MARINE CORPS BASE QUANTICO, VA -- Levels of Total Trihalomethanes (TTHM) Above Drinking Water Standards
Marine Corps Base Quantico (MCBQ) routinely monitors its drinking water to ensure compliance with National Primary Drinking Water Regulations. While there were no exceedances during the fourth quarter of 2025, our water system did exceed the Primary Maximum Contaminant Level (PMCL) for Total Trihalomethanes (TTHM) for the 2025 calendar year at two sampling locations. The average level of TTHM for calendar year 2025, was 0.092 mg/L at Bobo Hall and 0.087 mg/L at the 2700 Block Tank. These levels exceed the annual average standard of 0.080 mg/L.
This is not an immediate risk. If it had been, you would have been notified immediately. You do not need to use an alternative (e.g., bottled) water supply, or boil your water.
What happened?
The elevated TTHM levels were caused by a reduced flow of water due to the remote location of the sampling sites. This allowed increased contact time between chlorine and natural organic matter, resulting in excess buildup of TTHM. Some people who drink water containing high levels of TTHM over many years may experience problems with their liver, kidneys, or central nervous system, and may have an increased risk of getting cancer. There are no immediate health risks based on these levels; however, if you have specific health concerns, consult your doctor.
What is being done?
We are addressing elevated TTHM levels by optimizing the water treatment process and increasing system-wide flushing to reduce water age. These changes have already dropped the fourth quarter TTHM levels to 0.044 mg/L at Bobo Hall and 0.058 mg/L at Block Tank, well below the PMCL of 0.080 mg/L. We expect to sustain these improvements and lower the rolling average below the regulatory standard, bringing MCBQ back to compliance. Disinfection byproduct levels will be re-tested in February 2026 per our regulatory schedule.
Additional Information:
Please share this information with all others who drink this water, especially those who may not have received this notice directly. You can do this by posting this notice in a public place or distributing copies by hand or email.
For more information, visit http://www.quantico.marines.mil/Water-Quality/, or contact Dr. HunHo Kim, Supervisory General Engineer, at 703-432-2466. This notice is being sent to you by MCINCR-MCB Quantico Installation and Environment Division (GF).
Date distributed: 15 JAN 2026