Surface Water Discharge

The Montana Department of Environmental Quality has the responsibility to protect the public health and the environment by ensuring wastewater is properly handled and treated safely. Whenever a municipality, industry, or other entity wishes to discharge water to a surface water of the state, that entity must first obtain a permit from DEQ. Montana Pollutant Discharge Elimination System (MPDES) permits regulate wastewater discharges by limiting the quantities of pollutants to be discharged. The limits and/or requirements in the permit help ensure compliance with Montana’s Water Quality Standards, State and Federal Regulations, all of which were written to protect public health and the aquatic environment. The series of steps for a particular permit may vary somewhat depending on the size, nature, and complexity of the discharge.

Types of Permits

There are two types of Montana Pollutant Discharge Elimination System permits: Individual and General. An Individual MPDES permit is unique to each facility. The limitations and requirements in an Individual Permit are based on the facility's operations, type and amount of discharge, and the nature of the receiving stream, among other factors. Conversely, some point sources can be grouped under a category of sources that contain very similar or, in many cases, identical effluent limitations and requirements; their contents have been compiled into one permit, known as a General Permit.

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A General Permit is one permit that covers facilities that have similar operations and types of discharge. General Permits are used to cover discharges that will have a minimal effect on the environment. Examples of this category of permit would be wastewater discharges associated with common activities, such as concentrated animal feeding operations and storm water discharges from construction or industrial activity. Written authorization from DEQ is required before an applicant can dishcarge under the General Permit.

The General Permit for Pesticides is the wastewater discharge mechanism for anyone who applies pesticides into or over state surface water. This is not a pesticide permit; rather, it is a wastewater discharge permit under the Montana Pollution Discharge Elimination System (MPDES) program. A completed Notice of Intent is required. Note, in Montana, if an applicant requests coverage for annual pesticide applications in areas greater than annual pesticide use pattern thresholds list in Table 1 of the Pesticide General Permit, they are classified as above-threshold (or Tier II) facilities and are subject to additional requirements, including the development of a Pesticide Discharge Managemement Plan. If application coverage is for less than the acreage thresholds, they are considered Tier I permit holders and subject to universal requirements.

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