CATEGORICAL EXCLUSION DETERMINATION - City of Casper, North Platte Sanitary Sewer Rehabilitation Project

Wyoming Department of Environmental Quality  | view as a webpage

Wyoming Department of Environmental Quality


For the City of Casper North Platte Sanitary Sewer Rehabilitation Project
Natrona County, Wyoming

The Department of Environmental Quality/Water Quality Division (DEQ) has conducted a review of the proposed City of Casper North Platte Sanitary Sewer Rehabilitation (NPSS) project in accordance with EPA and State of Wyoming procedures for implementing the State Environmental Review Process. DEQ has determined that this project is eligible for a categorical exclusion. Accordingly, DEQ is exempting the project from further substantive environmental review requirements under the State Environmental Review Process. Neither an Environmental Assessment/Finding of No Significant Impact nor an Environmental Impact Statement /Record of Decision will be required for the proposed action. The following is a brief description of the situation and the proposed action and a brief statement of how the action meets the criteria for a categorical exclusion.

The project involves design and construction of improvements needed to address severely corroded sections identified in a sewer condition assessment of the NPSS Interceptor sewer. The City intends to use loan funds from the Wyoming Clean Water State Revolving Fund (CWSRF) administered by the Office of State Lands and Investments (SLIB). Based on current estimates, the City plans to borrow an amount of $8,000,000 from Wyoming’s CWSRF program. Loan repayment will come from user fees, system investment charges, and/or fund reserves. Actual user fee increases have yet to be determined, but are estimated to be $1.28/month per user if no reserves are used. The terms of the loan are 2.5% interest rate, 25% principal forgiveness, and 20 years duration.

The City of Casper is aware of and accepts the fact that they will be responsible for any required mitigative actions associated with and including storm water runoff, erosion control, archeological/historic artifacts, and air quality concerns. These will be part of the standard State Revolving Funds Program contract conditions.

DEQ is granting an exclusion because this project replaces or rehabilitates existing infrastructure. This project will be completely constructed in previously disturbed ground, specifically ground disturbed by a previously installed sewer. DEQ has determined that exempting the proposed project from further review under the State Environmental Review Process will not result in adverse impacts to the population or the area of the City of Casper and Natrona County, Wyoming.

The documentation to support this decision will be on file in the DEQ Cheyenne Office and is available for public scrutiny upon request. Comments concerning this decision may be addressed to Stan Miller, SRF Project Engineer, Department of Environmental Quality, 200 W. 17th St., Suite 200, Cheyenne, WY 82002, Tel. (307) 777-6371-3471, FAX (307) 635-1784, email

Publish Date: August 26, 2019