Twenty percent are classified as buffer zones bordering ship channels, and most of the remainder is classified as restricted due to proximity to wastewater outfalls. Mississippi did not report on the condition of wetlands. Ground Water Quality - Not reported in a quantifiable format or unknown. Extensive contamination of drinking water aquifers and public water supplies is uncommon in Mississippi although localized ground water contamination has been detected. The most frequently identified sources of contamination are leaky underground storage tanks and faulty septic systems.
Brine contamination is also a problem near oil fields.
Little data exist for domestic wells. Mississippi also expanded its definition of waters of the state to include wetlands and ground waters. Programs to Assess Water Quality Historically, the state annually sampled about 25 of their 57 historical fixed monitoring stations on a rotating schedule. The state has been able to significantly expand its fixed monitoring network to 143 stations statewide. The state now monitors physical and chemical parameters monthly, metals in the water column quarterly, and biological parameters once a year.