Instructions for Outside Washing


The guidelines below outline proper disposal of wastewater generated from activities associated with outside washing of property and vehicles.  This includes, but is not limited to, the cosmetic cleaning of streets, parking lots, sidewalks, building walls and roofs, and washing of vehicles.  All discharges to a City of Mesquite drainage or sewer system must comply with the applicable requirements as set forth in the City of Mesquite code of ordinances.

Disposal of anything other than stormwater into the storm drainage system is unlawful.  The only exception is if  your wastewater does not carry pollutants into the storm drainage system.  Proof, such as analytical results of proposed/ past discharges, may be required to establish that the subject discharge(s) do/did not contain pollutants.

Conversely, it is also unlawful to discharge stormwater to the sanitary sewage system.  Further, the pollutants contained in wastewater discharged to the sanitary sewer system may not exceed levels set froth by Ordinance 2823.  Sanitary sewer discharges of certain washing processes may be subject to other Federal or local regulations and may require approval prior to discharge.  Contact the Stormwater Specialist at 972-329-8537 if you are unsure or if your discharge will be subject to these additional regulations.

General Surface Cleaning and Pressure Washing 

• Use dry cleanup methods prior to any pressure washing. Use absorbents (kitty litter, rags, sand, etc.) to clean up spills, sweeping, vacuuming, and scrapping off dried debris. The waste material should be disposed of as solid waste.
• Solids should be removed from the area prior to pressure washing and a filter bag or similar filtration device should be used to remove suspended solids from the wastewater.
• Discharge of any wash water from mobile power washers, directly or via a storm sewer, to surface water in the state* is not authorized under any stormwater permit, either industrial or municipal, and is a violation of the Texas Surface Water Quality Standards.
• If you do not use any chemicals or detergents and are only cleaning surfaces of ambient dust, then you may direct the wastewater to nearby landscaping or vegetated area or contain it onsite and allow it to evaporate. When discharging wash water to landscaping, make sure water is absorbed into vegetated or permeable surfaces (gravel, porous pavement) and does not cause erosion or run off into a storm drain or paved area.
•  All other wash water must be captured for proper disposal.
•  Pressure wash with minimal water.
•  A visible sheen must not be evident in the discharge. Use an absorbent pad or boom to eliminate any oil from the discharge.
•  Do not pressure wash an entire building. Spot clean, steam clean, or scrape dirty areas rather than pressure washing the entire structure.

Storm Drain Protection

•  Prior to pressure washing, identify where all storm drains are located; wash water must not be allowed to flow down gutters or enter storm drains.
•  Block or cover all storm drains with booms and weighted storm drain covers before pressure washing.
•  Determine where water will pool for collection. Use a wet vac to vacuum up the wastewater or 
allow water to evaporate.

Disposal of Wash Water

•   Use a wet vacuum to collect water for disposal to the sanitary sewer.
•   Once water is collected, dispose of it properly. Collected wash water may be disposed of into a sanitary sewer drain at the job site or at the contractor’s place of business.

Car wash Fundraisers 

Before a fund raising car wash or volunteer car wash event is allowed in the City, it is best to check on the City's current water restrictions.  Year-round conservation measures require a hose shut-off nozzle for vehicle washing and prohibit runoff from paved areas. At times, additional water restrictions may be implemented and vigorously enforced due to drought or water shortages.

How can a car wash pollute our creeks?

A car wash is a great way to have fun while raising funds for your school or community group.  But did you know that if soap water enters the storm drain system it will flow directly to the nearest creek?  Soap (even if it is biodegradable) is a pollutant that can be harmful to fish and other aquatic life that depend on clean water for their survival.  Car wash water in addition to the soap used can carry pollutants such as dirt, oil, and other automotive fluids that may go directly into our creeks.  It may be best to have a car wash located over a grassy surface,  instead of a parking lot that has an impervious surface.

Once the car wash is over can soap residue harm creeks?

Yes, rain can wash the soap into the storm drain system where it can then pollute creeks.  If the car wash area is not on a grassed surface, it is a good idea at the end of the car wash, while the storm drain protection is still in place, to thoroughly rinse down the wash area and properly dispose of the rinse water.

Is it possible to host a car wash that doesn't pollute creeks?

Yes, you can have to select a site where the wash water can be disposed of without it entering a storm drain.  The City of Mesquite has personnel that can help you determine if the site is appropriate and offer suggestions on how to dispose of the water.

How do I keep car wash water from entering the storm drain system?

It is important to select a site where the wash water can be disposed of without it entering a storm drain.  If the car wash area is not on a grassed surface, it is a good idea at the end of the car wash, while the storm drain protection is still in place, to thoroughly rinse down the wash area and properly dispose of the rinse water. There are several ways you can do this:.
  • Wash the cars in a place where the natural drainage pattern will route wash water into a vegetated area such as a lawn or vacant lot.  Be sure to have the owner's permission if wash water is draining onto a neighboring property.  You might be able to use sand bags, rolled towels, hoses, or other materials to divert the surface runoff to the vegetated area.  
  • Another way is to seal off the storm drain, collect the water, and use a small sump pump to pump the water to either a vegetated area or into a clean out opening to the sanitary sewer.
Call the Storm Water Specialist for assistance at 972-329-8537 or Environmental Code at 972-329-8704.