Understanding Water Sampling and Putting CLC Sampling into the Appropriate Context
As discussed in the section "Environmental Findings 2011," the results of CLC’s sampling were as follows:
• Bacterial test results were variable depending on location and date of testing. Most, but not all, were below Maximum Contaminant Limits
• Nitrogen test results were comparatively low and typically below detection limits
• Phosphorus test results were generally low with minor elevations above detectable levels in some areas
• Pesticides, herbicides and arsenic were not detected
Sampling done in early August showed detection of phosphorus at two outfall sites (Levingston Cove) and no detection of levels of nitrate at 9 of 10 sites. Bacterial testing found that E.coli counts were below the State EPA requirements of Maximum Contamination Levels (MCL) throughout the lake except at two outfall sites at Levingston Cove. At Levingston Cove, there are three outfalls for storm water pipes that drain into this cove in close proximity. The City has performed some repair work on underground pipes during the summer and subsequent sample readings showed lower bacterial counts at these Levingston Cove sites. Also in early August, Enterococci levels were above MCL at all testing sites in the lake except near a non-draining outfall pipe by the condominiums, where no direct runoff appears to enter the lake. The volunteers gathered samples again in late August, at which time the E. coli counts were below MCL everywhere except at one outfall at Levingston Cove. Enterococci detection continued to be above MCL at two of three outfalls at Levingston Cove, at both Cronin’s Cove outfalls, and at Lakewood Terrace. Cronin’s Cove has two outfall pipes, and Lakewood Terrace has one. Minor levels of phosphorus and nitrate were detected at Cronin’s Cove and phosphorus levels were also detected at the Bathhouse.
Water sampling was conducted at two dates in September. At both times, E. coli levels were below MCL at all sites testing in the lake. On one testing date, Enterococci levels exceeded MCL near the Norwood condominiums and at one outfall at Levingston Cove. Nitrogen, ammonia, and phosphorus were evaluated at one of the September testing dates. Nitrate and ammonia results were undetectable at all testing sites ,whereas phosphorus levels were found to be very slightly above the detection limit at Cronin’s Cove and near the Norwood condominiums. The final sampling of the year occurred in mid October. Testing at that time found E. coli levels to be below MCL throughout the entire lake and Enterococci levels were below MCL at all testing sites except at Lake Terrace, where only a slight increase over MCL was detected.
It is important to recognize that our water sampling program tested areas mostly near storm water drains. Eight out of ten of our testing sites were near these outfall sites. Our volunteers generally took samples of water several feet away from the outfall site and from a depth of approximately 1-2 feet. For the most part, these storm water pipes that flow into Crystal Lake drain water from the streets near the coves. From time to time, animals such as raccoons and others may wander into these drains. Also, it has been noted that bags of dog excrement may find their way into the storm water system.
As required, we collected our samples using gloves in containers that were place on ice and delivered to the lab on the same day as collection. However, the CLC’s water sampling program was not conducted to the standards necessary to evaluate whether swimming is safe or should be allowed at certain areas of the lake. In order to assess water quality for swimming, the sample must be obtained from a part of the lake that is at least 3 feet deep and it should be obtained at a depth 1-2 feet below the surface. Anyone reviewing our data should keep in mind that we collected most of our samples adjacent to storm water outfalls that empty into Crystal Lake. The CLC’s water sampling data should at this point be considered as preliminary and subject to revision and further interpretation.
• Bacterial test results were variable depending on location and date of testing. Most, but not all, were below Maximum Contaminant Limits
• Nitrogen test results were comparatively low and typically below detection limits
• Phosphorus test results were generally low with minor elevations above detectable levels in some areas
• Pesticides, herbicides and arsenic were not detected
Sampling done in early August showed detection of phosphorus at two outfall sites (Levingston Cove) and no detection of levels of nitrate at 9 of 10 sites. Bacterial testing found that E.coli counts were below the State EPA requirements of Maximum Contamination Levels (MCL) throughout the lake except at two outfall sites at Levingston Cove. At Levingston Cove, there are three outfalls for storm water pipes that drain into this cove in close proximity. The City has performed some repair work on underground pipes during the summer and subsequent sample readings showed lower bacterial counts at these Levingston Cove sites. Also in early August, Enterococci levels were above MCL at all testing sites in the lake except near a non-draining outfall pipe by the condominiums, where no direct runoff appears to enter the lake. The volunteers gathered samples again in late August, at which time the E. coli counts were below MCL everywhere except at one outfall at Levingston Cove. Enterococci detection continued to be above MCL at two of three outfalls at Levingston Cove, at both Cronin’s Cove outfalls, and at Lakewood Terrace. Cronin’s Cove has two outfall pipes, and Lakewood Terrace has one. Minor levels of phosphorus and nitrate were detected at Cronin’s Cove and phosphorus levels were also detected at the Bathhouse.
Water sampling was conducted at two dates in September. At both times, E. coli levels were below MCL at all sites testing in the lake. On one testing date, Enterococci levels exceeded MCL near the Norwood condominiums and at one outfall at Levingston Cove. Nitrogen, ammonia, and phosphorus were evaluated at one of the September testing dates. Nitrate and ammonia results were undetectable at all testing sites ,whereas phosphorus levels were found to be very slightly above the detection limit at Cronin’s Cove and near the Norwood condominiums. The final sampling of the year occurred in mid October. Testing at that time found E. coli levels to be below MCL throughout the entire lake and Enterococci levels were below MCL at all testing sites except at Lake Terrace, where only a slight increase over MCL was detected.
It is important to recognize that our water sampling program tested areas mostly near storm water drains. Eight out of ten of our testing sites were near these outfall sites. Our volunteers generally took samples of water several feet away from the outfall site and from a depth of approximately 1-2 feet. For the most part, these storm water pipes that flow into Crystal Lake drain water from the streets near the coves. From time to time, animals such as raccoons and others may wander into these drains. Also, it has been noted that bags of dog excrement may find their way into the storm water system.
As required, we collected our samples using gloves in containers that were place on ice and delivered to the lab on the same day as collection. However, the CLC’s water sampling program was not conducted to the standards necessary to evaluate whether swimming is safe or should be allowed at certain areas of the lake. In order to assess water quality for swimming, the sample must be obtained from a part of the lake that is at least 3 feet deep and it should be obtained at a depth 1-2 feet below the surface. Anyone reviewing our data should keep in mind that we collected most of our samples adjacent to storm water outfalls that empty into Crystal Lake. The CLC’s water sampling data should at this point be considered as preliminary and subject to revision and further interpretation.