation and hydroelectric power generation downstream, though neither of these is any longer a main factor in the flowing Potomac. Augmentation of flow can make the river prettier and more useful for recreation, and it can have stout beneficial effects on fish and wildlife. And under present conditions it constitutes a large increase in water of improved quality for free use by irrigators and industries and municipalities, which may so burgeon as a result that increased water consumption and waste production will cancel out the water quality effects of the reservoir releases in short order.

The need here, of course, is for some agency that can solidly guarantee that water released for quality control will be allowed to achieve that purpose and not be diverted to other uses that conflict with it. Where a river runs within a single State, and the State's constitution permits, the State may be able to adjust its powers of control and provide the guarantee. But where more than one State is involved, as on all the main rivers of the Potomac Basin, a good forceful river basin agency is clearly needed to coordinate water supply with water demand, and to ensure that benefits and cost responsibilities of any necessary reservoirs are meted out where they belong.

In terms of legal and institutional machinery, in fact, such a river basin agency is the most basic and urgent unfulfilled need along the Potomac, for the coordination and continuing supervision of water management in all its phases—assurance of supply, flood protection, quality improvement, recreation—in the vast physical unit of land drained by the river. And because land's condition is so often influential on the quality and utility of water, the agency's concern and authority must encompass some fundamental matters of land use as well.