What Southfield's rules say about wash water.
Michigan does not license this trade, and the city's published permits include nothing for it. What the city does regulate is where the water ends up — and that rule is short, specific, and worth knowing before you hire anyone.
A referral service for Southfield homeowners. An automated assistant answers; calls are recorded.
Typical cost: house wash $170 – $360, most about $265; roof soft wash $250 – $600 — national ranges (HomeGuide’s national chart, June 2025)
- Cost to call
- Nothing
- Answered by
- Automated assistant
- Hours
- Any hour
The rule
Southfield's own rule bars putting anything but stormwater into the storm drain system. The list of things it lets off is short, and the only washing on it is a homeowner washing their own car — a paid wash is not on that list (the city's own rule).
The same rule defines an illicit connection to include anything that lets sewage, process wastewater or wash water reach the storm drain, and it applies to all water generated on any land in the city, developed or not (the rule).
In practice this is not a hard rule to meet. Sweep the surface first, and let the rinse water run onto grass or planting beds where the ground can filter it — which is the same thing the region's advice tells a homeowner to do with a car (what the region tells homeowners).
Why it matters here
In Southfield the storm drain and the sewer are two different systems. A sanitary sewer takes what goes down the sinks and toilets to a treatment plant; the storm drains along the curbs do not go to a treatment facility at all (the city's own explainer).
About 90% of the city drains to the Rouge River, and the rest drains toward the Clinton — so whatever goes into the drain at the curb ends up in one of them (the city's own explainer).
The city's storm water office takes questions about all of this on 248-796-4806 (the city's storm water page).
Reporting something going into a drain
The county runs a 24-hour line for this — 248-858-0931 — for pollution in a storm drain, suspicious dumping, suspicious discharges from a pipe, or sewage on the ground. It is not a way to reach a contractor and we have no part in it (the county's page).
What the page asks you to have ready, in its order:
- Your name and phone number — you can stay anonymous if you prefer.
- Where it came from, and what was spilled.
- How much.
- Which lake, creek or stream it reached, if you know.
- When it happened, and the nearest cross roads.
Licensing and permits
Southfield. The city's published permits are for building, engineering, right of way, soil erosion and utilities, and its building department handles new construction, renovation and expansion. None of that covers cleaning, and the city's list of what a new business must do names no cleaning license (the permits the city publishes · the building department · what the city tells a new business). The city does not say outright that none is needed, so ask the building department if you want to be sure.
Michigan. The state's residential contractor license covers twelve building crafts — carpentry, concrete, pools, basement waterproofing, excavation, insulation, masonry, roofing, siding and gutters, storm sash, tile and marble, and house wrecking — and exterior cleaning is not one of them, so there is no state license for a wash to check (the twelve crafts · the state's page for residential builders).
What to ask for instead. Proof of insurance, and the price in writing. And if the job turns into siding, gutter or roof repair, that work does need a licensed contractor — you can check any license yourself at the state license lookup.
One question tells you what kind of contractor you have.
Southfield's rule keeps wash water out of the storm drain and exempts only a homeowner washing their own car, so a paid wash has to send its rinse water somewhere else. the city's own rule
Ask where the rinse water goes. Grass or planting beds is the right answer; the drain at the curb is not.
Questions
Do I need a permit to have my house washed?
- Nothing in the city's published permits or its guidance for new businesses requires one for exterior cleaning (the permits the city publishes · what the city tells a new business). The city does not say outright that none is needed; the building department's line is 248-796-4100 if you want to ask (the building department).
Can a contractor just rinse into the street?
- The rule is written against exactly that: anything but stormwater reaching the storm drain system, with only a homeowner washing their own car let off (the rule). Ask where the rinse water goes before the work starts.
Is the storm drain the same as the sewer?
- No — they are two separate systems here, and what goes into a storm drain is not treated (the city's own explainer). That is the whole reason the rule exists.
How do I check a license if the job becomes a repair?
- Search the contractor's name or license number yourself at the state license lookup. We do not check it for you and we do not vouch for anyone's license.