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Public water system record

CLWSC Canyon Lake Shores

Serves an area of Comal County, TX that includes Canyon Lake and Bulverde · 44,196 people served

Federal records show 4 health-based violations and 11 monitoring/reporting issues for CLWSC Canyon Lake Shores in the last ten years. The most serious issue in this window was a Total Trihalomethanes (TTHMs) violation that EPA lists as archived, not resolved.

  • TX0460019
  • CANYON LAKE
  • TX
  • 44,196 served

System profile

Source water Surface water
ZIP 78133
EPA system ID TX0460019

Verify this system on EPA ECHO →

Health-based violations, last 10 years
4
Resolved
2
Unresolved
0
Archived by EPA
2
Any acute record
Yes
Monitoring issues, last 10 years
11

Key facts

  • CLWSC Canyon Lake Shores draws water from 16 wells and 1 surface water intake.
  • Highest measured level in the last 10 years: Total Trihalomethanes (TTHMs), 0.129 mg/L, federal limit 0.08 mg/L (1.6 times the limit), 2025.
  • Most recent enforcement action: boil water order by Texas, July 2025.
  • Record on file since 2002, with 7 health-based violations before October 19, 2016.
  • Lead pipe inventory: 0 lead and 4,892 unknown out of 12,918 service lines.

Check whether CLWSC Canyon Lake Shores serves your address

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Health-based violations

Since October 2016

Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.

Contaminant Rule family Start date Status Acute
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.129 mg/L, federal limit 0.08 mg/L (1.6 times the limit)
 220 Oct 1, 2025 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
 120 Jul 1, 2025 Resolved Yes
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
 120 Jul 1, 2025 Resolved Yes
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.113 mg/L, federal limit 0.08 mg/L (1.4 times the limit)
 220 Jul 1, 2025 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No

Monitoring and reporting issues

Since October 2016

Missed tests or reports, not contaminants found above a limit.

Issue Start date Status
Public Notice
OTHER
 Dec 16, 2025 Resolved
Total Trihalomethanes (TTHMs)
Monitoring and reporting
 Feb 4, 2025 Resolved
Revised Total Coliform Rule
Monitoring violation
 Oct 1, 2024 Resolved
Revised Total Coliform Rule
Monitoring violation
 Oct 1, 2021 Resolved
Surface Water Treatment Rule
Monitoring and reporting
 Feb 1, 2021 Resolved
Aldicarb
Monitoring and reporting
 Jan 1, 2021 Resolved
Carbofuran
Monitoring and reporting
 Jan 1, 2021 Resolved
Aldicarb sulfone
Monitoring and reporting
 Jan 1, 2021 Resolved
Aldicarb sulfoxide
Monitoring and reporting
 Jan 1, 2021 Resolved
OXAMYL
Monitoring and reporting
 Jan 1, 2021 Resolved
Public Notice
OTHER
 Sep 1, 2010 Resolved

Full record since 2002

EPA's records for CLWSC Canyon Lake Shores go back to 2002. Before October 19, 2016 they list 7 health-based violations (7 resolved) and 56 monitoring or reporting violations.

Violations that began in Health-based Monitoring and reporting
2000s 6 51
2010 to October 18, 2016 1 5
2020s 4 10

Most recent health-based violation before October 19, 2016: Total Coliform, began September 2010, Resolved.

Show all 7 health-based violations before October 19, 2016
Contaminant Start date Status
Total Coliform
Contaminant limit exceeded
 Sep 1, 2010 Resolved
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 0.077 mg/L, federal limit 0.06 mg/L (1.3 times the limit)
 Jan 1, 2005 Resolved
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.088 mg/L, federal limit 0.08 mg/L (1.1 times the limit)
 Jan 1, 2005 Resolved
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 0.079 mg/L, federal limit 0.06 mg/L (1.3 times the limit)
 Oct 1, 2004 Resolved
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.099 mg/L, federal limit 0.08 mg/L (1.2 times the limit)
 Oct 1, 2004 Resolved
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 0.085 mg/L, federal limit 0.08 mg/L (1.1 times the limit)
 Jul 1, 2004 Resolved
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 0.072 mg/L, federal limit 0.06 mg/L (1.2 times the limit)
 Jul 1, 2004 Resolved

Enforcement actions

Texas regulators took 1 formal enforcement action against CLWSC Canyon Lake Shores and issued 1 boil water order between 2006 and 2025. The most recent was a boil water order in July 2025.

Date By Action Violations covered
Jul 6, 2025 Texas Boil water order 1 violation (1 health-based): Interim Enhanced Surface Water Treatment Rule
Feb 5, 2006 Texas Compliance order with a penalty 6 violations (6 health-based): Total Trihalomethanes (TTHMs), Haloacetic Acids (HAA5)

What the violations mean

Total Trihalomethanes (TTHMs)

2 incidents

Disinfection byproduct levels exceeded the federal limit

Long-term TTHM exposure may increase bladder cancer risk

Interim Enhanced Surface Water Treatment Rule

2 incidents

The system did not meet a filtration or treatment requirement for surface water

Inadequate treatment of surface water can let pathogens such as Cryptosporidium and Giardia through

Where the water comes from

CLWSC Canyon Lake Shores draws water from 16 wells and 1 surface water intake. It also buys water from Gbra Western Canyon Water Supply. 2 other community water systems and 2 smaller public systems such as schools, businesses or campgrounds buy water from CLWSC Canyon Lake Shores.

Buys water from

Community systems that buy water from it

Annual water quality report

CLWSC Canyon Lake Shores must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.

Systems serving 10,000 or more people must mail or deliver the report to every customer, and from 2027 they must send it twice a year.

Find a posted report with EPA's Consumer Confidence Report search

Testing your own water

To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by Texas.

Certified drinking water labs by state EPA guidance for private wells