Most conversations about apartment exterior cleaning are about appearance, turnover and leasing photos. Those matter. But the item that can actually generate a citation is not on that list, and it has nothing to do with how the property looks when the crew leaves, it is where the water went.
A pressure washing job on a breezeway, a dumpster pad or a parking deck produces hundreds of gallons of water carrying detergent, oil, algae and whatever else was on the surface. If that runs down the nearest inlet, it has entered the municipal storm sewer, and it is not stormwater. That is the compliance exposure most managers do not know they are carrying, usually because the contractor never mentioned it. What follows is that issue, and the handful of others worth having on a Houston multifamily maintenance calendar.
Wash water into a storm drain is a named offense
The federal framework is straightforward. Under the EPA’s stormwater rules, cities operating a municipal separate storm sewer system are required to effectively prohibit, through an ordinance or other regulatory mechanism, non-stormwater discharges into the system, and to implement enforcement procedures and actions (US EPA). Every city with a storm sewer permit has one of these ordinances because it is a condition of the permit.
Houston’s sits in Chapter 47 of the City Code. The city’s own enforcement correspondence quotes it: a person commits an offense if the person threatens to introduce, introduces or causes to be introduced into the MS4 any discharge that is not composed entirely of storm water (City of Houston, Code section 47-741).
The obvious question is whether washing counts. At the state level, TCEQ’s general permit lists the categories of non-stormwater that are allowed into a storm sewer, and the list is specific. Individual residential vehicle washing is on it. So is street wash water, excluding street sweeper waste water. Commercial building washing and pavement washing at an apartment complex are not (TCEQ, TPDES General Permit TXR040000). Houston operates under its own large-system permit rather than that general permit, so treat the list as evidence of how Texas classifies these discharges rather than as the rule Houston itself is issued under. The classification is the point: your wash water is not on anybody’s allowed list.
I am not going to quote you a fine figure, because I could not verify one specific to Chapter 47 and I am not going to invent it. The exposure is real without a number attached, and the fix is cheap.
The question that transfers the risk
Ask the contractor, before the job, how they capture and dispose of the water.
There is a published answer to compare theirs against. The EPA’s best practice guidance for washing operations describes it in one sentence: for a small job, they can use a bermed wash area and capture the wash water with a wet/dry vacuum for discharge to a sanitary sewer (US EPA). Berm the area, recover the water, send it to sanitary sewer rather than storm. On larger areas the equipment scales up to vacuum recovery units and filtration, but the principle does not change.
A contractor who has a clear answer to that question has thought about it. One who looks blank is planning to let it run, and the property owner is the one whose name is on the site. Our own commercial pressure washing work at multifamily sites is scoped around containment and recovery from the start, because retrofitting it halfway through a breezeway job does not work.
Dumpster pads deserve a specific mention. They are the highest-load surface on most complexes, the water coming off them is the dirtiest on the property, and they usually sit close to an inlet. If one area on the site gets containment, make it that one.
It is worth getting this into the scope of work in writing rather than leaving it as a verbal assurance. A line in the contract specifying that wash water will be contained and disposed of to sanitary sewer, and that the contractor is responsible for compliance with local discharge rules, costs nothing to add at bid stage. It also filters your bidders. A price that comes in well under the others is often a price that assumes the water runs off site, and the difference between those two numbers is the cost of the equipment and the labour to recover several hundred gallons.
The same applies to in-house work. If your maintenance team owns a pressure washer and handles breezeways between vendor visits, the discharge rule does not distinguish between their water and a contractor’s. Whoever holds the wand, the property is the site of the discharge.
Houston’s routine multifamily inspection looks at the outside
This is the fact I most often find managers do not know. The City of Houston’s multifamily habitability program, presented to its Regulation and Neighborhood Affairs Committee, describes the routine inspection as an exterior inspection only, running across roughly 4,500 complexes over a four-year cycle for buildings with three or more units (City of Houston).
The city’s programmatic look at your property is at exactly the surfaces this article is about. Building exterior condition, stairways, balconies and railings, walkways and exterior lighting are the sort of items on the list. None of that makes cleaning a legal requirement, and I am not suggesting it does. It does mean the visible condition of your exterior is the version of your property the city sees on a scheduled basis, which is a reasonable thing to plan maintenance around.
Note also that Houston has been actively expanding this program, and draft ordinance language moved through council committees during 2026. If you are budgeting against it, confirm the current requirements with the Houston Permitting Center rather than relying on what was true last year.
Registration is free, mandatory, and easy to let lapse
While you are checking, check the registration. The Houston Permitting Center states that registration is free and required by Chapter 10 of the City of Houston Code of Ordinances, and that the program covers multi-tenant properties of three or more units (Houston Permitting Center).
Free and mandatory is an easy combination to get wrong, particularly after an ownership change or a management transition, where the registration was somebody’s job at a company that no longer holds the contract.
One caveat that matters a great deal in this region. A large share of the Houston-area apartment stock sits outside city limits, in unincorporated Harris County or in Katy, Sugar Land, Pearland and the other surrounding municipalities. Houston’s Chapter 10 registration and its habitability program do not automatically follow you there. Check which jurisdiction each property is actually in before applying any of this to a portfolio.
Breezeways and stairs are an accessible route, not a cosmetic surface
The framing I find most useful for walkway cleaning is not slip-and-fall liability, which varies too much to generalise about and is a question for your counsel. It is maintenance of a feature that is required to work.
Federal regulation puts an ongoing duty on covered facilities: a public accommodation shall maintain in operable working condition those features of facilities and equipment that are required to be readily accessible to and usable by persons with disabilities (28 CFR 36.211). Whether and how that applies to a given complex depends on the property, its construction date and how the leasing office is used, so this is one to run past your attorney rather than assume. The underlying idea holds regardless: an accessible route that has been built correctly and then allowed to become slick with algae is not doing the job it was built for.
For a benchmark on what “slip resistant” means in practice, the tile industry standard is a wet dynamic coefficient of friction of at least 0.42 for level floors expected to be walked on when wet. The standards body attaches an important limit to it, saying the measured value shall not be the only factor in determining the appropriateness of a hard surface flooring material for a particular application (Tile Council of North America, ANSI A326.3). It is a specification for selecting flooring, not a pass-fail test you can apply to an existing wet breezeway, and nobody should tell you your walkway is required to hit 0.42. Use it as the standard of care worth aiming at. In practice that means keeping the biological growth off, keeping the surface texture rather than polishing it, and not sealing a walkway with a high-gloss product.
The same logic applies to parking areas and drive lanes, where our driveway and pavement cleaning is usually scheduled alongside the walkway work so the containment setup only has to happen once.
Mold: the Texas line is 25 contiguous square feet
Texas regulates mold assessment and remediation through the Department of Licensing and Regulation, and the threshold is specific. Small areas of mold growth, meaning less than 25 contiguous square feet, can be cleaned or removed by an owner or by maintenance staff (TDLR). At or above 25 contiguous square feet, licensing and notification requirements engage.
There is an exemption in the rules, and this is where managers get caught out. It applies to buildings containing fewer than 10 rental units. Most apartment complexes are well above that, which means the exemption does not cover you.
Two things worth being clear about. Being under the threshold means staff may handle the cleaning. It does not mean the moisture source behind it is acceptable, and it is the moisture source that determines whether it comes back. And the Texas 25 square foot figure is a licensing trigger, not the same as any EPA guidance figure you may have seen quoted for indoor cleanup. They are different thresholds serving different purposes.
Underneath all of this sits the landlord’s repair duty. Texas law requires a landlord to repair conditions that materially affect the physical health or safety of an ordinary tenant, and the state’s own plain-language guidance lists mold among the examples (Texas State Law Library). Chronic exterior moisture, blocked drainage against a wall and standing water on a walkway are all upstream of that.
Building it into a calendar
The practical version for a Houston property is a short list. Confirm registration and jurisdiction once a year. Put dumpster pads and trash enclosures on the most frequent cycle, with containment. Get breezeways and stairs done before the growth is established rather than after somebody complains. Handle the building exteriors on a longer cycle timed around hurricane season rather than during it. And on every job, ask the same question first: where is the water going?
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References
- US EPA, Illicit Discharge Detection and Elimination Minimum Control Measure (Stormwater Phase II Final Rule Fact Sheet 2.5), https://www.epa.gov/system/files/documents/2023-09/EPA-Stormwater-Phase-II-Final-Rule-Factsheet-2.5-IDDE.pdf
- City of Houston, enforcement correspondence citing Code Chapter 47, Article XII, Division 5, Section 47-741, Discharge to MS4 prohibited, https://www.houstontx.gov/council/e/perry-woodridge/Cease-Desist-Figure-Four-Partners-Department-Letterhead.pdf
- Texas Commission on Environmental Quality, TPDES General Permit TXR040000 (Small MS4 General Permit), https://www.tceq.texas.gov/downloads/permitting/stormwater/general/ms4/txr040000-issued-permit.pdf
- US EPA, Stormwater Best Management Practice: Municipal Vehicle and Equipment Washing (EPA-832-F-21-032), https://www.epa.gov/system/files/documents/2021-11/bmp-municipal-vehicle-and-equipment-washing.pdf
- City of Houston, Multifamily Habitability, Regulation and Neighborhood Affairs Committee, https://www.houstontx.gov/council/committees/rna/20211012/multifamily-habitability.pdf
- Houston Permitting Center, Multi-Family Habitability Inspections, https://www.houstonpermittingcenter.org/building-code-enforcement/multi-family-habitability-inspections
- eCFR, 28 CFR 36.211, Maintenance of accessible features, https://www.ecfr.gov/current/title-28/chapter-I/part-36/subpart-C/section-36.211
- Tile Council of North America, Dynamic Coefficient of Friction Frequently Asked Questions (ANSI A326.3), https://tcnatile.com/dynamic-coefficient-of-friction-frequently-asked-questions/
- Texas Department of Licensing and Regulation, Mold Assessors and Remediators FAQs, https://www.tdlr.texas.gov/mld/mldfaq.htm
- Texas State Law Library, Does my landlord have to make repairs?, https://www.sll.texas.gov/faqs/landlord-duty-to-repair/
