Alternative wastewater disposal systems reduce groundwater pollution by decomposing organic wastes or removing nutrients more effectively. Hand dryers reduce water and paper towel use, alternative treatments for cooling tower water reduce chemical use, and carpet tile allows modular replacement of worn areas. In screening products for this area, we focus on quantifiable environmental benefits and strong performance records.
Eco Bionics, a subsidiary of NCH Corporation, produces the BioAmp system for culturing bacteria to aid in wastewater treatment in municipal wastewater treatment plants and to control of fats, oil, and grease (FOG) in grease traps. The BioAmp system contains a fermentation reactor that creates about 30 trillion bacteria microbes (Pseudomonas and Bacillus) per day and introduces these to the treatment plant or grease trap automatically. Case studies presented by the company show FOG reductions of 69% to 89% and biochemical oxygen demand (BOD) reductions of 22% to 32%. There is also some benefit in reducing total suspended solids (TSS). Applications for grease trap installations include bakeries, dairies, breweries, food production plants, and large commercial kitchens.
The most appropriate wastewater treatment solution will depend on characteristics of the site and effluent. Both centralized (municipal wastewater treatment systems) and onsite systems are used, and there are big differences among products and systems within those categories. Primarily onsite systems are covered here, though some of these may be used in centralized municipal facilities.
A properly designed, installed, and maintained onsite system can do at least as well with nutrient removal as a centralized (municipal) system while providing groundwater recharge. However, conventional onsite wastewater treatment systems—septic tanks and leach fields—typically introduce the nutrients in the wastewater (nitrogen and phosphorous) directly into the groundwater, causing aquifer an surface-water contamination. Failed onsite septic systems are the cause of many water-quality problems.
Various alternative systems provide some nutrient removal, but may cost more up-front, use more energy for pumps and aerators, and have increased maintenance requirements. Some plastic-matrix products incorporate recycled content. A well-designed system will use the least intensive option capable of providing effective treatment and nutrient removal for the site.
For more information the National Onsite Wastewater Recycling Association (NOWRA) and 2002 US EPA Onsite Wastewater Treatment Systems Manual, are good places to turn. The National Environmental Services Center (NESC) staffs a hotline for questions on onsite systems.
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