Liquid Manure Systems Research Articles

Health and safety implications of alternative energy technologies. I. Geothermal and biomass

An evaluation of potential occupational and public health aspects of geopressure, hydrothermal, hot dry rock, silviculture, crop and animal residues, fermentable plant products, municipal waste, and plantation energy technologies has been performed. Future development of these energy options in the United States will contain hazards that could easily be eliminated by safer equipment design and common-sense attention to operation and maintenance. Occupational exposure to hydrogen sulfide gas occurs near all geothermal sites and wherever organic matter decomposes anaerobically. Respiratory damage has occurred to laborers in geothermal fields, while farm workers have been fatally overcome when employed near agitating liquid manure systems. However, the most frequent and severe of reported injuries to geothermal workers is dermal exposure to caustic sludges produced by H2S abatement systems.

Death Caused by Fermenting Manure

FARM workers are at risk of contracting a unique set of occupationally related illnesses.^2,3Chemical toxicity is usually pesticide related but is also seen in settings like silage storage where toxic gases can be released. In contrast, manure handling has involved little chemical exposure except for that experienced through the nasal route. We present information to document how conversion of waste management units to more efficient liquid-manure systems can result in an increased risk of toxic chemical exposure. <h3>Report of a Case</h3> A 16-year-old farm worker began using high-pressure hot water to clean manure from gutters inside a recently emptied calf barn in Wisconsin. He was 10 m from a 378,500-L underground liquid-manure storage tank, the contents of which had been agitating for 30 to 60 minutes (Figure). After ten minutes he began to cough, vomited, collapsed, and died. A co-worker who was working close to an exhaust fan

Ground‐Water Pollution Aspects of Land Disposal of Sewage from Remote Recreation Areasa

ABSTRACTLocal ground‐water pollution problems are often associated with disposal of sewage from remote recreational areas. Ground water in these areas is routinely used for domestic purposes without treatment. Sewage treatment facilities are often prohibitively expensive. Transporting sewage to municipal sewage treatment facilities is often equally costly, or adequate facilities are not available.A soil incorporation method was tested at two field sites in Michigan's Upper Peninsula to evaluate its impact on ground‐water quality; Liquefied campground sewage was injected at 15 cm (6 in.) depths using a liquid manure system. Average dosage levels were 2.7 metric tons per hectare (1.2 ton/acre) of dry sewage solids. The application rate was equivalent to a fertilization rate of 116 kg/ha (104 Ib/a) of total nitrogen. Field tests were conducted on adjacent strips of Kalkaska sand soils in 1973, 1974, and 1975.Changes in ground‐water quality in the zone immediately beneath the water table were evaluated by analyzing samples from randomly located wells. Test wells were located directly beneath the treated area and up to 30.5 m (100 ft.) away in the direction of ground‐water flow. Nitrate levels in ground water at 3.6 m (12 ft.) depths were higher than control levels from the treated zone to the limit of the test well sampling. Levels of nitrate did not exceed the limits for potable water (10 mg/1 NO3‐N). No fecal coliform organisms were detected in ground‐water samples. Laboratory tests of the filtration capability of the A and B horizons indicated a high level of filtration of polio virus.Fertilization with sewage increased the biomass of native herbaceous vegetation by 410 percent. Nitrogen content of the treated vegetation was 63 percent above controls. Approximately 48 percent of the added nitrogen fertilizer was incorporated in herbaceous foliage at the end of the first growing season.Site selection guidelines for use by National Forests include remote location of incorporation sites, no potable‐water sources within one‐half mile downgradient from the site, infiltration rates between 5 and 25 inches per hour, slopes less than 5 percent, and dosage rates which will not exceed 50 kg/ha (56 lb/a) of mineralized nitrogen per year. Injection depths should provide complete soil coverage but sewage should be placed above the B horizon for maximum use of nutrients by plants.The soil incorporation method has been approved for selected sites by the Michigan Department of Natural Resources and the U.S. Environmental Protection Agency, with ground‐water monitoring required at each site.

Odor Reduction for Liquid Manure Systems

Odor Reduction for Liquid Manure Systems