). The City performed additional coliform analysis at up to 6 stream sites during the summer of 2001. Samples collected by the Jamestown S'Klallam Tribe (from sampling sites identified with the letter "T") were analyzed for temperature and fecal coliform bacteria. The Tribe also measured streamflow at sampling Site T2 during many of sampling events. Samples collected by Clallam County Streamkeepers (from sampling sites identified with the prefix "SK") were analyzed for dissolved oxygen, fecal coliform, nitrate, pH, specific conductivity, temperature, and turbidity. Streamkeepers also measured creek discharge during most of the sampling events. Note that sampling locations on
Samples collected by City were analyzed at their Treatment Plant laboratory, which is certified for BOD, TSS, pH, turbidity, and ammonia. However, laboratory operators report that many of the ammonia measurements are inaccurate due to analytical interference with iron present in the water samples. Samples analyzed by Lauchs Laboratories (Seattle, WA) for ammonia typically showed lower concentrations than those analyzed at the City's lab. Analyses for nitrate and total phosphorus were conducted on a Hach spectrophotometer and should be considered approximate until further instrument calibration is performed. Analytical procedures associated with the water quality data reported by Streamkeepers and the S'Klallam Tribe are unknown.
While all of the monitoring data is valuable for a variety of reasons, some parameters are more diagnostic than others for detecting the influence of streamflow augmentation with reclaimed water, particularly if a particular constituent is known to occur in the reclaimed water. Based on comparison of background water quality in Bell Creek and reclaimed water, nitrate, dissolved oxygen, total phosphorus, and temperature are most likely to show trends related to the streamflow augmentation (ammonia is not included in this list due to laboratory inaccuracies). In addition, while fecal coliform is not detectable in the effluent, it is good indicator of the quality of aquatic habitat. Results for fecal analyses are also discussed herein. Figure 21, Figure 22, Figure 23, and Figure 24 present time-series plots for these parameters, distinguished by station and station location (upstream vs. downstream of the streamflow augmentation point). Visual inspection of these plots was used to evaluate trends over time and between upstream and downstream locations
Dissolved Oxygen and Temperature
WAC 173-201A contains surface water quality standards for both DO and temperature. The standards vary by stream quality classification. Standards for Class AA streams are temperature not exceeding 16oC. and DO not less than 9.5 mg/l.
Dissolved oxygen concentration (DO) in water is inversely related to temperature because the solubility of oxygen is higher in colder waters. Based on this relationship, analytical results for these two parameters are presented for comparison on Figure 21 and Figure 22. Annual cycles of water temperature and dissolved oxygen fluctuations are apparent in both figures, but are more obvious on the expanded time scale used for Figure 21.
Temperature sampling data are sparse prior to the fall of 2000 (Figure 21). The available data suggest that Class AA standards were rarely exceeded during that time period. However, more extensive sampling during late 2000 and 2001 show that temperatures exceeded Class A standards during the summer months (2001). A closer look at the latter data (Figure 22) reveals that temperatures downstream of the augmentation site tended to exceed those upstream during spring and summer but not during fall and winter. This observation applies both before and after testing of the augmentation system began in August 2001. Because the samples are collected during daylight hours, the data may reflect a warming effect in the ponds between the upstream and downstream stations. That is, the warm seasons' sun and warmer air will heat the water throughout the creek, but more so in the ponds at Carrie Blake Park where more surface area will proportionately gain more heat. This may partly explain why downstream temperatures tend to be higher.
DO measurements tended to fall below the Class AA surface-water standard of 9.5 mg/l during summer and autumn months, both before and after streamflow augmentation began (Figure 21 and Figure 22). Similar to temperature data, DO data are relatively sparse prior to the fall of 2000. During 1998, when data are particularly sparse, DO concentrations downstream of Carrie Blake Park tended to exceed upstream concentrations. From early 1999 through winter 2002, this relationship generally reversed, with upstream concentrations exceeding those downstream. Because the latter relationship developed before testing of the streamflow augmentation system began, it is difficult to pick out any effect of the augmentation. Due to the sparsity of data, more sampling will be required to resolve the influences upstream and downstream of the augmentation.
Ammonia
The ammonia standards under WAC 173-201A are for chronic and acute toxicity, with the latter being higher. The standards are not fixed and must be calculated for each sample from pH, temperature, and the ammonia concentration. PGG reviewed ammonia data collected by the City from late 1997 to present, and evaluated the laboratory measurements by Laucks Labs and those made by the City (without apparent interference from iron) relative to standards for acute toxicity. About 25 admissible ammonia measurements showed a range from "non-detect" to 0.03 mg/l; of which only one sample exceeded acute toxicity standard. The remaining 26 measurements were inadmissible due to iron interference, and showed erroneous ammonia values as much as ten times larger than the admissible measurements. Because admissible measurements are available only before streamflow augmentation began, comparison of upstream vs. downstream concentrations cannot be performed. The City is currently modifying its analytical methods to correct the iron interference problem. Evaluation of future data will be required to assess whether water-quality impacts from streamflow augmentation occur.
Nitrate
Nitrate has no surface water quality standard in WAC 173-201A. However, it can be an indicator of contamination. The available nitrate measurements performed by the City's lab should be considered approximate due to the method of analysis (discussed above). All the values shown in Figure 23 are very low and do not indicate contamination. No increase over time or downstream increases are consistently indicated. Although nitrate concentrations in the reclaimed water are typically less than 2 mg/l and rarely exceed the 10 mg/l, they are about 10-times higher than background concentrations in Bell Creek. Only two nitrate measurements are available since testing of the augmentation system began. These two measurements show no significant difference between upstream and downstream sampling locations; however, the data are too sparse to support definitive conclusions.
Phosphorus
Phosphorus also has no surface water quality standard in WAC 173-201A. However, values exceeding a few tenths mg/l probably indicate some form of contamination. Common sources include manure from livestock, other mammals and native birds. Cows in upper Bell Creek were reported on one of the S'Klallam Tribe's sampling notes, and the occurrence of cattle near the creek may not be uncommon. Failing septic systems could be another possible source of phosphorous if septic effluent flows directly into the steam without filtering through the soil. Phosphorous may be a useful indicator of effects from the augmentation water, because the reclaimed water has significantly higher concentrations than background water quality in Bell Creek.
The available phosphorus measurements performed by the City's lab should be considered approximate due to the method of analysis (discussed above). However, the graph of phosphorus over time (Figure 23) shows a minor increasing trend at both upstream and downstream stations increase, with no significant difference between upstream and downstream since augmentation began. Only two sampling events occurred since testing of the augmentation system began. The limited data do not indicate any water quality degradation from the City's augmentation program, and are too sparse and approximate for more definitive analysis.
Fecal Coliform
Fecal coliform standards vary according to stream classification, as with DO and temperature. As a Class A stream, Bell Creek has a standard of 100 colonies per 100 ml with some allowance for occasional exceedences. As shown in Figure 24, the standard frequently is exceeded both upstream and downstream. The reclaimed augmentation water contains no fecal coliform, and therefore cannot be a source to Bell Creek.
11Analysis of effluent quality relative to conditions of the City's NPDES permit for streamflow augmentation is performed regularly by the City as a requirement of their permit. NPDES data analyses are not addressed in this report. Return
12The field sampling program includes 9 sites, of which stream stage is measured at sites 1 through 6, and reclaimed water temperature and DO is measured at Sites 7 through 9. Return
13Laboratory analysis is also performed on treated water at the reclamation facility. Return
