Today, the Baltimore City Department of Public Works (DPW) announced that the latest test samples found no traces of Cryptosporidium oocysts in the Druid Lake Reservoir. The test results were delivered to DPW on Tuesday, Oct. 3, 2023.

On Thursday, Sept. 28, 2023, DPW announced that it had discovered low levels (0.09 Cryptosporidium Oocyst/Liter) of the microscopic parasite Cryptosporidium during a routine test of the Druid Lake Reservoir. The levels of Cryptosporidium detected in the water supply indicated a low risk for the general population. Cryptosporidium is a microorganism commonly found in lakes and rivers, which can potentially cause gastrointestinal problems, particularly, in those who are immunocompromised.

This guidance is in alignment with DPW’s annual water quality reports, which feature the following standing notification on the health effects of uncovered treated water reservoirs: “Uncovered reservoirs used to store treated drinking water can be open to contamination from animals, such as bird or insects.”

Links to the most recent Water Quality Report can be found here and appear on the water bills mailed to City and County water customers.

Although the water remains safe for the general public to consume, at this time out of an abundance of caution, the Maryland Department of Health and the Maryland Department of the Environment advises people with severely weakened immune systems to continue to:

• Drink bottled water, OR
• Boil water for one minute before consuming, OR
• Filter tap water using a filter labeled to ANSI/NSF 53 or 58 standards, or a filter designed to remove objects 1 micron or larger. These may be labeled “absolute 1 micron.” (i.e., not Brita-type filters)

DPW on Track to Cover Finished Water Reservoirs

DPW is working to complete work on the two remaining uncovered finished water reservoirs at Druid Lake and Ashburton by the end of the year. The completion of these projects, which have been an ongoing effort, will add additional safeguards to the City’s treated drinking water supply from Cryptosporidium and other contaminants. 

At Druid Lake and Ashburton, massive underground tanks are being built to protect the treated water supply. Work on these projects has unfortunately been subject to unavoidable and extensive delays due to unforgiving site conditions, weather delays, supply and worker shortages caused by the COVID 19 pandemic, supply chain delays etc.

However, work is scheduled to be completed on Druid Lake on Dec. 30, 2023, and on Ashburton on Nov. 30, 2023, in compliance with the timeline agreed on by the City and EPA, under a modified Administrative Order of Consent.

How DPW is Protecting Public Health
While work on the remaining uncovered reservoirs is being completed, DPW will take the following measures to reduce the risk of Cryptosporidium and to keep the public informed:

Continued Monitoring for Cryptosporidium
DPW has committed to sampling for Cryptosporidium and Giardia at the Ashburton and Druid Lake Reservoirs on a weekly basis. Each of these test results will be posted on the DPW website. Weekly testing for the finished drinking water reservoirs started the week of October 2, 2023. 

Public Notification
DPW will continue to notify the public of all detections through press releases to local media, social media posts, email notifications, and other avenues. DPW will also continue to coordinate with the Baltimore City Department of Health to reach facilities that serve people who may be at higher risk of more serious disease.

 Public Health Coordination
DPW will continue to collaborate with the Maryland Department of the Environment (MDE), U.S. Environmental Protection Agency (EPA), and the Maryland Department of Health (MDH) on public notification guidelines and to ensure that the message of water safety is clearly communicated to the public.