Getting DNR wash water permit coverage in Wisconsin
How does a Wisconsin pressure washing business apply for the DNR low-impact discharge permit?
- Map where each type of job sends its wash water
- Move any hauled or sanitary sewer routes outside the permit
- Certify the narrative discharge screening in the notice
- Write the best management practice plan
- Submit the electronic notice of intent 30 business days early
- Wait for the DNR coverage letter before discharging
- Keep the plan in the truck and the office
- Log inspections at least monthly and train the crew
Decide which jobs need the permit at all
Start with the routes, not the form. List your usual jobs, and for each one write down where the water goes: a storm sewer, the ground, a sanitary sewer or a hauled tank.
Routes to a holding tank that is pumped to a public treatment works, or to a sanitary sewer that reaches a treatment works, are excluded from coverage. Storm sewer and ground routes are the ones the permit governs.
If every job you take can go to a tank or a sanitary sewer, you may not need coverage. If some cannot, plan to apply. The destinations page covers each route.
The permit excludes discharges to a holding tank hauled to a treatment works or to a sanitary sewer that conveys wastewater to a treatment works. — Wisconsin DNR, Low-Impact Discharge general permit WI-0066575-01-0, retrieved 2026-09-29
Write the plan before you file the notice
The best management practice plan goes in with the notice, so write it first. The DNR approves it, and you must then run your operations to match it.
The plan's contents are set out in the permit. They include an inspection program with an example log, an employee training program, a good housekeeping program, a contingency plan, and a recordkeeping and reporting program.
It also describes erosion and sediment control, discharge procedures for groundwater and surface waters, and site maps showing each outfall. For a mobile crew, one plan that covers all discharge types can serve every job.
The BMP plan must include an inspection program, training program, housekeeping program, contingency plan and recordkeeping program. — Wisconsin DNR, Low-Impact Discharge general permit WI-0066575-01-0, retrieved 2026-09-29
Permittees with statewide coverage for temporary discharges may prepare one BMP plan that includes all applicable discharge types. — Wisconsin DNR, Low-Impact Discharge general permit WI-0066575-01-0, retrieved 2026-09-29
File the notice of intent and wait for the letter
Submit a complete notice of intent at least 30 business days before you expect to start discharging. The DNR's general permit page carries the notice, and it is filed electronically.
Attach the discharge screening results and the plan. The department may ask for more if the notice is incomplete, and you must send what it asks for.
Then wait. The applicant must receive a letter granting coverage before discharging to waters of the state, and without that letter you may not discharge.
An applicant may not discharge to waters of the state until it receives the DNR's letter granting coverage. — Wisconsin DNR, Low-Impact Discharge general permit WI-0066575-01-0, retrieved 2026-09-29
The DNR charges no application fee for most wastewater general permits, and notices of intent are submitted electronically. — Wisconsin DNR wastewater general permits page, retrieved 2026-09-29
If the DNR says the discharge is ineligible
The DNR can decide a discharge does not fit this permit but still needs coverage. The permit tells you what to do then.
You apply for and obtain coverage under an individual WPDES permit, or another general permit if one is available, before you discharge. The permit points to the DNR's page on applying for a WPDES permit for that route.
Plan for the time this takes. If a job depends on the discharge, hold it until coverage arrives, or reroute the water to a tank or sanitary sewer in the meantime.
If the DNR finds a discharge ineligible but still needing coverage, the applicant must obtain an individual or other general WPDES permit first. — Wisconsin DNR, Low-Impact Discharge general permit WI-0066575-01-0, retrieved 2026-09-29
Keep the plan alive after approval
Approval is the start of the work. The plan must be kept at the facility, and every office that must hold the general permit also holds it.
Inspection logs run at least monthly. Employees get BMP training tied to their duties. Records include the notice, screening results, inspection reports and training materials, and the DNR can inspect them or ask for them.
Put the reminders on the same calendar as your tax dates. The registration guide covers those, and the checklist turns this into a crew routine.
The permittee must keep a copy of the BMP plan at the facility and make it available for DNR inspection or on request. — Wisconsin DNR, Low-Impact Discharge general permit WI-0066575-01-0, retrieved 2026-09-29
Questions
How long does it take to get coverage?
The permit asks for the notice at least 30 business days before the expected start of discharge. The DNR may ask for more information if the notice is incomplete, which adds time, so file well before your busy season.
Can I apply on paper?
The permit allowed paper notices only until electronic filing was available. The DNR's general permit page now says notices go in electronically, so use the online system and keep the confirmation with your records.
Does one permit cover every county in Wisconsin?
Statewide coverage exists for operations with temporary discharges at multiple locations, so a mobile crew does not reapply for each site. A discharge that hits an excluded water, such as an outstanding resource water, is still outside it.