No abstract

The current federal sludge regulations for the first time place limitations on the concentration of pathogens or indicator organisms in sludge and sludge products destined for distribution and marketing and land application. However, there is a general lack of data for assessing the impacts of these new limits on the wastewater industry. To understand better the extent of the compliance problem and the factors that may enable publicly owned treatment works (POTWs) using anaerobic digestion to comply with the new criteria, a survey of treatment plants around the U.S. was undertaken. In addition to data on fecal coliform densities in raw and digested sludge, information was collected on the design and operating characteristics of the 54 digestion facilities that participated in the survey. Based on the analysis of survey responses, it appears that the pathogen reduction criteria under the regulations are not unreasonable and should be achievable by most conventional anaerobic digestion facilities.zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Water Environ. Res., 66, 255 (1994).

Granular filtration and diatomaceous earth filter runs with a variety of coagulant aids removed chrysotile and amphibole forms of asbestos from Lake Superior water. The information gained from the tests was used in the design of a new 30‐mgd treatment facility.

Perhaps for the first time in the United States, the Haberer process was shown in a Shreveport, La., pilot unit to be capable of flocculating and removing solids from a turbid surface water (contact flocculation) and of simultaneously treating the water with powdered activated carbon (PAC) to remove soluble organic compounds. The overall reduction in trihalomethane formation potential was 63–66 percent when PAC was used in the system, but it is expected that even greater reductions could be achieved if either the type or the dosage of PAC was optimized.

The 1986 amendments to the Safe Drinking Water Act will substantially affect the treatment and supply of drinking water in the United States. The effects may range from minor operating changes to abandoning treatment and supply in favor of purchasing finished water from a neighboring community or water company. In all cases, the amendments will increase costs for water utilities and, ultimately, their customers.