The Clean Water Act: 31 years old and rivers are still used as giant urinals

October 18, 1972, thirty one years ago, it all seemed so easy, when Congress passed the Clean Water Act and Senator Muskie stated on the Senate floor: "This Act simply means, that we can not use our rivers any longer to treat our sewage".

Even tough many claim that this second largest federal public works program has been successful; neither of the Act's goals -- swimmable and fishable waters by 1983 and elimination of all water pollution by 1985 -- have been achieved.

Neither can they ever be achieved, because the regulations implementing the Act ignore 40% of the pollution caused by fecal waste and all the pollution caused by urine waste in sewage.  All this is the result of an incorrectly applied pollution tests.

This pollution test is called the BOD (Biochemical Oxygen Demand) test, which measures the oxygen used by bacteria that feed on the organic matter in sewage. Sewage contains carbonaceous matter (fecal), which is used by heterotrphic bacteria and nitrogenous matter (urine and proteins), which is used by autotrophic bacteria.

When the test was developed in England, around 1920, it was found that completing the test would take 30 days, but when applied on raw sewage, the autotrophic bacteria only contributed to the oxygen consumption after 6 to 10days. During the first 5 days, the test only measured the oxygen demand of the heterotrophic bacteria, called BOD5, while the proper name is C-BOD5.

The oxygen usage by autotrophic bacteria (N-BOD) also could be measured with another nitrogen test and the BOD5 test became a timesaver, but always intended to be used together with the nitrogen test.  When the BOD5 in sewage is measured 200, the total C-BOD is 300 and the N-BOD 200.

Although all this is well described in the old literature, it became common engineering practice worldwide, to solely use the BOD5 test value and consider this value to represent all the organic waste in sewage.

While writing the CWA in 1972, Congress was told that eliminating all water pollution was not possible, but that demanding "secondary treatment" -- considered 85% treatment-- would be a good step in the right direction.

Unfortunately, when EPA applied the 85% treatment requirement for its NPDES (National Pollution Discharge Elimination System) permits, EPA applied this requirement on the BOD5 test, which, as explained earlier, only measures 60% of the pollution caused by fecal waste and not any of the pollution caused by urine waste.

Since the BOD5 test does not distinguishes between C-BOD and N-BOD, it is not possible to evaluate the treatment efficiency of a sewage treatment plant, neither is it possible to establish a waste load on receiving water bodies.  Last but not least, since this test value-- still assumed to be C-BOD5-- is used for the design of a treatment facility, plants are designed to treat the wrong waste.

The results of one day proper testing in 1984, discarded an approved plan to expand Salt Lake City's sewage treatment plant which would have cost the city 135 million dollar.

Autotrophic bacteria -essential in the nitrogen cycle-will be present in sewers and sewage treatment plants and will exert a N-BOD when effluents of plants are tested. This will raise its BOD5 value, often higher than the 30 (85% of 200) as was required for the discharge permit and causing such plants to be out of compliance.

Not only that many cities and industries were fined, thus penalized for treating their wastewater better then was required, legal enforcement of the NPDES program was impossible.

EPA acknowledged the problems in 1984, but instead of correcting the test procedures, EPA allowed also the use of the C-BOD5 test, which is similar to the BOD5 test, except that a special chemical is added to kill the autotrophic bacteria.  Many sewage treatment plants, prior to 1984 out of compliance, got into compliance by adding this chemical to their test.

EPA, by administrative ruling, lowered the goals of the CWA from 100% treatment to a mere 40% treatment, without asking or informing Congress.

Although aware, several members of Congress do not want to take action, because they are told that demanding better sewage treatment is not necessary and would be very costly.  Reality is that sewage treatment technology already was available in 1972, which achieves 95% treatment of both C-BOD and N-BOD and is less expensive to build and operate than conventional sewage treatment, which actually was developed solely to control odors.

An anniversary, besides a celebration, should also be a moment of reflection.  After 31 year it is time to implement the Clean Water Act as it was intended and promised to the American public.