Systematically monitoring and recording the water quality of Sligo Creek, and educating the public about the importance of clean water for fish and wildlife
What the Water Quality Committee is Doing Now
WQ Committee to Continue Two SaltWatch Initiatives This Winter – Volunteers needed!
1) Salt Watch Stream Monitoring A program in which volunteers test the level of road salt in Sligo waters before, during and after a snow event. The WQ Committee provides the simple testing kits through a partnership with the Izaak Walton League. Committee members provide guidance on selecting a location to test and coordinate testing dates/times across the Sligo watershed. Check out the FOSC Salt Monitoring Initiatives page for more information on volunteering for winter 2022-2023.
2) Excessive Road/Sidewalk Salt Pile Reporting If you see an excessive salt pile in the Sligo Creek Watershed, please send an email with location, date, time and a photo to [email protected]. We will try to get the County, State or responsible party to remove excessive salt piles before they go into Sligo Creek. View the watershed map on the Maps of Sligo Creek page.
Don’t drain water – from a pool or hot water heater – into the street! It contains chlorine and goes into the storm drain and right into Sligo Creek.
Pool water, wash water, tap water, hot or cold, contains chemicals – chlorine and other compounds – that kill wildlife such as fish, salamanders, frogs, and other aquatic life, as well as plants and beneficial bacteria. Keep it out of the storm drain.
Instead, insist that your plumber drain your hot water heater into a utility sink or basement drain that goes into the sewer system, where it is treated before being released.
Nothing should go into the storm drains on the street except rain!
These special guidelines apply when draining pool water:
Volunteers will again test summer water quality

Jackson Ave testing site in Takoma Park
Water quality volunteers test 3 sites along Sligo and 1 site on Long Branch. Volunteers record water temperature, air temperature, dissolved oxygen, pH, and turbidity, and take water samples to be analyzed for bacteria at Anacostia Riverkeeper's lab.
The data from the program helps FOSC, ARK, Montgomery Parks, and state and local agencies learn more about the chemical and biological health of Sligo and Long Branch. To volunteer for the Summer 2023 team, please contact the Water Quality committee chair Pat Ratkowski at [email protected] See data from 2022 and the two previous years on the ARK/FOSC Summer Volunteer Water Quality Monitoring and Data page.
USGS in Sligo Creek - presentation to FOSC
In Spring of 2022, Chuck Walker of the regional USGS MD-DE-DG Water Science Center spoke on the health and water quality of Sligo Creek. The Water Science Center has partnered with MoCo DEP to collect continuous water quality data on 7 parameters at the Maple Ave gauge. How is Sligo faring compared to other regional streams? Chuck told us about the long term trends and implications for Sligo as our area gets more densely populated. Check out the video on FOSC's YouTube channel.
Spotlight on: Microplastics in our waterways
The impact of microplastics is an important issue in Montgomery County where it is proposed for a section of Ellsworth Drive in downtown Silver Spring. FOSC opposes the use of artificial turf on Ellsworth. See the Ellsworth Synthetic Turf page under the Current Issues page of the Advocacy tab for more information on FOSC's concerns about synthetic turf.
FOSC Water Quality Committee volunteers have worked to create public awareness on the unseen impact of plastic pollution on humans and on waterways, including fresh waterways such as Sligo Creek. Dr. Jesse Meiller and Dr. Kathy Michels discussed the issue at a February 2020 talk sponsored by FOSC.
Scientists are finding that microplastics are everywhere in our waterways, whether salt water or freshwater. Ongoing research shows that most microplastics are harmful to living creatures and plants life due to their chemical content which does not break down (known as "forever chemicals".) Synthetic turf is one example of a product that leaches "forever" chemicals as well as plastic bits that are ingested by wildlife.
Report on ARK/FOSC Summer Volunteer Water Quality Monitoring Program
"The Coliform results were disappointing. I don't believe any site in the program ever met fishable or swimmable water standards during the summer, though not entirely unexpected given what our FOSC program has found over the years. I will share highlights from the full results on the WQ page shortly. FOSC participated again in 2021, and I think ARK is hoping to expand the scope of the program to new sites and tributaries if possible."
-- Pat Ratkowski, Water Quality Committee Chairperson
Ongoing Water Quality Committee programs
Volunteers for the Water Quality committee are also running several ongoing programs to help preserve and plan for the health of Sligo Creek:
Wouldn't it be great if the water in Sligo Creek were clean enough so that people could wade or swim in it without worry? The FOSC Water Quality Committee is working to improve the water quality of Sligo Creek so that it will meet its potential as a natural and recreational resource. While it is currently home to a surprising variety of wildlife, keeping the creek waters healthy for wildlife is an ongoing challenge as the region becomes more populated.
The Committee and FOSC’s members are working with local agencies and nonprofit organizations to meet the challenge, knowing that a healthier Sligo Creek both enhances our everyday lives and benefits the waters and wildlife of the Anacostia Watershed, the Potomac River, and the Chesapeake Bay.
Are you interested in improving Sligo's water quality?
Consider joining the Water Quality Committee!
The Water Quality Committee works on projects aimed at understanding and improving Sligo Creek's water quality.
FOSC’s Chemical Water Quality Team regularly monitors 13 sites along the Creek and its tributaries for ten different parameters, keeping track of the Creek’s water quality and the condition of its channel and surrounding habitats. Take a look at the Team’s summary findings on the Water Quality Monitoring Data page. A sample FOSC Water Quality Monitoring Report and a sample Field sheet appear elsewhere on this page.
We also monitor macroinvertebrates for the Maryland Department of Natural Resources Stream Waders program, the Izaak Walton League's Save Our Streams program, and the Audubon Naturalist Society program.
We try to learn about and promote Sligo Creek monitoring being done by others, and when appropriate, use our findings to advocate for local, county and regional policy changes. Information about our activities is posted on the Friends of Sligo Creek newsletter and listserv. Join FOSC to receive the newsletter.
If you would like to join the committee, participate in Committee activities or have questions, please email Pat Ratkowski, Committee chairperson, through the Contact FOSC page or email WQ at fosc.org.

Coliform bacteria testing plate
Sample FOSC Water Quality Monitoring Report
Sample FOSC Water Quality Monitoring Field Sheet
The Sligo Creek Water Quality - Selected Bibiliography page contains further reading on Sligo Creek Water Quality.