What is a special management area?

A Special Management Area is an area of the County where unique circumstances or contamination risk has resulted in MPH adopting specific regulations. There are currently four SMAs within Missoula County:

1. Missoula Wastewater Treatment Plant Service Area: This SMA is in place to notify property owners are within the boundary of City of Missoula planned sewer service area that the ability to use septic systems is limited.
2. The Rattlesnake Special Management Area: MPH applies additional restrictions in this area in order to better protect Rattlesnake Creek, which is a designated potential drinking water source for the city, in the instance that the existing groundwater wells are for some reason not viable. The rules limit density, require advance treatment systems in some areas, and prohibit further subdivision.
3. Roman Creek/Touchette Lane Special Management Area: This area has higher than average rates of bacterial contamination in drinking water wells. The rules limit density to one home per existing lot, prohibits further subdivision and imparts specific well construction and groundwater level monitoring requirements.
4. Seeley Lake Special Management Area: This SMA was established in 2015 to address significant nitrate contamination from septic systems. Creating the SMA was one of the formal ways MPH acknowledges that it is legally obligated to mitigate known contamination and is prohibited from taking any action, including writing septic permits, that might contribute to known contamination. Unlike other SMAs, the rules in this SMA do not directly prohibit new use, increased density or new subdivisions. Rather, they require advanced nitrate-removing treatment units be installed when a new or increased use is proposed.