Discharges of Filter Backwash and Sedimentation Basin Washout from Water Treatment Plants
***Important Update September 2025***
Permit Issued: September 1, 2025
Permit Effective: September 1, 2025
To apply for a new permit, please go to MyTDEC Forms.
If you have coverage under the WTP-GP currently, but no longer need it, please submit the appropriate documentation (Notice of Termination Form) immediately.
Facilities covered by the WTP-GP can confirm their status by going to the TDEC Permit DataViewer, enter their site's address or the permit tracking number into the search bar, and drill down to the particular record. On that web page, you will see all relevant facility information, including current effective and expiration date.
Any individual who discharges filter backwash and sedimentation basin washout from water treatment plants to the waters of Tennessee must obtain an NPDES permit for such discharge. The most common way to obtain coverage is the WTP (TNG640000), which is available to almost any water treatment plant, but there is also an option of obtaining an individual permit.
A completed Notice of Intent (NOI). This form includes but is not limited to name, mailing address, existing NPDES permit number and location of the facility; name of the owner/operator, mailing address, contact person and phone number; name and location, receiving waters; description of the plant and a list of any additives used in the treatment process; design capacity, the details of the sedimentation basins; the source of raw water; the number of filters that are backwashed, the frequency and volume of backwashes and sedimentation basin washouts; a description of how sludge is disposed; type of treatment provided for backwash and sedimentation basin washwaters and the design capacity of the system.
A map for the facility showing the facility boundaries and the discharge point.
Existing permitted facilities must submit NOI no later than October 1, 2025.
New facilities without WTP coverage should submit NOI at least 30 calendar days prior to commencing discharge.
New owner/operators should submit an NOI at least five days prior to the operator change.
NOI modifications (regarding substantive changes at an already permitted facility) should be submitted as soon as possible but no later than 30 days after the change occurs.
If the applicant misses the deadline to submit NOI, the applicant is not precluded from doing it at a later date. However, filter backwash and sedimentation basin washout discharges are not authorized until they are covered by this or a different NPDES permit. Unauthorized filter backwash and sedimentation basin washout discharges could be subject to an enforcement action.
MyTDEC Forms User Guides
NetDMR Monitoring Report Resources
The division will review each NOI for completeness and accuracy. Within 30 days of receipt of a complete and accurate NOI, the division will transmit to the permittee a notice of coverage (NOC) under this permit, which shall specify the effective date of coverage under the permit. The term of coverage is valid through the expiration date of this general permit. If the division has not been able to transmit an NOC to a permittee within 30 days of receipt of the NOI, discharges are authorized under this permit if the NOI has been assigned a valid NPDES general permit tracking number and the permittee has been informed of this tracking number.
- Permit Application Fee: none
- Annual Permit Fee: $350
A permittee who has submitted an NOI and received permit coverage has the duty to comply with all provisions of the general permit and applicable rules and regulations. If the applicant objects to the Division’s determination they may request that the Division reassess their decisions. This request must be made within 15 days of the transmittal letter. Coverage under the NPDES general permit does not relieve the permittee of the responsibility for damages to surface or ground water. The permittee must notify the Division as soon as possible of planned alteration or additions to the permitted facility or of any change in mailing address. The permittee is responsible for monitoring discharge, reporting data, keeping records, and placing signs at discharge outfalls as detailed in the general permit. If the facility experiences any emergency that could impact the waters of the state, they must notify the Division as detailed in the general permit.
The Division has the right to revoke, suspend, or deny the issuance of a permit to any applicant who violates the state statutes, departmental regulations, or terms of the general permit. The Division has the right to inspect the site, monitoring equipment, and associated records at reasonable times. They also have the right to sample any discharge. Any person who violates or fails to comply with the state statutes, rules, or regulations may be subject to criminal and/or civil penalties.
Applicants may obtain applications and assistance from the Division of Water Resources Central Office or any TDEC Environmental Field Office, or use the form above.