Dissolved Oxygen Concentrations
Dissolved Oxygen Percent Saturation
Average Dissolved Oxygen as Percent Saturation
Average pH and Alkalinity for All Sites
SUMMARY OF PRELIMINARY ANALYSIS OF DATA COLLECTED BY VOLUNTEERS FROM THE SHERMANS CREEK CONSERVATION ASSOCIATION FROM NOVEMBER, 2000 TO MAY, 2001
A total of eight sites have been monitored by volunteers from the Shermans Creek Conservation Association for pH, alkalinity, air temperature, water temperature, oxygen concentration, and nitrate concentration for some portion of the study period from November, 2000 to May, 2001. Six of the sites are located on the mainstem of Shermans Creek; the other two sites are located on forested reaches of two tributaries: Trout Run and Shaeffer Run. All sites are located in the downstream half of the watershed, with the exception of the Shaeffer Run site. The site at Shaeffer Run has been monitored for pH and alkalinity on a weekly basis since November, 1993 and therefore has one of the largest databases on these parameters of any stream in the state. All sites are being currently monitored, with the exception of Sites SC 10.91 and SC 12.90, which were only monitored through February.
Recommendations on study design:
(1) All sites need to be monitored for at least one full year to accurately assess their condition; we therefore recommend continuing the monitoring of the active sites.
(2) As the monitoring program expands, we would recommend focusing on locating sites in tributaries, in particular at locations that are likely to be impacted by agricultural activity or by acid deposition.
(3) In addition, the group should continue its efforts to find volunteers in the upper watershed.
The data contain no water quality violations with the exception of alkalinity concentrations in the two forested tributaries, sites TR 0.32 and SR 5.36. Although concentrations of alkalinity at those sites drop below 20 mg/l, to consider these violations of water quality criteria, we would need to demonstrate that this is not due to natural conditions.
Dissolved oxygen concentrations are inversely proportional to water temperature, as expected in natural systems. Average dissolved oxygen concentrations are well above water quality criteria (must be greater than 5 mg/l or 6 mg/l, depending on the designated use), with a range of 10.014.2 mg/l at the sites monitored. Percent saturation of dissolved oxygen measurements are very high, with averages ranging from 95.0% to 131.8%. High percent saturation occurs at the most downstream site and should be carefully monitored to determine if eutrophication is impacting this reach.
Average nitrate concentrations are well below the water quality criteria of 10 mg/l (NO3+NO2). The lowest nitrate concentrations are in the Shaeffer Run tributary. Nitrate concentrations at the Trout Run tributary was only measured once, resulting in one of the highest nitrate concentrations (1.00 mg/l); this site needs to be monitored for nitrates on a monthly basis. At SC 20.62, nitrate concentrations were determined to be 5 mg/l in November, 2000. This site should be monitored carefully to see if this kind of elevation occurs again. Including this data point, average nitrate concentrations at the sites vary from 0.23 mg/l to 1.89 mg/l. Although it is too early to firmly document patterns, these initial data show slightly higher nitrate concentrations at sites upstream from SC 12.90 than at sites downstream from this site.
Average pH and alkalinity concentrations on the mainstem sites are well within water quality criteria, with average pH ranging from 6.13 to 7.30 and average alkalinity ranging from 45.79 mg/l to 74.59 mg/l. These concentrations indicate a well-buffered system and reflect, in part, the underlying limestone geology in some areas of the watershed.
However, the two tributaries (Trout Run and Shaeffer Run) have average pH and alkalinity concentrations that exceed water quality criteria, with average pH being 5.00 and 5.59 and average alkalinity being 8.69 mg/l and 1.51 mg/l, respectively. Water quality criteria require pH to be between 6.0 and 9.0 and alkalinity concentrations to be above 20 mg/l, except where natural conditions are less.
Both Trout Run and Shaeffer Run are forested tributaries, originating at high elevations and contained within watersheds with no underlying limestone. Natural conditions and/or acidic deposition may be the cause of the acidic conditions reflected in the monitoring data. The station at Shaeffer Run has been monitored on a weekly basis for pH and alkalinity since November, 1993 and shows a stream that is endangered, with little acid neutralizing capacity, seasonal fluctuations of alkalinity, and an inability to resist any further acidic input. Consistently low alkalinity concentrations since March, 2000 may indicate that Shaeffer Run has lost its buffering capacity.
Dissolved Oxygen Concentrations
Dissolved Oxygen Percent Saturation
Average Dissolved Oxygen as Percent Saturation
Average Nitrate Concentrations