The Department of Environmental Quality/Water Quality Division (DEQ) has conducted a review of the proposed Lagoon Improvements, Phase 2 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 proposed project will include improvements to the existing lagoon cell(s) in order to meet water quality compliance requirements currently not being met by the Town of Encampment. Specifically, periodic discharge permit limits for BOD and pH have been out of compliance due to inadequate treatment. The upgrades to the treatment process under this phase of the project will include installation of a submerged air diffusion system to improve aeration and denitrification activity as well as the installation of baffling within lagoon cell one to reduce short-circuiting and improve treatment. A new blower building will be installed adjacent to lagoon cell one to house the submerged air diffusion compressors and controls. New perimeter fencing will also be installed. The limits of construction for this project are completely within the boundary of the existing lagoon facility.

The estimated cost for the Lagoon Improvements, Phase 2 Project is $1,560,200. The Town of Encampment has requested a Wyoming Clean Water State Revolving Loan Fund in the amount of $500,000. Principal forgiveness in the amount of $375,000 (75%) has been requested. Loan terms will be 1.5% interest rate and the term of the loan will be 20 years. The Town of Encampment has allocated $1,060,200 of Specific Purpose Tax funds to be used to fund the project. User rate fees will not be increased as a result of this project.

The Town of Encampment 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. No significant environmental impacts that require mitigation have been identified.

DEQ is granting an exclusion because the project includes modifications to an existing system and is being constructed in previously disturbed ground, specifically ground previously disturbed by the construction of the existing lagoon cells, sewer lines, underdrains, and access roads. 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 Encampment, Carbon County, Wyoming.