Water Quality Division

Blue Thumb Program

Data Interpretation  

Polecat Creek: 33rd West Avenue

Polecat Creek: 33rd West Avenue
SW NW NW
Section 27-18N-12E
Tulsa County
Lattitude N 36° 00’ 54.5”
Longitude W 96° 01’ 45”
WBID#: OK120420-02-0050G

Site description

Polecat Creek is located in the Cross Timbers ecoregion in northeast Oklahoma. As a 5th order stream, it is among the largest streams monitored by Oklahoma’s Blue Thumb Program. Its watershed covers over 200 square miles. Its headwater starts between the towns of Drumright and Oilton in Creek County. From there it trends east and goes through Heyburn Reservoir, Sapulpa and eventually drains into the Arkansas River. Land use in the watershed is agricultural, urban, and industrial with some of Oklahoma’s oldest oil fields along its banks. The effluent from several communities drains into Polecat Creek. Blue Thumb volunteers monitor the stream monthly at 33rd West Avenue south of 101st Street in Tulsa County.

Polecat Creek is deeply incised at the monitoring site under the bridge at 33rd West Avenue. To get down into the site, one must walk down a steep, rock-covered hill through thick brush and small trees. The stream itself is rocky and often has scattered trash items in it. There is a topsoil mining company on the north bank of the stream. The lack of ground cover in the mining area seems to cause heavy erosion on the north side of the stream bank. There is also a commercial dump just to the southwest of the site.

Habitat assessment

Two habitat assessments have been conducted, one in 1996 and the other in 2001. The results of a 2006 assessment are pending. Overall, the habitat assessment shows that the stream habitat is in moderate condition when compared with the average of high quality reference streams in the ecoregion. Because of its size, Polecat Creek always has water, even during the recent drought. There is good high quality cover for organisms to hide behind, though some of it is trash that has been dumped from the bridge. Average water depth is 0.67 meters; the maximum depth is 2.5 m. About 80% of the stream is pooled. There is not much canopy cover to shade the water. Soil mining activities on the north bank of the stream have reduced the amount of streamside vegetation and contributed to some sedimentation. Polecat Creek is fairly straight in this reach.

Aquatic life collections

There have been two fish collections in the past ten years. The state of health is measured by comparing Polecat Creek with reference conditions for the Cross Timbers ecoregion, which is the average of high quality streams in the ecoregion. The total metric score for reference conditions for fish is 22.
The fish collection made 10/15/1996 had 21 species of fish which included seven species of sunfish (green sunfish, orangespotted sunfish, longear sunfish, redear sunfish, spotted bass, largemouth bass and white crappie.) There were two intolerant species, the suckermouth minnow and the slim minnow. The biggest difference between this collection and reference conditions is the absence of sensitive benthic species like darters. The 1996 fish collection receives a total metric score of 18 which is 82% as good as reference conditions. This scores a “B” on the Index of Biotic Integrity (IBI), indicating decreased species richness, mostly the intolerant species.

The fish collection made 6/27/2001 had 20 species of fish which also included seven species of sunfish (bluegill sunfish, longear sunfish, redear sunfish, spotted bass, largemouth bass and white crappie.) There was only one intolerant species, the suckermouth minnow, though there was one species of darter (slenderhead darter.) The total metric score in 2001 is 16; 73% as good as reference conditions. This collection scores a “C” on the Index of Biotic Integrity (IBI), indicating that intolerant and sensitive species are rare or absent.

Macroinvertebrates have been collected every winter in January/February and every summer in July/August. Summer collections in the last five years have an average number of 11 taxa compared with 20 taxa in reference conditions. This indicates reduced water and/or habitat quality. There were three Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa in Polecat Creek compared with 7 taxa in reference conditions. The EPT taxa are the mayflies, stoneflies, and caddisflies that are more sensitive to pollution than any other groups. A single taxon, Trichoptera Cheumatopsyche, made up 53% of the individuals collected in the samples. Species diversity is limited. As more and more species are excluded by increasing pollution, the remaining species can increase in numbers due to the unused resources left by the excluded animals. The summer riffle metric score at Polecat Creek is 44% of reference conditions for the Cross Timbers ecoregion, earning an IBI score of “C”.

Winter macroinvertebrate collections in the last five years have an average number of 13 taxa compared with 16 taxa in reference conditions. Once again the EPT taxa were limited and the dominant taxon was 46% of the sample. The winter metric score at Polecat Creek is 69% of reference conditions, earning an IBI score of “B”.

Bacteria

Eschericia coli has been measured during the summer months of May through September. For streams where people wade and play the E. coli level should be below 400 CFU/100 ml. The highest values each year were measured in May and June. All of the results above 400 CFU/100 ml are listed below:

5/26/1999 690 CFU/100 ml
6/24/1999 >2400 CFU/100 ml
6/29/2000 >2400 CFU/100 ml
7/27/2000 460 CFU/100 ml
5/31/2001 2000 CFU/100 ml
6/28/2001 1700 CFU/100 ml
6/26/2003 >2400 CFU/100 ml
6/24/2004 950 CFU/100 ml
8/25/2005 825 CFU/100 ml

Chemical Quality

The chemical data show that Polecat Creek usually has a healthy amount of dissolved oxygen in the water. The percent oxygen saturation dropped to 29% on 12/29/2001, the only time it was below 50% saturation. There have been eight times since 7/28/2001 when the percent oxygen saturation was between 50% and 80%.

pH has stayed between 7.5 and 8.0, which is healthy.

An estimate of soluble nitrogen is made by adding the amounts of ammonia-nitrogen and nitrate-nitrogen found in the water. A healthy stream should have less than 0.8 mg/L N. Polecat Creek exceeded this level:

on 7/27/2002 with 1.16 mg/L N,
on 12/31/2004 with 0.88 mg/L N,
on 11/4/2005 with 1.0 mg/L N,
on 11/26/2005 with 2.0 mg/L N, and
on 12/24/2005 with 1.0 mg/L N.

These are not dangerous amounts, but will support algae growth.
Orthophosphate. phosphorus is another nutrient found occasionally in Polecat Creek. A healthy stream should have less than 0.1 mg/L P. Levels found have exceeded this level: 

on 12/1/2001 with 0.1 mg/L P,
on 12/28/2002 with 0.107 mg/L P,
on11/31/2002 with 0.120 mg/L P,
on12/28/2002 with 0.5 mg/L P,
on1/26/2003 with 0.167 mg/L P,
on 6/28/2003 with 1.433 mg/L P,
on 11/29/2003 with 0.137 mg/L P,
on 6/26/2004 with 0.163 mg/L P,
on 10/30/2004 with 0.2 mg/L P,
on 8/27/2005 with 0.190 mg/L P,
on 9/24/2005 with 0.240 mg/L P,
on 11/14/2005 with 0.173 mg/L P,
on 11/26/2005 with 0.170 mg/L P,
on 12/24/2005 with 0.1 mg/L P,
on 2/8/2006 with 0.133 mg/L P, and
on 4/11/2006 with 0.107 mg/L P.

Chloride presence is less than 200 mg/L, which is a safe level.

Synopsis

Monitoring Polecat Creek monthly provides information about the health of a large and important watershed. The habitat is quite good, especially considering the soil mining and dump on the banks at the site. Biological collections indicate a loss of some of the most sensitive species of fish and macroinvertebrates. Overall, the creek remains fairly healthy. It faced challenges in the past from effluent released by Sapulpa’s water treatment plant. Fortunately, the plant has been modernized in recent years and the effluent released has been kept to a minimum. Through continued monitoring, problems can be addressed before they become serious. Under the watchful eyes of volunteers, the life supported by Polecat Creek and its watershed will continue to be protected.