Unusual Discharge Request (UDR)

Any short-term one-time discharge to the sewer system requires approval through MSD’s Unusual Discharge Request (UDR) program.

The UDR program gives MSD control over the type and characteristics of the wastewater being discharged and allows us to ensure that contaminants that might cause problems at the treatment plants are not allowed to enter the sewer system. UDR wastewater is normally discharged to MSD’s collection system through the discharger’s Property Service Connection (PSC) though alternate discharge points may be allowed if necessary. The approval process is described below.

Initial Request:  Companies that need to dispose of a batch of wastewater not covered by any other MSD discharge permit should direct a request to UDRApplications@louisvillemsd.org.

Parameters for Analysis:  MSD will determine what parameters need to be analyzed based on the quantity and type of material to be discharged and the treatment center to which it will flow. Wastewater for all Underground Storage Tank (UST) excavations must, at a minimum, be analyzed on the following parameters:

  • Benzene, Toluene, Ethyl Benzene, Xylene (BTEX)
  • Total Petroleum Hydrocarbon (TPH or Oil & Grease Hydrocarbon)
  • Polycyclic Aromatic Hydrocarbon (PAH)
  • Total Lead
  • Closed Cup Flashpoint

Sample Collection:   Typically, at least one representative sample must be collected of the wastewater that is proposed for discharge.  "Representative" means that the collected sample has the same characteristics as the rest of the wastewater.  Samples must be collected and analyzed in accordance with 40 CFR 136 for the parameters specified by MSD.  Other requirements can be included as part of the UDR approval.

Certain activities require payment of review and inspection services. MSD encourages the use of its development application eService Portal for payment of charges. Use of this portal will also enable an applicant to get e-mail updates on the status of the application.


For questions regarding eService Portal payment and charges, email UDRApplications@louisvillemsd.org .

For instructions for creating an account or for a one-time payment option, select the following: 
 New Account Guide or Guest Payments Guide.