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11-6 the stream flows from the high mountains downstream through the foothi lis to the plains. Three main point wastewater discharges are located in the Basin. These are effluents from the municipal treatment plants for the City of Long- mont, the Town of Lyons and the Niwot Sanitation District. The City of Longmont Wastewater Treatment Plant discharges to St. Vrain Creek just below the confluence with Left-Hand Creek. The plant currently operates at about 80% capacity with an average dai Iy flow of 6.5 mgd. It is anticipated that the plant wi I I be expanded to approximately 14 mgd by the year 2020. Ammonia concentrations are a concern during low flow periods in the winter months and are currently restricted in the Longmont National Pollutant Discharge Elimina- tion System Permit. The Town of Lyons Wastewater Treatment Plant discharges to St. Vrain Creek just below the confluence of North and South St. Vrain creeks. The plant current Iy operates at 29% capaci ty wi th an average dai Iy f low of 0.085 mgd with no expansion anticipated at this time. The Niwot Sanitation District's Wastewater Treatment Plant dis- charges into a tributary of St. Vrain Creek at a point about 4 mi les northeast of Boulder Reservoir. The plant currently operates at 40% of capacity with no expansion anticipated at this time. In addition, minor wastewater discharges include a few mine dis- charges and the Jamestown wastewater treatment faci I ity into Left-Hand Creek. Currently, there are no land treatment systems and/or water rights exchanges using treated wastewater in the Study Area (Mugler, 1984, personal corrmunica- tion) . Current water qual i ty planning efforts in the-St. Vrain Basin are being undertaken by a task force comprised of state and local governmental interests, including the Denver Regional Counci I of Governments, the Larimerl Weld Counties Council of Governments, the City of Longmont, Boulder and Weld Counties, Colorado Division of Wildlife, EPA Region VIII, the Colorado Divi- sion of Water Qual ity, and the St. Vrain and Left-Hand Conservancy District. The task force is investigating whether current stream standards are being met, whether stream standards are proper or should be changed, extent of water quality problems and possible solutions, etc. In addition, water quality planning studies on St. Vrain Creek are present Iy being conducted by the Ci ty of Longmont and the EPA. 4. Stream Classification Water quality classifications of the State of Colorado are based primari Iy on the uses for which a stream is presently suitable or intended to become suitable. These classifications include recreation (Classes 1 and 2), agriculture, aquatic life (Classes 1 and 2 warm and cold water), domestic water supply, and existing high qual ity waters (Classes 1 and 2). Class 1 designations indicate a higher qual ity within particular usage category than I I I I I I I I I I I I I I I I I I I