Load Allocations

The Bear Creek Reservoir Control Regulation #74 incorporates the total maximum annual load (TMAL) that controls total phosphorus wasteload allocations for point sources and the allowable nonpoint source load for the Bear Creek Watershed. The TMAL, which is consistent with a total maximum daily load, results in the Bear Creek Reservoir meeting designated beneficial uses and classifications as listed in the South Platte River classifications and standards regulation #38. The reservoir has a narrative standard based on established trophic indices. The TMAL describes prohibitions, standards, concentrations, and effluent limitations on the extent of specifically identified pollutants that may discharge into the watershed. The elements of the Bear Creek TMAL as approved by Region VIII Environmental Protection Agency and the Water Quality Control Commission are shown in Table 1. Mean annual concentrations of selected parameters used to determine compliance with the TMAL are shown in Table 2. The total wasteload allocation for all point sources of phosphorus in the Bear Creek Watershed is 5,255 pounds per year. Each individual discharger in the Bear Creek Watershed is limited to an annual wasteload of total phosphorus, which can’t be exceeded, except as provided through trading provisions. Point source discharges can’t exceed a total phosphorus effluent concentration of 1.0 mg/l as a 30-day average except as provided in trading provisions. All point source dischargers are required to meet the 1.0 mg/l total phosphorus concentration effluent limitation as a permit condition and this data has not traditionally been provided to Association. The Association annual reports provide more information on compliance and reservoir trends.

Total Maximum Annual Load (TMAL) = Wasteload Allocation + background Sources +Margin of Safety (MOS).
Table 1 Bear Creek Watershed TMAL Elements

Allocation	Endpoints	Target
Point Source Wasteload Allocation	Total phosphorus effluent poundage limit	The total wasteload allocation for all point sources of phosphorus in the Bear Creek Watershed is 5,255 pounds per year. Each individual discharger is limited to an annual wasteload of total phosphorus (pounds per year), except under trading provisions. Reserve pool maintained for future dischargers.
Point Source Wasteload Allocation	Total phosphorus effluent concentration limit	Point source discharges can’t exceed a total phosphorus effluent concentration of 1.0 mg/l as a 30-day average, except under trading provisions.
Margin of Safety (MOS)	Implicit MOS	A margin of safety is built into the wasteload and nonpoint source allocations as an implicit MOS.
Nonpoint Source Load Allocation	Reservoir narrative standard	Jefferson County, Clear Creek County, Park County, municipalities, and districts in the Bear Creek Watershed will implement best management practices for control of erosion and sediments.
Nonpoint Source Load Allocation	Monitoring trophic status indicators	At a minimum, local entities in the watershed will ensure that water quality monitoring is conducted on Turkey Creek, Bear Creek, and in Bear Creek Reservoir on a monthly basis to measure the phosphorus loading reaching the reservoir and other factors which affect the water quality, as well as the attainment of beneficial uses for the reservoir, including meeting the reservoir narrative standard. Data results must be reported to the Water Quality Control Commission and Water Quality Control Division.

Bear Creek Watershed Association

The Bear Creek Watershed Association protects and restores water and environmental quality within the Bear Creek Watershed from the effects of land use