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Long Term 2 Enhanced Surface Water Treatment Rule

Information regarding the Long Term 2 Enhanced Surface Water Treatment Rule (LT2) source water monitoring for public water systems.

LT2 Schedule

LT2 requires public water systems that use surface water, groundwater under the direct influence of surface water (GUI), or rainwater to sample their source water during two rounds of sampling. The rule established a schedule for the two rounds of sampling which was completed in April 2019.  For a public water system (PWS) that places a new source in service, the following will occur:

  1. The PWS is required to notify the TCEQ LT2 Program of the intent to place an LT2 qualifying source into service PRIOR to obtaining TCEQ approval to use the source. The notification can be emailed to LT2@tceq.texas.gov or can be a letter mailed to the following address:

Technical Review and Oversight Team (MC 159)
LT2 Program
Texas Commission on Environmental Quality
P.O. Box 13087
Austin, Texas 78711-3087

  1. The notification to the TCEQ LT2 Program will initiate the process of determining the population size your PWS serves, so that your PWS Schedule can be determined. After your Schedule is determined you will be provided with a template LT2 sampling plan based on your Schedule. Your Schedule will determine the required testing:

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LT2 Rule Schedules

Schedule

PWS Population

Required Tests

Sampling Requirements

1 At least 100,000 CryptosporidiumE. coli,
Turbidity
Once per month for two years
2 50,000 to 99,999 CryptosporidiumE. coli,
Turbidity
Once per month for two years
3 10,000 to 49,999 CryptosporidiumE. coli,
Turbidity

Once per month for two years

4

9,999 or less E. coli Every two weeks for one year

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LT2 Sampling Plan

Upon receiving an email or mailed letter from the TCEQ LT2 Program requesting the submittal of an LT2 sampling plan, a PWS is required to complete and submit the sampling plan to the TCEQ LT2 Program. Submittal can be via email or a mailed hard copy, using the email or physical address above.

What is in an LT2 sampling plan? An LT2 sampling plan details PWS specific information for sampling and testing your source water. The following information is included in a sampling plan (help with PDF files):

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How to Complete an LT2 Sampling Plan

Upon receiving an LT2 sampling plan, you will notice that some of the PWS facility information is completed. Here is guidance on how to complete an LT2 sampling plan:

  1. Sample Location Worksheet:
    1. Review the entries completed by the TCEQ and edit as needed.
    2. Enter the point of contact information.
    3. Complete the information for lines 4 through 8 for each source.
    4. If not all of your current LT2 sources are present, use the “Source 2 - 4” columns.
  2. Sampling Schedule:
    1. The sampling schedule is based on the Schedule number of your PWS. The sample plan provided by the TCEQ will include one of the following schedules:
      1. Sampling Schedule – Schedules 1, 2, or 3: This sampling schedule includes laboratory and sample date information for Cryptosporidium, E. coli, and turbidity.
      2. Sampling Schedule – Schedule 4: This sampling schedule includes laboratory and sample date information for E. coli only.
    2. For each test on the sampling schedule, perform the following:
      1. Guidance on the selection of laboratory: Prior to selecting a laboratory to perform work, use the “Sample Analysis Methods” Word document to assure that the method used by a laboratory is approved for analysis of LT2 samples.
      2. Cryptosporidium: Enter the name of the laboratory that will perform the testing. The laboratory is required to be EPA approved. EPA approved laboratories can be found on the EPA Cryptosporidium webpageExit the TCEQ. 
      3. E. coli: Enter the name of the laboratory that will perform the testing. The laboratory is required to be TCEQ National Environmental Laboratory Accreditation Program (NELAP) accredited under the drinking water matrix for an enumeration method (a method that yields a number for a result instead of Presence/Absence). TCEQ NELAP accredited laboratories can be found at TCEQ NELAP
      4. Turbidity: The laboratory or PWS performing the turbidity analysis must be TCEQ approved or TCEQ NELAP accredited. Please note the following:
        1. If your PWS is performing turbidity analyses in-house for SWMOR reporting, then you are approved for reporting turbidity for LT2 requirements.
        2. If you will be sending turbidity samples to a contract laboratory, the laboratory must be TCEQ NELAP accredited for the turbidity analysis.
    3. Entry of Sample Dates
      1. Schedules 1,2, or 3
        1. The TCEQ recommends that you contact the laboratory which will be performing the Cryptosporidium analysis prior to determining a schedule to verify the availability of the laboratory on the declared sample date(s).
        2. The TCEQ recommends scheduling a sampling date on a Wednesday, if possible. This allows the most flexibility in meeting compliance with 30 TAC §290.111(b)(4)(C), which requires that samples be collected within ±2 days of a TCEQ approved sampling date.
        3. Sampling frequency: Once a month for 24 consecutive months.
        4. Matrix spikes for Cryptosporidium: In addition to the 24 monthly samples, 2 matrix spike samples must be collected. One spike at the beginning of the sampling period and a second spike towards the end of the sampling period.
      2. Schedule 4
        1. The TCEQ recommends that you contact the laboratory which will be performing the coli analysis prior to determining a schedule to verify the availability of the laboratory on the declared sample date(s).
        2. The TCEQ recommends scheduling a sampling date on a Wednesday, if possible. This allows the most flexibility in meeting compliance with 30 TAC §290.111(b)(4)(C), which requires that samples be collected within ±2 days of a TCEQ approved sampling date.
        3. Sampling frequency: Every 14 days for a period of one year, for a total of 26 samples.
  3. Sampling Location Schematic: A PWS can submit one of the following as a schematic which identifies the LT2 sample collection point:
    1. Choose one of the schematics in the “Diagrams for Sampling Location” PDF provided by the TCEQ which best represents the PWS LT2 sample collection point(s) location; or
    2. Submit a PWS custom generated schematic which identifies the LT2 sample collection point(s) location.

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Sampling Plan Submittal to the TCEQ

After an LT2 sampling plan is completed, a PWS is required to submit the LT2 sampling plan to the TCEQ LT2 Program:

What to submit:

  1. Sample Location Worksheet
  2. Sampling Schedule
  3. Diagram for Sampling Location. For a facility with multiple collection points, one diagram may be needed per sampling location. If multiple diagrams are provided, clearly label each diagram. 

Where to submit the LT2 sampling plan:

  1. Email: Sampling plans can be emailed to LT2@tceq.texas.gov, or
  2. Mail: A hard copy of a sampling plan can be mailed to the following address

Technical Review and Oversight Team (MC 159)
LT2 Program
Texas Commission on Environmental Quality
P.O. Box 13087
Austin, Texas 78711-3087

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Guidance to Assist with Successful LT2 Sampling

  • Bacteriological sampling containers:  If distribution samples are collected at the same time as source water bacteriological sampling, clearly label source water samples as “RAW.”
  • Bacteriological test methods:  If distribution samples are collected at the same time as source water bacteriological sampling, clearly denote on a chain of custody that enumeration (numeric result) is required for the LT2 sample(s).
  • Scheduling: Verify that the laboratory is able to provide testing services on dates indicated on your sampling schedule. If a PWS schedules a collection date on a holiday without verifying if their chosen laboratory is open, sample analyses may not occur as planned. The PWS’s chosen laboratory should assist with sample collection scheduling to assure that testing services are available on PWS chosen sampling dates.
  • Shipping/packing samples: A PWS should coordinate with their chosen laboratory regarding sample containers, how to ship samples, and shipping containers (coolers).  Many laboratories have instructions that can be provided to a PWS for sample collection/shipping.   
  • Reporting of results: Some PWSs assume that a laboratory will report results to the TCEQ for a PWS. A PWS will need to coordinate with their chosen laboratories regarding the emailing of laboratory reports to the TCEQ. A PWS, not the laboratory, is ultimately responsible for submittal of laboratory reports to the LT2 Program. It is acceptable for a laboratory to submit reports to the TCEQ for a PWS, but you may need to request that a laboratory submit reports to the TCEQ.

More information can be found in the EPA LT2 sampling pocket guideExit the TCEQ.

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Submittal of Results

Systems should begin sampling per the schedule detailed in their sampling plan. Systems should submit a copy of the sample reports from their laboratory to the TCEQ.

  1. When to submit: Reports must be submitted on a monthly basis.

Submittal Deadline: The 10th day of the month following the period for which you are reporting. For example, for the samples collected in the month of May, submit the sample results by June 10.

  1. What to submit: A copy of the complete report from an EPA approved Cryptosporidium laboratory (for Cryptosporidium samples), a TCEQ NELAP-accredited laboratory (for coli samples), and a PWS approved by the TCEQ to perform turbidity (for turbidity samples). A summary of results can be submitted but is not a substitute for a laboratory report.
  2. How to submit a report to the TCEQ LT2 Program:
    1. Preferred method - Email to: LT2@tceq.texas.gov; or
    2. Mail a hard copy to the address above. Please note that if a report is emailed, there is no requirement to mail a hard copy to the TCEQ.

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What Happens Next?

After you have submitted a results report for the final scheduled sampling date, the following occurs:

  1. The TCEQ LT2 Program evaluates the results and issues a Bin classification letter. If the letter is for Round 1, the letter will contain the date by which Round 2 sampling is required to be initiated.
  2. For Schedule 4 systems, please note that if the average for coli exceeds 100 MPN/100 mLs or 100 CFU/100 mLs, a new schedule will need to be submitted and Cryptosporidium sampling will be required for the 24-month period specified above. The need for Cryptosporidium sampling may be determined before all of the sampling noted on an E. coli sampling schedule is complete.
  3. Upon receipt of a Bin classification letter, a PWS is notified of one of the following:
    1. The Bin classification letter is a Round 2 letter and no further sampling/testing is required for the sources identified in the letter; or
    2. The Bin classification letter is a Round 1 letter and the PWS is notified of a date by which Round 2 sampling is to be initiated.

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Second Round of Sampling (Round 2)

Please note that Systems should begin sampling for Round 2 of LT2 as per the following:

  • Initiate Round 2 sampling as per the date specified in the PWS Round 1 Bin classification letter.

The Round 2 initiation of sampling date is based on the requirement specified in 30 TAC §290.111(b)(4)(A)(ii) to begin the second round of special raw surface water monitoring no later than six years after initial bin classification.

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Rules for These Requirements

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