According to Baltimore City DPW, after routine water quality tests, elevated levels of total trihalomethanes (TTHM) were found in the water in the Sparks area.
TTHMs are by-products that form when chlorine, used to disinfect drinking water, reacts with natural organic material in the water.
Drinking water quality notices, which are required by state and federal drinking water regulations, have been sent to 600 services in the Sparks area. For more info on these notices, click here.
Even though these levels were higher-than-allowed, the water is safe to drink, DPW says.
Authorities state there is no immediate health risk and no need to boil water or take uncommon action.
What This Means for Customers
- There is nothing you need to do. Customers do not need to boil their water or take other corrective actions.
- If water were ever unsafe to drink, residents would be notified within 24 hours.
- Individuals with severely compromised immune systems, infants, pregnant people, or the elderly may wish to consult their healthcare provider about drinking this water.
Background
- TTHMs form when disinfectants, such as chlorine, react with natural organic matter in the water.
- Less than normal rainfall in Spring 2025 combined with significant hot temperatures increased water temperatures in the Prettyboy and Loch Raven Reservoirs. The warmer water from the reservoirs and drinking water treatment plants promotes interaction between chlorine and the natural organic matter in the water, thereby increasing TTHM formation.
- People who drink water containing TTHMs in excess of the MCL over many years may have an increased risk of health issues.
What DPW is Doing
Hot weather during summer months increases TTHM formation; therefore, during the summer months DPW pulled raw water from deeper depths at the Loch Raven and Liberty reservoirs. The deeper water is colder than water at higher depths. Additionally, DPW changed chemical treatment at the Montebello Water Treatment Plants to improve removal of organic compounds, which also reduced TTHM formation. DPW also maintains a comprehensive hydrant flushing program to maintain water quality throughout the water distribution system, including in the Sparks area.
Customer Information
- Baltimore County residents should call 443-263-2220.
DPW encourages residents to share this information with others who drink Baltimore City water in the Sparks area, especially those who may not have received this notice directly (such as people in apartments, nursing homes, schools, and businesses).
Scan the QR code above to access the online map, then enter your address to see if your property is in the impacted area. Residents can find additional information on the notice by reviewing the frequently asked questions [links-2.govdelivery.com] online.
