Hydrostatic Testing Records and the TCEQ Audit Trail: What Contractors Need Before an Inspector Shows Up

What records does TXG670000 actually require?

Monitoring records and anything tied to your authorization. Part IV.7.h of TPDES General Permit TXG670000 lists what records of monitoring activities shall include:

1. the date, time and place of the sample or measurement;
2. the identity of the person who collected it;
3. the date and time of laboratory analysis;
4. the identity of the person and laboratory that did the analysis;
5. the technique or method of analysis;
6. the results; and
7. quality assurance and quality control records.

Part IV.9 requires keeping copies of all records the permit requires, including monitoring records and records related to the application or any certification, for three years from the date of the record. The Executive Director can extend that period. The records stay at the facility or readily available for TCEQ review.

Which notices belong in the file?

The ones the permit makes you send before you open a valve. These are easy to miss because they happen days before the test:

• TCEQ regional office: Part III, Section B.13 requires written notice to the appropriate TCEQ regional office at least 48 hours before the discharge starts.
• MS4 operator: under Part III, Section B.14, a discharge that originates inside a municipal separate storm sewer system needs written notice to that operator at least 48 hours ahead.
• NOI and acknowledgment certificate, if you filed one: TCEQ's steps for TXG670000 coverage say to keep a copy of the NOI and the acknowledgment certificate onsite. A copy of the NOI also goes to the MS4 operator at the same time it goes to TCEQ.

Keep the sent notice itself, with its date and recipient. "We called the city" does not show 48 hours of written notice.

Do you have to send the records to TCEQ?

Only when something is wrong, or when they ask. Under Part III, Section B.12.b, a Discharge Monitoring Report is required if results show a violation of an effluent limit, due by the 20th day of the following month. An effluent violation more than 40% over the limit also needs a written report within five working days.

Noncompliance that may endanger human health, safety or the environment is reported orally or by email to the regional office within 24 hours of becoming aware of it, with a written report within five working days. That rule comes from 30 TAC §305.125(9), cited in Part III, Section B.12.a.

Otherwise the records stay with you, at the facility or readily available for TCEQ review. Part IV.4 says information the Executive Director requests to decide whether to revoke, suspend or terminate an authorization must be provided within a reasonable time, and in no case later than 30 days from the request.

What should the field record add beyond the permit list?

Proof of the conditions you cannot put in a sample bottle. Several permit conditions are physical, not chemical. A useful test-day record also captures:

• the vessel or segment tested, its contents history and the water source;
• the volume discharged and the start and stop times;
• the outlet: splash pad, paving or other surface, as Part III, Section B.1 requires;
• distance to the nearest water well and drinking water intake;
• the dechlorination method and where the sample point sat relative to it;
• dated photos of the outlet before, during and after discharge.

Part IV.7.e requires the sampling point to be downstream of any treatment and before the test water mixes with other flows. Note where you sampled. It is the first thing a reviewer will ask about a chlorine result.

Who has to keep the records?

The permittee, which is not always the crew. The owner and operator are named on an NOI, and Part II, Section C.5 says the authorization is not transferable. On jobs where the contractor runs the test for an owner, agree in writing before testing who keeps the file for three years. Contractors leave a job. The owner's obligation does not.

Name one person on the project, such as the superintendent or project engineer, as the record keeper for every test. Records split between three trucks and a group text are hard to produce in 30 days.

Does the laboratory matter?

Yes, when the result is used to show compliance. Part IV.7.g requires laboratory tests submitted to demonstrate compliance to meet 30 TAC Chapter 25, environmental laboratory accreditation. Part IV.7.b and c point to Standard Methods or 40 CFR Part 136 for sampling, holding times and analysis.

For total residual chlorine, the permit's minimum analytical level is 0.033 mg/L. Write down the method and its detection level, since the permit says a result below detection is reported as zero only when the method is as sensitive as that level.

Limits: this article summarizes TXG670000 and TCEQ's coverage steps as of October 2026 for general education. Owners, cities and contracts often set longer retention or extra records. Check those, and have your engineer confirm what applies to your discharge.

Frequently asked questions

How long do we keep hydrostatic test water records in Texas?

At least three years from the date of the record under TXG670000 Part IV.9, longer if TCEQ asks. Your contract or the owner's policy may require more.

Do we need records if the vessel did not need an NOI?

Yes. The NOI exemption in Part II, Section C.4 depends on meeting all applicable permit conditions, and the monitoring, notice and retention requirements are among them.

Is a text message to the city enough notice?

The permit calls for notice in writing at least 48 hours before discharge. Keep whatever you send, with its date and recipient, so you can show it was sent in time.

I'm a project engineer for a Texas pipeline contractor and our chlorine readings for the last month are in three different notebooks. What should I do now?

Gather them into one record by segment and date, note any gaps honestly, and do not fill readings in after the fact. Then set up one form for every test from here on, with the permit's seven monitoring items, the notice dates and outlet photos.

We're a developer in Texas and our contractor ran the main tests. Do we need copies of their records?

If you are the owner or operator on the authorization, get copies before the contractor demobilizes. Part IV.9 puts retention on the permittee, and you may be the one TCEQ asks.

Related resources

• Hydrostatic Test Water: What Texas Developers and Contractors Need to Know Before Discharge
• The Cost of Non Compliance: What TCEQ Enforcement Patterns Reveal About Unpermitted Test Water Discharges
• Chlorine Neutralization Before Discharge: The Field Step Contractors Skip Until It Becomes a Compliance Problem
• New Water Main Disinfection and Test Water Discharge: How to Coordinate AWWA Standards with TCEQ Rules

Need a test water record that holds up to a TCEQ request?

We set up the discharge plan and the field forms before testing starts, so every test produces the record the permit asks for.

We specialize in:

• Hydrostatic test water discharge planning
• Construction administration and field documentation
• Water distribution design
• SWPPPs and erosion and sediment control plans
• TCEQ permitting support

Modern Engineering Solutions, McKinney, Texas. Contact: (214) 833-6748 or mod-eng.com