Permit Conditions: Limitations and Monitoring

All permits issued by the Wastewater Regulatory Program contain certain permit conditions for the protection of water quality, POTWs, and drinking water standards based on the method of disposal, such as discharge to a water of the State (NPDES), discharge to a POTW (Pretreatment), or land application (LAS), respectively.

These conditions included in wastewater permits are generally based upon applicable technology and water quality standards. Some sites, however, may have additional site specific criteria that require the implementation of special conditions. These conditions are developed following the application submittal and during the permitting process.   

Limitations and/or monitoring requirements may include, but are not limited to, the following:

All effluent conditions include a defined monitoring frequency and sampling location. Monitoring frequencies vary depending on facility specific operations. Permittees should review their permits carefully as different conditions may require varying frequencies. Depending on the site, sampling locations may include, but are not limited to, the following:

• Influent
• Effluent
• Internal Points
• Surface Water
• Groundwater
• Soil

In some instances, a facility may be granted additional time to meet a permit limit. More information on compliance schedules may be found below.

Technology Based Effluent Limitations

Technology-based effluent limitations standardize a minimum level of effluent quality that is attainable using demonstrated technologies for reducing discharges of pollutants into the waters of the United States. TBELs are developed independently of the potential impact of a discharge on the receiving water, which is addressed through water quality standards and water quality-based effluent limitations.

Water Quality and Drinking Water Standards

NPDES Permits

Water quality based limitations (WQBLs) are imposed in wastewater permits when it is determined that technology based limitations are not sufficient to protect water quality (40 CFR 125.3). These limitations are based on state and federal water quality standards and the assimilative capacity of the receiving stream.

In addition to surface water modeling, EPD has developed a number of permitting strategies and reasonable potential analysis procedures to aid in the determination of monitoring requirements and limitations for certain parameters. These strategies and procedures may be found here.

Permit holders should also note whether or not the receiving stream has been listed as supporting or not supporting its designated use (fishing, recreation, or drinking water) on the 303(d) List and whether or not a Total Maximum Daily Load (TMDL) has been completed for the receiving stream. These designations may affect the monitoring requirements or limitations included within a facility’s permit. For more information on the 303(d) List and/or TMDLs, please visit the Assessment and/or Water Quality Modeling pages, respectively.  

Additional information on how limitations are developed may be found with our permit condition guidance documents here.

LAS Permits

Downgradient groundwater wells may be specifically monitored for the protection of drinking water sources. Limitations may also be employed to ensure that all drinking water standards are met downgradient of the application site.

Pretreatment Permits

Limitations based on water quality may be included to ensure that the effluent will not cause the receiving POTW to violate their own limits or pass through the receiving POTW and violate water quality standards in the ultimate receiving stream.

Compliance Schedules

A schedule may be added to allow a reasonable period of time for a facility to achieve compliance. The schedule outlined in the permit may require periodic progress reports, design development reports, and/or plans and specifications be submitted to EPD after the effective date until compliance is achieved. Comments on the conditions of the permit must be made prior to or during the public notice period, if a facility does not believe that they can meet a new water quality based limitation.

Please note that compliance schedules may only be included for water quality based limitations in compliance with the Clean Water Act and applicable regulations. The deadlines for achieving compliance with the federally promulgated effluent limit guidelines established under the Act have already passed and thus must be met upon the effective date of the permit.