Wyoming State Overview

The state of Wyoming and the Wyoming Department of Environmental Quality (WYDEQ) were granted delegated authority by the EPA to administer their own “State-Specific” National Pollutant Discharge Elimination System (NPDES) Permitting Program for wastewater and stormwater discharges associated with construction activity, industrial activity as well as Municipal Separate Storm Sewer System (MS4) activity. Because the EPA and The Clean Water Act (CWA) required a program for addressing the pollution caused by stormwater discharges, the Wyoming Department of Environmental Quality instituted the Wyoming Pollutant Discharge Elimination System (WYPDES) Stormwater Program. The purpose of the Wyoming Pollutant Discharge Elimination System Stormwater Program is to prevent stormwater and wastewater runoff from washing harmful pollutants into all surface waters (streams, rivers, lakes or coastal waters) of the state of Wyoming.

As per the WYDEQ, the “operator,” or “owner” of the project site that will be implementing construction activities (clearing, grading and excavation) and discharging stormwater or wastewater is required to attain general permit coverage through the WYPDES Permitting Program before construction can commence. Depending on the characteristics of the construction project, an owner or operator is required to apply for one of the two following Construction General Permits allowing discharge from his/her construction site to surface waters of the State: 

• General Permit to Discharge Stormwater Associated with Large Construction Activities -  “Large Construction Activities” are defined as a project site that disturbs and/or clears five (5) or more acres of land.

• General Permit to Discharge Stormwater Associated with Small Construction Activities - “Small Construction Activities” are defined as a project site that disturbs less than five (5) acres of land. An operator of a project site must also apply for general permit coverage if his/her site will disturb less than one (1) acre, but is part of a larger common plan of development or sale, that will ultimately disturb one (1) or more acres.

A project site owner or operator can apply for general permit coverage if he/she submits a Notice of Intent (NOI) to the Wyoming Department of Environmental Quality (WYDEQ) for site review and analysis.  The Wyoming Pollutant Discharge Elimination System (WYPDES) Stormwater Program mandates that before a Notice of Intent (NOI) can be submitted, a Storm Water Pollution Prevention Plan (SWPPP) must be developed, prepared and submitted with the NOI application.  The objective of the Storm Water Pollution Prevention Plan (SWPPP) is to: (1) identify pollutants which have potential to leave the construction site in stormwater runoff; and (2) identify erosion and sediment control Best Management Practices (BMPs) which, when implemented, will eliminate or minimize pollutants in runoff and meet the terms and conditions of the WYPDES General Permit. After the SWPPP has been developed, the owner or operator of the project site can then submit their Notice of Intent (NOI) for review.