Building a Private WWTP in Texas: What Developers Need to Know Before They Commit

Before you commit to a private WWTP in Texas, you need four answers: whether TCEQ will accept a new plant when another sewer system is nearby, where the treated water will go, how much flow the plant must carry in phase one and at buildout, and who will own and run it for decades. The permit, site plan and pro forma follow from those answers.

When does a private WWTP make sense for a Texas development?

When the site has no practical sewer connection, or the nearest system cannot or will not take your flow. Where a connection is practical, it usually wins.

Connecting hands treatment, permits and operators to a utility. Building keeps all three with you. Make the call with real costs from a site feasibility study: extending a line and buying capacity, against permitting, building, operating and expanding a plant.

Will TCEQ let you build a plant if a city sewer is nearby?

Possibly, but you have to show your work. TCEQ checks for regional options before it issues a new domestic wastewater permit.

TCEQ's regionalization policy page cites Texas Water Code §26.0282, which lets TCEQ deny or alter a discharge permit based on need and the availability of regional systems. The Domestic Technical Report, Form TCEQ-10054, on TCEQ's application steps page, asks whether any of the service area is inside a city or another utility's certificate of convenience and necessity (CCN) area, and whether any permitted plant or collection system sits within three miles. Inside a city, attach the city's letters. Inside another CCN, attach a cost analysis of connecting versus building. For each system within three miles, attach a list and map, proof you mailed a service request, and the replies. If the city or a nearby system agrees to serve, add the same cost analysis.

A nearby system is not an automatic denial. TCEQ may approve where nothing is within three miles, service was refused, costs or affordable rates justify an exception, or the applicant holds a CCN for the area.

Which TCEQ permit does a private WWTP need?

That depends on where the treated water goes. Pick the disposal path first; it sets the permit, the effluent limits and the land you give up.

TCEQ's domestic wastewater permits page splits it two ways. A Texas Pollutant Discharge Elimination System (TPDES) permit covers a discharge into water in the state. A Texas Land Application Permit (TLAP) covers disposal by surface irrigation, evaporation, drainfields or subsurface application. For a discharge, TCEQ's public guide to municipal wastewater permits says the agency studies the receiving water and how much added load it can tolerate. For land application, the technical report asks for soil maps and analyses of the disposal site instead.

Reuse is the third piece. Under 30 TAC Chapter 210, a provider needs TCEQ's written approval before supplying reclaimed water to another user (§210.4), and reclaimed water discharged to water in the state still needs a permit (§210.5). Plan storage or a permitted outlet for the wet weeks when nobody wants the water. Industrial reclaimed water follows Subchapter E, the path behind a 210E authorization.

How should you size the plant, and can you build it in phases?

Permit for buildout and build in phases. TCEQ's application asks for phases, and its rules say when to start the next one.

Under 30 TAC §217.32, design flow starts from the per capita flows in Table B.1 times the people served, multiplied by at least 1.5 below 1.0 MGD. Without site-specific data, peak flow is at least 4.0 times design flow. Actual organic loading data, where it exists, comes first.

The technical report asks for an Interim I, Interim II and Final phase, each with its own design flow, peak flow and start dates, and a justification for every phase not yet permitted. Once the plant runs, 30 TAC §305.126 sets the clock: at 75% of permitted flow for three consecutive months, start engineering and financial planning for expansion; at 90% for three months, obtain TCEQ authorization to build. Design the next train before you hit 75%.

Where can the plant sit on your site?

Out of the 100-year floodplain or protected from it, with an odor buffer of at least 150 feet to the property line for most units, or an approved alternative.

30 TAC §309.13 bars a plant unit from the 100-year floodplain unless it is protected from inundation and damage. For odor, it allows three options: keep units 150 feet from the property line (500 feet for lagoons with anaerobic zones), submit a sealed nuisance odor prevention report, or show legal restrictions that prohibit homes in the part of the buffer you do not own. On a subdivision, that buffer is land you cannot sell as homesites. Put the plant, buffer and outfall or irrigation fields on the first concept plan.

Who will own and operate the plant?

Decide before you file. The permit holder carries the operator, monitoring and renewal duties for as long as the plant runs.

Under 30 TAC §30.350, every permit holder must employ or contract with licensed operators or a registered operations company. The chief operator's license must match or exceed the facility's category, and an operator at that level must run the plant at least five days a week and be reachable seven.

Selling sewer service adds a layer. Under 16 TAC §24.225, a utility may not provide retail sewer service to the public without a CCN from the Public Utility Commission of Texas, and a district cannot serve inside another utility's certificated area without consent or its own CCN. For developers and builders, the usual choices are to own the plant and contract the operation, form or join a district, or convey the plant to a utility.

How long does TCEQ permitting take?

Longer than most pro formas assume, and no one can promise a date. The steps page says to submit a complete application at least 330 days before the proposed discharge begins.

Administrative review can bring a notice of deficiency with a deadline. Then come two published notices, a comment period that typically ends 30 days after the second, possible public meetings and contested case hearing requests, per the public guide. For a new facility, TCEQ highly recommends contacting its permitting staff well before you apply. Do it.

Are you ready to commit to a private WWTP?

You are ready to start design when you can answer yes to all six.

1. Have you asked the city or CCN holder covering the site, and every permitted system within three miles, for service in writing?
2. Do you have a cost comparison of connecting versus building, running and expanding a plant?
3. Have you chosen a disposal path and checked the receiving stream or the soils?
4. Is the design flow built from Table B.1 or real data, with phases that match lot releases?
5. Does the plant site clear the floodplain and hold the buffer or an approved alternative?
6. Do you know who will hold the permit, any CCN, and the operator contract?

Six yeses mean the site is ready for design; any no comes first.

Questions for your engineer: What does the three-mile map show? Which disposal path carries the least permit risk here? What lot count triggers phase two?

A note on limits: this is general education from TCEQ and Public Utility Commission rules and guidance as published in October 2026. Your permit and site conditions govern, and no article can predict a review outcome or a schedule.

Frequently asked questions

What is a private WWTP?

A wastewater treatment plant owned by a developer, private utility or business instead of a city. It needs the same TCEQ authorization as any plant that discharges or land-applies treated domestic wastewater.

Does TCEQ approve the design of a private WWTP?

The design must meet 30 TAC Chapter 217 and the permit's effluent limits. Under 30 TAC §217.6, the owner sends TCEQ a summary transmittal letter sealed by the design engineer. If TCEQ does not say in writing within 30 business days that it will review the plans, the project is conditionally approved.

I'm developing a 400-lot subdivision in a Texas city's ETJ and the city's sewer line is two miles away. Do I have to connect instead of building my own plant?

Not automatically. Ask that system for service in writing and include its answer with your application. If it agrees to serve, you attach a cost comparison of connecting versus building, and that comparison has to hold up.

I'm a Texas homebuilder planning to hire an operations company to run our package plant after startup. What does TCEQ expect from the operator?

A chief operator licensed at or above the plant's category. The chief operator, or another operator licensed at that level, must run the plant at least five days a week and be reachable seven. The permit holder must employ or contract licensed operators or a registered operations company, so write those duties into the contract before startup.

Related resources

• How to Evaluate Wastewater Utility Options Before You Close on Land (Connect, Build, or Wait)
• Private Wastewater Treatment Plants in Texas: When Developers Need Their Own TPDES Permit
• Flow Rate Projections: How to Size a Wastewater Treatment Plant for Your Development Without Over-Building
• Land Application Permits for Treated Wastewater: A Texas Developer’s Guide

Weighing a private plant for a Texas development?

We map the three-mile review, compare connecting with building, and size the plant phases around your lot plan before you commit to a permit path.

Talk to Modern Engineering Solutions about your site, or call (214) 833-6748.