Boyer River IA 06-BOY-1510
from confluence with Lime Cr. (SE 1/4 S22 T86N R37W Sac Co.) to confluence with unnamed tributary approximately 5 miles south of Early in S 1/2 S33 T88N R37W Sac Co.
- Cycle
- 2018
- Release Status
- Final
- Overall IR
- 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
- Trend
- Unknown
- Created
- 5/16/2019 1:40:00 PM
- Updated
- 7/30/2019 12:35:57 PM
The Class B(WW1) aquatic life uses remain assessed as "fully supported" based on biological data collected in 2005 as part of the DNR/SHL stream REMAP project. The presumptive Class A1 (primary contact recreation) and Class HH (human health/fish consumption) uses remain "not assessed" due to the lack of data upon which to base an assessment.
The Class B(WW1) aquatic life uses remain assessed (evaluated) as “fully supporting" based on biological data collected in 2005 as part of the DNR/SHL stream REMAP project. A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biological sampling data. The biological metrics are based on the numbers and types of benthic macroinvertebrate taxa and fish species collected in the stream sampling reach. The biological metrics were combined to make a fish community index of biotic integrity (FIBI) and a benthic macroinvertebrate index (BMIBI). The indexes rank the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum). The 2005 FIBI score was 39 (fair) and the BMIBI score was 65 (good). The aquatic life use support was assessed as fully supported (=FS), based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established for previous Section 305(b) reports. The FIBI BIC for this ecoregion is 43 and the BMIBI BIC for this ecoregion is 54. The site met the FIBI BIC with the aid of the UAV of 7 points and also passed the BMIBI BIC in 2005. The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2008. This aquatic life assessment is considered "evaluated" because there were not two or more samples collected from this segment in multiple years over a five-year period. Additionally, because these data are now considered too old (greater than five years) to accurately characterize current water quality conditions, the assessment category is considered “evaluated” (indicating an assessment with relatively lower confidence) as opposed to "monitored" (indicating an assessment with relatively higher confidence). Despite this change in assessment type, this waterbody remains in IR Category 2a.