WSSC Water Quality Monitoring
Here are the 17th round of results of WSSC's fecal bacteria monitoring tests which are required by the consent decree. Many sites had high Enterococci bacteria counts this time. These results are from this WSSC report.
March 29, 2011 |
The Maryland state standards for Enterococci bacteria:
|
| Stream Site | Fecal Bacteria Results Enterococcus CFU/100mL | Bacterial Source Testing | ||||||
|---|---|---|---|---|---|---|---|---|
| Human | Avian | Canine | Deer | Horse | Miscellaneous Wildlife | Non-human Unknown | ||
| 1). Broad Creek (downstream - Henson Creek) | <10 | Too few bacteria for bacteria source determination | ||||||
| 1). Broad Creek (upstream - Henson Creek) | <10 | Too few bacteria for bacteria source determination | ||||||
| 1). Cabin John Creek (upstream) | <10 Bacteriodes: Negative | Too few bacteria for bacteria source determination | ||||||
| 1). Horsepen (upstream) | <10 (<10) Bacteroides: Negative | Too few bacteria for bacteria source determination | ||||||
| 1). Northeast Branch (upstream) | <10 | Too few bacteria for bacteria source determination | ||||||
| 1). Paint Branch (upstream) |
<10 | Too few bacteria for bacteria source determination | ||||||
| 1). Piscataway (upstream) |
<10 | Too few bacteria for bacteria source determination | ||||||
| 1). Rock Creek (upstream) |
<10 | Too few bacteria for bacteria source determination | ||||||
| 1). Seneca Creek (downstream) | <10 | Too few bacteria for bacteria source determination | ||||||
| 1). Upper Beaverdam Creek (downstream) | <10 | Too few bacteria for bacteria source determination | ||||||
| 1). Upper Beaverdam Creek (upstream) | <10 | Too few bacteria for bacteria source determination | ||||||
| 1). Watts Branch (downstream) | <10 | Too few bacteria for bacteria source determination | ||||||
| 1). Watts Branch (upstream) |
<10 | Too few bacteria for bacteria source determination | ||||||
| 1). Western Branch (downstream) | <10 | Too few bacteria for bacteria source determination | ||||||
| 1). Western Branch (upstream) | <10 | Too few bacteria for bacteria source determination | ||||||
| 16). Muddy Branch (upstream) |
15 (<10) | Too few bacteria for bacteria source determination | ||||||
| Stream Site | Fecal Bacteria Results Enterococcus CFU/100mL | Bacterial Source Testing | ||||||
| Human | Avian | Canine | Deer | Horse | Miscellaneous Wildlife | Non-human Unknown | ||
| 16). Lower Anacostia (upstream) | 15 | 0% | 43% | 12% | 10% | 14% | 21% | |
| 16). Northeast Branch (downstream) | 15 | 0% | 37% | 12% | 14% | 24% | 13% | |
| 19). Little Falls (upstream) |
20 | 0% | 33% | 9% | 12% | 27% | 19% | |
| 19). Northwest Branch (downstream) | 20 Bacteriodes: Negative | 0% | 35% | 11% | 16% | 22% | 16% | |
| 21). Indian Creek (downstream) | 25 | 0% | 35% | 9% | 9% | 17% | 17% | 13% |
| 21). Northwest Branch (upstream) | 25 Bacteriodes: Negative | 0% | 39% | 7% | 12% | 27% | 15% | |
| 23). Indian Creek (upstream) | 28 | 0% | 30% | 11% | 14% | 13% | 23% | 9% |
| 23). Seneca Creek (upstream) |
28 | 0% | 37% | 9% | 13% | 18% | 23% | |
| 25). Parkway (upstream - Walker Branch) | 30 Bacteriodes: Negative | 0% | 39% | 13% | 9% | 21% | 18% | |
| 26). Paint Branch (downstream) | 35 | 0% | 42% | 14% | 15% | 6% | 14% | 9% |
| 27). Sligo Creek (upstream) | 38 Bacteriodes: Negative | 0% | 39% | 11% | 9% | 21% | 20% | |
| 28). Muddy Branch (downstream) | 40 | 0% | 43% | 10% | 9% | 21% | 17% | |
| 29). Little Falls (downstream) | 43 | 0% | 29% | 11% | 13% | 24% | 23% | |
| 30). Lower Anacostia (downstream) | 53 | 0% | 47% | 8% | 12% | 19% | 14% | |
| 31). Piscataway (downstream) | 58 | 0% | 46% | 10% | 14% | 19% | 11% | |
| 32). Rock Creek (downstream) |
60 | 0% | 39% | 7% | 15% | 22% | 17% | |
| 33). Oxon Run (upstream-Watts Branch) | 70 Bacteriodes: Negative | 0% | 46% | 10% | 11% | 27% | 6% | |
| 34). Cabin John Creek (downstream) | 90 (88) Bacteriodes: Negative | 0% (0%) | 41% (42%) | 5% (5%) | 15% (13%) | 23% (24%) | 16% (16%) | |
| 35). Parkway (downstream - Bear Branch) | 93 Bacteriodes: Negative | 5% | 45% | 12% | 12% | 19% | 7% | |
| 36). Lower Beaverdam Creek (downstream) | 148 Bacteriodes: Positive | 7% | 37% | 12% | 8% | 21% | 15% | |
| 37). Oxon Run (downstream) |
243 (315) Bacteriodes: Negative (Negative) | 0% (0%) | 44% (41%) | 14% (13%) | 9% (12%) | 20% (19%) | 13% (15%) | |
| 38). Horsepen (downstream) | 275 Bacteriodes: Positive | 16% | 32% | 7% | 11% | 12% | 13% | 9% |
| 39). Sligo Creek (downstream) | 825 Bacteriodes: Negative | 7% | 33% | 9% | 14% | 19% | 18% | |
| 40). Lower Beaverdam Creek (upstream) | 1025 Bacteriodes: Positive | 13% | 34% | 17% | 11% | 17% | 8% | |
Note from the report:
OTHER MATTERS TO BE BROUGHT TO THE ATTENTION OF EPA, MDE AND THE CITIZENS GROUPS:
As indicated in the text under Article Two, B.5- Water Quality Monitoring (WQM) Plan, under the Polymerase Chain Reaction (PCR) testing protocol for the approved WQM Plan, human source bacteria were identified in one or more samples from four sewer basins. In light of the rapid evolution of Bacterial Source Tracking (BST) technologies, the WQM Plan recommends a periodic re-evaluation of the results of the PCR testing protocol and the methodologies being used. The Virginia Tech laboratory that provides the BST testing services, and which is at the forefront of BST methods development, has recently noted that the current library-based PCR testing protocol may, from time to time, result in false positives where reported human percentage allocations are below 10%. In order to ensure that WSSC receives and presents the most accurate analysis of the presence of human source bacteria, the Virginia Tech laboratory performed additional library-independent human Bacteroides gene testing on a subset of the March 2011 samples. This additional testing revealed false positives in two of the basins sampled, Parkway and Sligo Creek, where the reported percentage allocations were 5% and 7%, respectively. Consequently, application of this additional testing for the Second Quarter of 2011 leads to the conclusion that human source bacteria were identified in one or more samples from only two sewer basins.