FOSC Chem/Bio WQ Monitoring Summary
January 2019
This is a brief summary of our January 2019 results from chemical and bacterial monitoring at various locations along Sligo Creek.
Wheaton Lane
Flow volume was low. I disturbed one juvenile fish or tadpole when I arrived. Dog and raccoon tracks along the bank, with birds quite vocal today. Substrate is covered in dark gray silt and heavy algae layer. Ammonia-N level low at 0.06 mg/L. pH and temp were seasonally appropriate. Salinity/TDS/conductivity were high, as would be expected with winter's road salt application. Chlorine levels were surprisingly high, as were surfactants at 2.6 ppm. Noise level slightly above usual at 51 dB, air quality in the very good range.
Dennis Avenue
Volume was moderate to high here, which is interesting since it's only about half a mile downstream from the Wheaton Lane site. Ammonia-N level at 0.02. Surfactants were about 1.6 mg/L. Chlorine levels lower were about half of those at the Wheaton site. Salinity/TDS/conductivity were about 20% lower than Wheaton and near the standard winter averages. Saw three fish fry, one parent and child playing nearby. Noise levels around 53 dB - normal here - and air quality excellent (about half Wheaton Lane's PM2.5 and PM10 numbers).
Flora Lane
The water in this outfall/trib was had full but moderate flow. Substrate appeared to have more algae and fine sand then previously. Ammonia-N was 0.02, surfactants jumped to 3.4 ppm - high for this site, as well as most others. Free and total chlorine were lower than recently at 0.07 and 0.11, respectively. Water temp here was about 2 degrees warmer than nearby tribs or the main channel, which appears to be a consistent pattern. Conductivity, TDS and salinity were about a third lower than Wheaton Lane - the opposite of what we saw in November 2018. About 12 juvenile fish spotted. Noise around 53 dB and air quality excellent (interesting since this site is about 150 meters from the Beltway).
Dallas Avenue
Volume was low and slow. Cobbles covered with algae, pebbles and sand clear. No animals or tracks seen. Ammonia-N levels at 0, surfactants halved back down to 1.2 ppm. Salinity, TDS, and conductivity levels between Wheaton and Dennis readings. Chlorine levels very low this time around. Noise levels were about 54 dB, which is quieter than usual. AQ was excellent. Lots of bikers out.
You can view previous WQ Monitoring Summary reports here:
Results from
Periodic Outfall Monitoring
Along Sligo Creek
FoSC and the Center for Watershed Protection (CWP) Apply Scientific Testing to Improve Sligo Creek
Several outfalls into Sligo Creek are tested periodically by volunteer Pat Ratkowski. Pat tests for ammonia, temperature, and pH to discover illicit discharge problems which may then be reported to the County. An illicit discharge detection and elimination (IDDE) program is a requirement of the County’s Municipal Separate Storm Sewer (MS4) permit. Recent research conducted by the Center for Watershed Protection (CWP) in Sligo Creek and Baltimore City has indicated that illicit discharges are a much greater contributor of nutrient and bacteria pollution than was previously known. Their elimination can help make significant progress towards meeting local and Bay-wide total maximum daily loads (TMDLs). CWP has produced national guidance for developing and implementing IDDE programs, which includes identification of the most appropriate parameters to detect illicit discharges, many of which have sewage components. Volunteers can test for these recommended parameters at outfalls to help find illicit discharges and monitor problematic outfalls over time.
Map of Outfall Monitoring Sites