Bacteria Count - COPY
The LFWA fecal bacteria monitoring program starts Wednesday, June 1. We will once again be monitoring sites on the Willett and Little Falls Branches for fecal bacterial levels. Sites that FAIL (bacteria levels above 410 MPN/100 ml) are deemed unsafe by MD State Standards for water play.
June 1 Testing Results
Little Falls Branch: Two sites PASS. Two Sites FAIL.
Willett Branch: All Three Sites FAIL. The current E. coli fecal bacteria count at all sites is VERY HIGH
2022 Testing Locations
Data from Willett and Little Falls Branch Sites
| Date | Site | Bacteria (MPN/100mL) | Pass/Fail | pH | Air Temp (C) | Water Temp (C) |
|---|---|---|---|---|---|---|
| 6/1/2022 | WBA**: Willett Branch at Hillandale Townhouses | 1421 | Fail | 6 | 23 | 18 |
| 6/1/2022 | WB1: Willett Branch at Norwood Park | 1553.1 | Fail | 6 | 23 | 18 |
| 6/1/2022 | WB3: Willett Branch at Morgan Dr. | 1046.2 | Fail | 6 | 22 | 19 |
| 6/1/2022 | LFB1: Little Falls Branch at Somerset Pool | 313 | Pass | 7 | 23 | 20 |
| 6/1/2022 | LFB2: Little Falls Branch below Massachusetts Ave. | 435.2 | Fail | 7 | 22 | 20 |
| 6/1/2022 | LFB3: Little Falls Branch at Pedestrian Bridge 1 | 313 | Pass | 7 | 24 | 21 |
| 6/1/2022 | LFB4***: Little Falls Branch in Brookmont | NS | N/A | NS | NS | NS |
** WBA test diluted to 10%, as bacterial counts have exceeded the 2,420 limit of the straight test.
*** LFB4 unable to be tested this week, NS = Not Sampled
Pass/Fail Criteria
E. coli levels up to 410 considered passing. Pass/Fail interpretations are based on Maryland and the District of Columbia's water quality single-sample standards for E. coli in surface waters.
The amount of E. coli is reported as Most Probable Number (MPN) per 100 milliliters (ml). Whereas counts up to 410 are considered passing, the following are benchmarks used throughout the Potomac River watershed for reporting E. coli levels in streams:
HIGH – greater than 410 MPN/100 ml.
MODERATE – 126 to 410 MPN/100 ml
LOW – 125 MPN/100 ml or less
Lab work is done by the Anacostia Riverkeepers.
*Basic testing measures levels up to 2,419.6. Totals over that count are reported as >2,419.6.
| Date | Status | Site | E.coli (MPN/100 ml) | Air Temp. (°C) | Water Temp. (°C) | pH |
|---|---|---|---|---|---|---|
| 9/15/2021 | FAIL | WB1: Willett Branch - Norwood Park | 920.8 | 24 | 23 | 6 |
| 9/15/2021 | PASS | LBF1: Little Falls Branch - Somerset Pool | 344.8 | 20 | 22 | 6 |
| 9/15/2021 | PASS | LFB2: Little Falls Branch - Below Mass. Ave at Second Bench | 387.3 | 23 | n/a | 7 |
| 9/15/2021 | FAIL | LFB3: Little Falls Branch - Below Mass. Ave.at First Pedestrian Bridge | 648.8 | 23 | n/a | 7 |
| 9/15/2021 | FAIL | LFB4: Little Falls Branch - Brookmont | 770.1 | 20 | 22.5 | 6 |
LFWA Monitoring program
By testing for bacteria, we hope to inform residents of the safety of the water for splashing and wading as well as determine if there is a need for sewer line repairs in the watershed. After a two week pilot program in the fall of 2020, we decided to test the creek regularly for E. Coli during the summer months of 2021 in five locations. Volunteers also test the pH and measure air and water temperature. The samples are analyzed at a water quality lab run by Anacostia Riverkeeper. Results will be posted on our Facebook page, on kiosks close to the creek, on community listservs, on TheSwimGuide.org and on our website.
2022 Locations (as shown on the map):
Willett Branch at the end of Willett Parkway where path curves to Norwood Park – WB1
Willett Branch at the end of Willett Parkway where path curves to Norwood Park – WB2
Willett Branch at the end of Willett Parkway where path curves to Norwood Park – WB A
Little Falls Branch upstream from the Somerset pool – LFB1
Little Falls Branch downstream from Mass. Ave. bridge at the second bench – LFB2
Little Falls Branch downstream from Mass. Ave. bridge at the first pedestrian bridge – LFB3 (coming July 17)
Little Falls Branch on Potomac River side of MacArthur Blvd in Brookmont – LFB4
2022 Testing dates - every Wednesday, June 1 to September 14
what is fecal bacteria?
Fecal coliform bacteria are found in the feces of warm-blooded animals such as people, pets, and wildlife. Fecal coliform contamination in streams can come from leaking sewer pipes and many small sources such as pet waste in stormwater runoff. Wildlife and birds also contribute. As the amount of fecal coliform bacteria in the water increases, the risk of contracting a waterborne illness increases.
Fecal bacteria Health risks
The best indicator of the health risk from recreational water contact is E. coli, which is a species of fecal coliform bacteria that is specific to fecal material from humans and other warm-blooded animals. The presence of E. coli is also used as an indicator to monitor the possible presence of other more harmful microbes, such as Cryptosporidium, Giardia, Shigella, and norovirus. Some of the symptoms of illness associated with fecal coliform bacteria contamination are upset stomach, diarrhea, ear infections, and rashes. However, some bacteria, such as some strands of E coli, hepatitis, and Salmonella, can have very severe health effects.
Fecal Coliform Creates Problems for fish and Aquatic Plants
High levels of fecal coliform can cause other problems as well. Sewage and other contaminants contain nitrogen and phosphorus, which act as fertilizer for algae and other aquatic plants. An overgrowth of plants can deplete dissolved oxygen needed by fish and other aquatic animals. affect the natural acidic-alkaline (pH) balance of water, create odor problems, and affect property values.
The possibility of bacterial contamination increases in the summer months, which is also the time when more people come in contact with the streams in the watershed.
2021 Trend Charts
Historical Data
Click HERE for a report of our 2021 findings
In September 2020, LFWA volunteers collected water samples at 5 locations to test for E. coli concentrations. E Coli concentrations were HIGH at some of the locations.
Click for the September 2020 report
By Court decree, WSSC monitored the watershed between 2009 and 2012. They did a DNA testing and found high levels of human fecal matter as well as fecal matter from dogs, deer, birds and other wildlife.