Sewage Treatment Plants vs. the Environment

Abby Rockefeller

1. Conventional wastewater treatment systems (both on-site septic systems and centralized collection and treatment) are not designed to produce usable end-products. Failure to solve the overall problem of pollution caused by the waste materials received by these systems is, thus, a function of their design.

2. Spending any resources--money, time, energy, materials--on the extension of central treatment, either of the sewer lines and hook-ups or of the level of treatment, should be understood to be nothing more than a waste of all those resources. The time, money, and energy should be spent instead in developing an understanding of what solving the problems now caused by these "wastes" really means and in developing a long-range plan (necessarily educational as well as technical) to accomplish this.

3. Pollution prevention, reuse of industrial chemicals, sewage reduction, and water conservation should be maximized. Only thorough source separation can make instead of "wastes" products that are environmentally benign: organic products that are life-compatible; heavy metals and toxic organic and inorganic materials that are containable and reusable within the industries from which they come. It is by the same means also--by the conversion of "waste" materials to usable products at the point of generation--that both the immense economic and environmental costs of central treatment can be avoided.

To Sewer or Not to Sewer
Given that sewage--and sewerage--is a present fact, the question is what to do now? There are two courses before us.

The Path Not to Take
We can continue directing all the effluent from a given sewered community to a central point where a treatment plant (as advanced as we can afford) attempts to separate (as completely as possible given the unpredictable ingredients of sewage) the water from everything else that is in the sewage. However, leaving aside for a moment the immense energy and economic costs of this option, there is the enormous though little publicized problem of the production of sludge. Simply put, the more advanced the treatment of the sewage, the more sludge will be produced, and the worse--the more unusable and dangerous--it will be. The "better" the treatment, (i.e., the more successful the separation) the greater the range of incompatible materials that will have been concentrated in this highly entropic sticky black goo.
Because what goes down drains can never, either in quantity or in kind, be predicted, what may be found in sewage sludge is inherently unpredictable. (This has been demonstrated to be true even in the case of strict industrial source separation.) There is, therefore, no such thing as safe "disposal" of sludge. If landfilled, it will contaminate the groundwater. If incinerated, it will cause serious air pollution. When dumped in the ocean (amazingly permitted by EPA until 1989), it will cause--and has caused--great harm to marine ecology.
And "land application," the latest disposal tactic, may be the most insidiously dangerous of all.
Proclaiming sewage sludge to be a "fertilizer" and spreading it on farm land is, since the ban on ocean dumping, the cheapest means of disposal. This practice will certainly cause--sooner or later--contamination of agricultural soils by the countless non point-source (e.g., from unfocussed origins such as road run-off) and point-source (e.g., from industries whose discharge pipes are evident) toxic chemicals which have entered the sewage and come out in the sludge. And there is, therefore, the certainty--sooner or later--of toxic effects on crops as well as on the consumers of these crops. Beyond this there is the catastrophic damage that will also certainly be done to other life forms as these persistent toxics move up the food chain. It is also a highly effective way of "laundering" toxic wastes: there will be no discovery of the dumpers of industrial toxic wastes; the polluters of the Love Canals or the Woburns will go unpunished when their wastes are hidden in farm land, in crops, and in us. In short, sludge, the product of the central treatment of sewage is a hazardous waste and must be recognized and treated as such.

An Interim Plan of Action
The other direction to take, the one proposed here, has two parts.
First, in the thousands of communities around the country with groundwater polluting septic systems--just don't sewer. Instead, use Clean Water Act funds to install on-site remediation technologies, of which there are a number already on the market that are technologically superior to the septic system in their ability to accomplish pollution prevention or abatement. The advantages of this sewer avoidance program are great:
a) pollution problems can first be dealt with locally--where they really exist, and where they are worst;
b) the capital as well as the maintenance costs are always much less for on-site systems than for central sewering and treatment;
c) most importantly, the problem of water pollution becomes solvable instead of merely movable;
d) and, finally, development of communities is not bound to the rigid grid of sewer lines.
Second, in those cities and towns already sewered, implement a back-off-the-sewer program. That is, begin the process of intercepting--and recovering for recycling--the resources (the constituents of what we call "waste") as close to the source as possible. This does not mean shutting down existing central treatment facilities now: rather, it means the implementation of a legislative mandate to fund the use of existing technologies that can accomplish separation, recovery, and recycling, at the source. The objective of this approach is gradually to reduce the range and quantity of materials entering the sewage stream in order to decrease by degrees the burden on central treatment facilities and, thereby, the volume of sludge produced.

The implementation of such a program will, by its nature, be slow; but it can be started now on the conceptual, investigative, and legislative levels. Here are some key parts to this approach:
1. Do not extend any sewer lines to presently unsewered dwellings, institutions, or commercial facilities. Local pollution of groundwater is not, overall, more environmentally destructive than the massive relocation of pollution caused by central treatment outfalls of partially treated effluent or the dumping, burning, and land application of sewage sludge. We must remember that, when we agree to pay for sewering and upgrading the level of central treatment, though we may have improved the quality of a local body of water, the environment somewhere will still pay a heavy price--in direct proportion to the amount of pollution from which we have saved the water that we undertook to protect. We will have paid only to move the problem. Money now allocated for the extension of sewer lines should instead be saved for implementation of systematic source reduction, source separation, and low-entropy resource recovery technologies.
2. Upgrade the level of treatment in those plants in which immediate pro-tection of the recipient body of water is deemed, after real consideration of the implications, worth the economic cost and the environmental damage to be incurred by the increased creation of sludge.
3. Immediately implement a program of industrial point-source separation. Because adequate data concerning industrial processes are readily available, it is easy to apply specific source separation techniques to industrial wastes. It is, correspondingly, relatively easy for regulatory agencies to monitor industrial discharges. The problem is political: mustering the political will to oblige each industry to pay for collection systems and processing systems for all the chemicals used or produced by it which are deemed toxic or otherwise harmful to the environment.
4. Institute a ban on the use in consumer goods of substances that are toxic or otherwise damaging to the environment. Such legislation should include manda-tory reuse of toxic materials which don't themselves constitute part of consumer products, but are used in industrial processes.
5. Prohibit the use of garbage grinders. It is as irrational to use water to transport food wastes as it is to use water to transport human excreta or industrial wastes. Water should be used only for drinking and for washing.
6. Beginning at the periphery of sewered communities whose central treatment facilities are already overloaded, install composting systems designed to convert to humus--on-site---organic toilet "wastes" and food residues from kitchens. This would intercept the great bulk of organic "waste" materials at their source, preventing them from ever entering the sewage stream. Crucial to this element of the "back-off-the-sewer" plan is recognition that the products of the on-site composting toilet can--and should--be treated as useful, recyclable resources.
7. Remembering that centralized treatment of sewage creates the worst land-use conditions, start the necessary legislative work to develop environmentally sound land-use planning policies. This means also putting an end to the use of the pollution caused by septic systems as the de facto method of controlling development in unsewered areas.

Central collection and "treatment" of sewage can never solve the problem of water pollution. It will only create ever more complex pollution problems to solve. Sludge, the product of the latest bad technocratic choice in a long sequence of bad technocratic choices, will, if permitted to be passed off as a "fertilizer," inevitably have disastrous effects both on the agricultural soils to which it is applied and on the ecosystems connected to those soils. Biologically-based on-site pollution-prevention and recycling technologies are available now and should be a federally funded choice for the communities of this nation. Effecting such a sewer avoidance program will require the addition of an amendment to the Reauthorization Bill of the Clean Water Act.

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© 1997 The ReSource Institute for Low Entropy Systems