Natrona County is home to nine (8) waterbodies that are listed on the Wyoming Department of Environmental Quality's 303(d) Report for selenium impairment, including four ponds or reservoirs (Rasmus Lee Lake, Goose Lake, Illco Pond, and Thirty-three Mile Reservoir), and four drainages or creeks (Poison Spring Creek, Oregon Trail Drain, Poison Spider Creek, and Casper Creek).  The North Platte River was listed in 1998 but removed from the list in 2018 due to the work completed by the NCCD and its partner agencies and landowners.  See the SUCCESS in the North Platte River page for more information.

Section 303(d) of the Clean Water Act requires that states identify and list waters for which the effluent limits are not effective in attaining designated uses. The Clean Water Act requires that states develop a separate Total Maximum Daily Load (TMDL) for each pollutant/segment combination on the 303(d) list and prioritize waters based on the severity of each pollutant/segment combination or listing. TMDLs are to be completed on these impaired waters "to assure the protection and propagation of a balanced, indigenous population of shellfish, fish and wildlife, and allow recreational activities in and on the water". Each state must submit a 303(d) List of Impaired Waters to USEPA every two years. For past and present Integrated 305B and 303D Reports, click HERE.

In 2009, the Wyoming Department of Environmental Quality (WDEQ) implemented an assessment project to develop selenium Total Maximum Daily Loads (TMDLs) for impaired waterbodies in the North Platte River Watershed. The purpose of the assessment was to analyze existing data, characterize water quality problems, assess sources, allocate loads, calculate TMDLs, and define management measures for selenium in the watershed.  The selenium TMDL for the North Platte River was developed in accordance with Section 303(d) of the federal Clean Water Act and guidance developed by the U.S. Environmental Protection Agency (US EPA). The TMDL was submitted to the WDEQ in September 2011. The TMDL addresses selenium watershed impairments near Casper Wyoming between Alcova Reservoir and the confluence of Muddy Creek with the North Platte River. 

Following the recommendations from the North Platte River Watershed TMDL Implementation Plan, grants have been obtained through WDEQ's Non-Point Source 319 Task Force to minimize selenium transportation and improve water quality in the watershed.

North Platte River Watershed

TMDL Implementation Plan - Segment 1

2012 - 2015

The North Platte River Watershed TMDL Implementation Plan - Segment 1 built upon the past accomplishments in the Kendrick Watershed Project and initiated actions outlined in the North Platte River TMDL.  The goals of this project were to increase landowner and agency collaboration in regards to the overall levels of selenium in our waterbodies, including local citizen leadership and guidance; implementation of BMPs in the Kendrick Watershed Project; continued water quality monitoring and analysis of selenium levels in the North Platte River Watershed to evaluate the effectiveness of the BMPs; and continued educational opportunities and materials to the landowners regarding selenium in the North Platte River Watershed.

During the course of this project, and in coordination with participating landowners and irrigators, the Natural Resources Conservation Service (NRCS), and the Casper Alcova Irrigation District (CAID), 17 Best Management Practices (BMPs) were completed. A total of 726 acres were converted from flood to sprinkler irrigation, 29,569 feet of underground water conveyance was installed, replacing 35,519 feet of earthen ditch. These projects provided opportunities for partnership building between agencies, as well as landowners. Within Segment 1, partnerships were established with NCCD, CAID and NRCS that will allow for many future project collaboration opportunities. Natrona County Commissioners and the City of Casper have also partnered with NCCD to complete selenium reduction projects in the Kendrick Project area.