Radionuclide Testing for Approval of Well Completion
Required testing, required checklists, and other guidance for submitting well completion data in order to secure approval to use the well.
Well Completion Checklist for Plan Review
In order to receive approval to use your public water system well, you must submit each item on the Public Well Completion Data Checklist for Approval to Use (Step 2), including specified chemical testing. For specific counties, you must also conduct radionuclide testing.
Required Radionuclide Testing for Specific Counties
If you construct a well in areas with elevated radionuclide levels, listed in Table 1, you must conduct radionuclide testing for community, non transient non community, and transient public water systems. Counties listed here have results exceeding the maximum contaminant levels for gross alpha and/or combined radium-226 and radium-228.
Table 1: Counties where Radionuclide Testing is Required
| Atascosa | Erath | Jim Wells | Medina | Tarrant |
| Bandera | Fort Bend | Kendall | Midland | Travis |
| Bexar | Frio | Kent | Montgomery | Tyler |
| Bosque | Garza | Kerr | Moore | Upton |
| Brazoria | Gillespie | Kleberg | Parker | Val Verde |
| Brewster | Gray | Liberty | Pecos | Victoria |
| Burnet | Grayson | Llano | Polk | Walker |
| Concho | Harris | Lubbock | Presidio | Washington |
| Culberson | Hudspeth | McCulloch | Refugio | Wichita |
| Dallam | Irion | Mason | San Jacinto | Williamson |
| Dawson | Jeff Davis | Matagorda | San Saba | Zavala |
Compliance-Related Information to Consider
The laboratory you use must be able to conduct analyses for gross alpha, gross beta and radium-228. Additional analysis are required if levels exceed the triggers listed in Table 2. Before you select a laboratory verify their methods of analysis.
- Exceedance of gross alpha and radium-228 triggers, the laboratory must complete specific testing, for radium-226, combined uranium, and the uranium isotopes 234, 235, and 238.
- Exceedance of gross beta triggers, which are uncommon, the laboratory must complete testing for tritium, radioactive strontium and gamma emitters.
For example, if the results for gross alpha are over 15 pCi/L and uranium is not analyzed, you will have to resample or reanalyze and resubmit required results to TCEQ. If the results for gross alpha plus radium-228 are over 5 pCi/L and radium-226 is not analyzed, you will have to resample or reanalyze and resubmit required results to TCEQ.
Table 2: Triggers for Additional Radionuclide Testing
| Contaminant (pCi/L except *) | Trigger |
|---|---|
| Gross Alpha | Performed on all samples |
| Gross Beta | Performed on all samples |
| Radium-228 | Performed on all samples |
| Radium-226 | If gross alpha + Ra-228 >5.0 pCi/Liter |
| Combined Uranium | If gross alpha >15 pCi/Liter; reported in ( g/Liter) |
| Uranium-234 | If gross alpha >15 pCi/Liter |
| Uranium-235 | If gross alpha >15 pCi/Liter |
| Uranium-238 | If gross alpha >15 pCi/Liter |
| Tritium | If gross beta >50 or the system is designated by TCEQ as vulnerable. |
| Radioactive Strontium | If gross beta >50 or the system is designated by TCEQ as vulnerable. |
| Gamma-emitting Radionuclides | If gross beta >50 or the system is designated by TCEQ as vulnerable. |
Compliance Calculations from Radionuclide Analytical Results
You must calculate radionuclide compliance for gross alpha and combined radium-226 and radium-228 from analytical results if the laboratory does not. Non-detections are calculated as a zero ("<" sign in front of a result).
- Gross alpha (pCi/L): gross alpha result - uranium-234 result - uranium-238 result - uranium-235 result = compliance level (Maximum Contaminant Level is 15 pCi/L)
- Combined radium (pCi/L): radium-226 result + radium-228 result = compliance level (MCL is 5 pCi/L)
- Combined Uranium (MCL is 30 µg/L): no calculation
Laboratory Information for Radionuclides
Public water systems are required to use a NELAP accredited laboratory for public drinking water that use approved methods of analysis for radionuclides to secure approval for a well completion data submittal. Before using any laboratory, you must verify that the laboratory is accredited to conduct the required analyses.
The analysis for radionuclides takes longer to complete than other constituents, plan accordingly. Contact PWSChem@tceq.texas.gov if you have questions about finding an accredited lab.