Agenda - Planning Commission - 06/01/1999

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p~llutants, it is probably better to use separation requirements primarily to address odors and use performance standards or environmental regulations affecting management practices to address air pollution concerns. However, setbacks will serve to reduce some short-distance air pollution problems in the bargain. Water pollution concerns are a different question. Separation distances deal mostly with creating buffers between potential pollutants and water bodies like rivers, streams, lakes, and bays. As applied to CAFOs, these should include barring manure storage facilities from 100-year floodplains and setting minimum distances between such facilities and wetlands, rivers, creeks, streams, and inland lakes. Requiring the planting of filter strips along rivers, creeks, and streams, and establishing minimum distances from them for manure application to farmland, can help to reduce excess nutrient loading into water bodies. Chatham County requires a vegetative or tree buffer 50 feet wide between sprayfields and perennial waters, as indicated on U.S. Geological Survey topographical maps, and a 25-foot buffer for drainage ditches. Finally, preventing groundwater contamination requires reasonable separation from wells and shallow water tables. Chatham County prescribes a 500-foot distance from any wells for manure spraying. Keeping manure storage facilities at a safe distance from wells would be equally wise. Communities must consider applying these separation standards in reverse to new residential or other development to prevent potential complaints from coming to the nuisance. Such encroachment is not an uncommon problem at the fringes of metropolitan areas and must be addressed as fairly as the issue of CAFOs locating near long-time residents of Conditional Uses It is generally wiser to include conditions for CA.FO operation in the ordinance as explicidy stated requirements than az items subject to review after a proposal is submitted. Clearly stated requirements mean fewer surprises and more certainty in the process for both CA_FO owners and the public. If conditions have an appropriate place in the process, it is probably in dealing with less predictable aspects of the operation. For example, if incentives based on adoption of more advanced and effective designs or management systems are provided in the ordinance, a conditional use permit review could then be used to determine that the design or management system in question is the best available technology and will comply with expectations. In these cases, however, the guidelines controlling such decisions should still be clear enough to avoid the sorts of public controversy over individual feedlot proposals that arise when the rules are less clear. Performance Standards In a certain sense, many of the setback requirements relative to water pollution also double as performance standards. The quality that differentiates performance standards from many other features of typical zoning ordinances is that they often involve ongoing monitoring and enforcement of standards agreed to or imposed before construction of the facility was permitted or begun. This is the aspect of performance standards that puts special demands on enforcement staff for both time commitment and additional training. Odors are certainly the most problematic, but Harold J. Rafson, a nationally recognized expert on engineering for odor control, states that planners should not make the mistake of accepting industry arguments that measuring odors is a subjective exercise. Instead, he suggests that the human nose' is a highly refined organic instrument whose objectivity can be trusted with the right scientific methodology. The establishment of traditionally formulated odor thresholds may be the most difficult challenge in drafting a zoning ordinance with performance standards because the field of livestock odor control is so badly in need of further research. While it is technically possible to establish enforceable thresholds either at property lines or at set distances from specific suspect facilities, local officials should keep in mind that legally acceptable enforcement requires sending enforcement personnel to gather samples in order to establish evidence ora violation. The ordinance itself ought to be clear about the odor threshold that will result in the CAFO operator or owner being subject to a violation. (See sidebar for the new standards adopted in February by the Colorado Air Quality Control Commission.)