Streamwatch Project
Middle Run and Lower Mainstem of White Clay Creek: Site 24
Site 24 on Middle Run is directly upstream of Fox Den Road. The watershed is the second smallest in the study but has the highest density of people based on 2000 census data. Land use is predominantly pastures with a low amount of row crops but a high number of roads (impervious surfaces made up 5% of the watershed, double the amount found at most sites) and low intensity developed land (13%). Water samples were never taken at this site.
This location on Mill Run was only sampled in 2001. Although a large proportion (45%) of the total numbers (≈3500 individuals/m2) were chironomids (≈1600 individuals/m2) there was also an abundance of pollution sensitive taxa such as black flies, riffle beetles, and ephemerellid mayflies (i.e., these three groups made 37% of the total density). The MAIS score was 7.9 (Fair) and similar to scores reported for Site 23, which was located downstream on Middle Run. Conditions on the mainstem of the Lower White Clay Creek are Poor (i.e., in the same year Site 22 had a MAIS score of 2.8), which implies Middle Run is not contributing to this degradation but may actually help enhance conditions on the mainstem.
| Location | |
|---|---|
| Site number | 24 |
| Description | Middle Run upstream of Foxden Road |
| Lat Long (hr min sec) | 39°43.227’ N, -75°43.075’ W |
| Land Use | |
| Watershed area above site (km2) | 4 |
| Population density in 2000 (#/km2) | 468 |
| % Population increase from 1990 to 2000 | 20 |
| Percent pasture/hay | 50 |
| Percent cultivated crops | 12 |
| Percent forest | 13 |
| Chemistry | |
| Nitrate (mg/L) | n/a |
| Ammonium (mg/L) | n/a |
| Total Dissolved Phosphorus (mg/L) | n/a |
| Soluble Reactive Phosphorus (mg/L) | n/a |
| Sulfate (mg/L) | n/a |
| Alkalinity (as mg/L CaCO3) | n/a |
| pH | n/a |
| Conductivity (μmhos) | n/a |
| Dissolved organic carbon (mg/L) | n/a |
| Macroinvertebrate Data | |
| years sampled | 2001 |
| MAIS score | 7.9 |
| water quality based on MAIS score | Fair |
 Click on macroinvertebrate name to view a photo | |
| 1st most abundant macroinvertebrate | Chironomidae (midges) |
| 2nd most abundant macroinvertebrate | Simuliidae (black flies) |
| 3rd most abundant macroinvertebrate | Elmidae (riffle beetles) |
| 4th most abundant macroinvertebrate | Ephemerellidae (spiny crawler mayflies) |
| 5th most abundant macroinvertebrate | Empididae (dance flies) |