Minnesota Pollution Control Agency

Media contact: Forrest Peterson, (320) 214-3789 Technical contact: Larry Gunderson, (651) 297-3825 ST. PAUL, Minn. -- The Minnesota Pollution Control Agency, with assistance from an advisory committee, has developed a plan to help improve water quality in the lower Minnesota River by increasing dissolved oxygen during low-flow periods. The plan targets phosphorus as the main cause of low dissolved oxygen, which can kill aquatic life. The plan identifies four pollution sources: wastewater-treatment facilities, direct discharges of sewage, stormwater and agricultural runoff. All contribute phosphorus, a nutrient that feeds algal growth. Low dissolved oxygen can result from bacteria consuming decaying algae. During low flow, wastewater discharges have the greatest impact compared to the other sources. The plan is the result of a Total Maximum Daily Load study for the lower 22 miles of the Minnesota River. The lower Minnesota River does not meet the standard for dissolved oxygen (5 milligrams per liter) during low-flow periods. The TMDL study determines the causes and suggests possible solutions. The implementation plan lays out the strategies to meet the goals of the TMDL. A 45-member advisory committee representing agriculture, cities, watershed projects, and environmental groups helped MPCA staff prepare the TMDL study and propose solutions in the implementation plan. Wastewater-treatment Facilities: Forty of the 143 permitted municipal and industrial wastewater-treatment facilities that discharge to the Minnesota River Basin have the greatest impact. The goal is to reduce total phosphorus from these facilities by 35 percent by the year 2010. To reduce the total amount of phosphorus, the MPCA is implementing a new basin-wide phosphorus permit. Expecting all wastewater-treatment facilities to make expensive upgrades may place undue financial burden on individuals in small communities where phosphorus contribution may be small already. To get the most gain for the least cost, the basin-wide permit includes provisions that allow small communities to benefit from phosphorus reductions made by some larger facilities. In some cases, it is less expensive for a small community to pay a larger community to use some of its excess waste-treatment capacity. Stormwater: Communities, industries, construction sites and others needing a stormwater permit already will submit Stormwater Pollution Prevention Plans as part of permit requirements. Those located in the Minnesota River Basin will be required to address phosphorus reduction in their plans. Nonpermitted communities will rely on education and voluntary measures to reduce phosphorus. Direct Discharges of Sewage: This includes septic systems that illegally discharge untreated or under-treated sewage that can find its way to a ditch, stream or other surface water. These may be individual septic systems or groups of systems -- such as one of the 13 unsewered or under-sewered small communities in the basin. To reduce phosphorus from this source, failing systems must be located and fixed. Financial assistance and loans will be used to encourage and enable homeowners and small communities to do this. Agriculture: Cropland is also a source of phosphorus. During low-flow conditions, there is little rainfall and most rainwater soaks in rather than running off the land. Leaving crop residue and protecting open tile intakes, or equivalent practices, will be encouraged. Since runoff is limited during low-flow times, the benefits of these practices will be to reduce runoff and keep soil on the land. The implementation plan allows 10 years to do the work for most activities. Due to replacement costs, it allows up to 20 years for stormwater system improvements in urban areas. The plan follows the Lower Minnesota River Dissolved Oxygen TMDL Report, which was approved by the U.S. Environmental Protection Agency in September 2004. For more information about the implementation plan, contact Larry Gunderson, Minnesota Pollution Control Agency, 520 Lafayette Rd. N., Saint Paul, MN 55155; e-mail larry.gunderson@state.mn.us; phone (651) 297-3825. The TMDL report and draft implementation plan are available on the Web at hhref="/water/basins/mnriver/mnriver-tmdl.html.