Biosolids
The waste created by human beings, especially in the cities and suburbs, and the waste produced by the huge meat and dairy industries necessitate inventive answers before we pollute are waterways and oceans and landfills with organic material that can be reused. By not reusing this material we are taking away, year by year, nutrients from the nutrient cycle and placing them somewhere else that is poisoned by them or does nothing with them. This facilitates a greater dependency on fertilizers which feed crops directly without adding to the soil anything sustainable.
Cities used to get rid of their sewage and sludge at sea and landfills. The seas developed dead zones that had been depleted of oxygen and an international ban was instigated in 1992. Landfills can disrupt and disturb the underground water system. If they do not leak, they effectively seal this material from use. The other form of disposal was burning the treated product. This smells awful and shifts the dumping burden from the earth to the atmosphere. In the 1970s, the EPA began looking into alternative ways to handle the nation's sewage.
The idea to redistribute sludge onto farmland makes sense on many levels and was adopted by the EPA as a means to handle municipal waste. However, it does not appear enough research was done into the grades of sludge being used and the effects this has on the communities involved in these programs. In more cases than not, class B sludge was used, though 95% free of pathogens and heavy metals, many accounts arose of ill effects on people. Class A sludge is 99.9% pathogen free with a very low heavy metal count as well. It is virteously odor free and mixes well with soil. However, because class A sludge undergoes more processes, it is not as rich in nutrients as class B sludge.
The benefits of a safe biosolid project would give credence to the name change. Biosolids have a high level of organics, it is rich in nitrogen and phosphorus. It acts as a soil enricher rather than fertilizer with applications lasting between seasons. It feeds essential soil micro organisms and increases the soil's water holding ability. The negatives of sludge, first and foremost, is that it carries pathogens harmful to humans like: salmonella, Shigella bacteria, hep A, giardia, and parasitic worms. The other real problem is the presence of heavy metals. The heavy metals are present because many water treatment plants are treating water from combined sewer systems which mix human waste with municipal storm runoff which includes the vast amount industrial waste dumped into the enviroment.
An intelligent and well funded project can make class A sludge available as the biosolid used in soil upgrade. As long as there are no restrictions on class B sludge being used and little effort is put into studying the effects of its use, the future of biosolids will have to fight the image that they may be operating a form of a dump site. This would be a shame. As our population grows, we will have to find innovative ways to maximize what we use and minimize what we waste.
