Texas Onsite - Civil Engineering and Wastewater System Design Experts

The Commercial Process is Vastly Different.

In the State of Texas, there is a "trigger point" in the permit process, as to how a permit is obtained for a wastewater system, be it on onsite system, or central collection system.

If your flows exceed a certain average daily flow limit, you must obtain a permit from the Texas Commission on Environmental Quality.  This process can be quite time consuming.

If your flows fall below this limit (currently 5,000 gpd), you can often (but not always) obtain a permit from your local Regulatory Authority.

It is important to understand that your effluent "strength" may also require you to design and construct a "commercial" system. Any sewage beyond a biochemical oxygen demand of 140 mg/L BOD is considered "high strength", or with other unusual components (such as fats, oils, greases, or unusually high suspended solids). This can actually happen in a residence, too.

With onsite commercial systems it is vitally important to not only address the hydraulic loading of the system (how many gallons per day/week/month/year and any unusual "peak" events), but more importantly the biological loading, in terms of the waste stream being put "down the drain". Different types of commercial establishments generate vastly different sewage strengths, often at different times of the day, and we will help you identify these items for a proper design by a Professional Engineer for your site.

You may be told that there are "charts" from which a cookbook design may be done. This is not true. Each commercial design needs to be site specific, and designed with the specific operating conditions of the site, the ability of the soils on the site to process the mass-loading of the effluent, and the intended use of the system carefully considered. Lack of proper planning and operation often results in costly system failure. If you find someone with an inexpensive "cookbook" design, please be aware that even if you get a permit from your local agency, the issuance of a permit does not guarantee the system will work. The Permit Authority relies upon the designer to properly design the system, and current State Codes are design minimums, only. 

For permits over 5,000 gpd, our firm collects data on actual mass and hydraulic loadings, and sizes a plant, with proper flow equalization, pre-treatment, and clarifiers where they will do the most good, in the most cost-effective manner, in terms of life-cycle.

Additionally, please note that the use of pre-existing small scale aerobic treatment units, that carry a NSF Class I rating, and on a State-approved list, are for Residential Use ONLY. While they may be used in smaller commercial systems, State Law requires you use the services of a Registered Professional Engineer to design such systems, as you are modifying the use for which these units were originally intended. 

Our firm has diverse experience in all sizes of systems. We have been involved with phased systems that exceed several hundred thousand gallons per day.

We recommend that you consult with a Licensed Registered Engineer before you expend any major funds on a property purchase. A little money spent doing a feasibility can save you thousands of dollars later.

There are a variety of cost-effective methods to treat and dispose of effluent.  Let us show you how. Please contact us for our current fee schedule to perform feasibility analysis for your project. Fast track work is available (for performing due diligence during a real estate option period).

Discharge Types

This is one of many questions that must be considered in the design process. In short, do you want to do a direct discharge of your effluent, or do you want to keep all effluent onsite?  We can "run the numbers" on the most cost-effective manner in which to treat - and therefore dispose of - your proposed effluent.