Accumulating manure in a concentrated area, however, can be risky to the environment and to human and animal health. Facilities for manure stored in liquid form on the farmstead sometimes leak or burst, releasing large volumes of pollutants. Manure in earthen pits can form a semi-impervious seal of organic matter that does limit leaching potential, but seasonal filling and emptying can cause the seal to break down. Short-term solid manure storage and abandoned storage areas can also be sources of groundwater contamination by nitrates.
Manure can contribute nutrients and disease-causing organisms to both surface water and groundwater.
Nitrate can also affect adults, but the evidence is much less certain. Young livestock are also susceptible to health problems from high nitrate-nitrogen levels. Fecal bacteria in livestock waste can contaminate groundwater, causing such infectious diseases as dysentery, typhoid and hepatitis. Organic materials that lend an undesirable taste and odor to drinking water are not known to be dangerous to health, but their presence does suggest that other contaminants are flowing into groundwater. You can start protecting your drinking water supply from groundwater by completing an assessment of your livestock waste storage.