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| Title | Lower Okanogan River Basin DDT and PCB Total Maximum Daily Load: Water Quality Effectiveness Monitoring Report | |||
| Month-Year Published | May 2011 | |||
| Online Availability |
1284 kilobytes, requires version 4.0 or later of Adobe Acrobat Reader Software get Acrobat Reader
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| Short Description |
DDT and PCB concentrations in composite fish tissue samples collected from the Lower Okanogan River in 2001 were compared against a similar data set collected in 2008. Three species were sampled: smallmouth bass (Micropterus dolomieui), mountain whitefish (Prosopium williamsoni), and common carp (Cyprinus carpio). The number of samples not meeting (exceeding) National Toxics Rule criteria was similar between the 2001 and 2008 studies. No carp specimens were obtained from the lower reach in 2001 due to unavailability. However, large specimens of carp collected from this reach in 2008 had elevated concentrations of total DDT. (Also see abstract below) | |||
| Publication Number | 11-03-009 | |||
| Author(s) | Newell, E | |||
| Print Availability | ||||
| Number of pages | 54 + app (79 total) | |||
| Keywords | basin, DDT, fish, monitoring, Okanogan River, Total Maximum Daily Load, toxic, water quality, WRIA 49 | |||
| Subject Waterbodies |
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| Related Publications | Title | Relationship | ||
| Lower Okanogan DDT PCB Detailed Implementation Plan: Water Quality Implementation Plan | related publication | |||
| Quality Assurance Project Plan: Okanogan River DDT and PCB Total Maximum Daily Load Effectiveness Monitoring | supporting publication | |||
| Abstract | Long Description |
This study monitors the effectiveness of the Lower Okanogan River Total Maximum Daily Load (TMDL) for the legacy contaminants DDT and PCB. The study compares contaminant concentrations in composite fish tissue samples collected in 2001 against a similar data set collected in 2008. Three species were sampled: smallmouth bass (Micropterus dolomieui), mountain whitefish (Prosopium williamsoni) and common carp (Cyprinus carpio). Samples were collected from three reaches of the Okanogan River along a span of 79 river miles. The number of samples not meeting (exceeding) National Toxics Rule criteria is similar between the 2001 and 2008 studies. No carp specimens were obtained from the lower reach in 2001 due to unavailability. However, large specimens of carp collected from this reach in 2008 had elevated concentrations of total DDT. A fish consumption advisory for carp is likely to be issued by the Washington State Department of Health based, in part, on these 2008 samples. Comparability between the two studies was difficult due to small sample size. No significant changes were found in median total DDT concentrations between the two studies. A decrease in lipid-normalized median total PCB concentration was found for common carp, significant at the 90% level. No other significant changes were found in median total PCB concentrations. Mountain whitefish from the lower reach show slightly lower levels of contamination than in the other two reaches. Otherwise, overall contamination in fish is similar among the three reaches. As a result of this study, the Department of Ecology recommends:
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This page last updated August 17, 2011
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