Mississippi River IA 01-NEM-62

The Class A (primary contact recreation) uses are assessed as “partially supported” based on the impairment of primary contact recreation uses identified for this segment of the Upper Mississippi River by the Illinois EPA for the 2016 Section 303(d) listing cycle. The Illinois EPA identified an impairment of primary contact recreation uses in this river segment due to high levels of indicator bacteria (fecal coliforms). This assessment was developed as a result of interstate consultation on Section 303(d) listing conducted through the Upper Mississippi River Basin Association’s “Water Quality Task Force” in June 2016.

Results of conventional chemical/physical water quality monitoring based on results of Illinois EPA monitoring at station M-02 near Rock Island, IL suggest “full support” of the aquatic life uses. Monitoring showed no violations of Class B(WW1) water quality criteria for 18 Ammonia samples (maximum = 0.4 mg/L), 17 Dissolved Oxygen samples (minimum = 5.4 mg/L), 19 pH samples (range = 7.1 to 8.7), 19 Temperature samples (maximum = 26.6°C), 20 Chloride samples (maximum = 535 mg/L), or 19 Sulfate samples (maximum = 69 mg/L) occurred during monitoring from February 2014 to December 2016.According to U.S. EPA guidelines for Section 305(b) water quality assessments (U.S. EPA 1997b, page 3-17), the EPA guidelines allow up to 10% violations of these conventional parameters before impairment of water quality is indicated. Thus, these results thus suggest “full support” of the Class B(WW1) aquatic life uses.

Addintionally, Monitoringfor additional toxic polutants showed no violations of Class B(WW1) chronic water quality criteria for 20 Arsenic samples (maximum = 2.83 ug/L), 20 Cadmium samples (maximum = 1.5 ug/L), 19 Chromium samples (maximum = 2.5 ug/L), 20 Copper samples (maximum = 2.5 ug/L), 20 Dieldrin samples (maximum = 0 ug/L), 20 Nickel samples (maximum = 2.5 ug/L), 20 Selenium samples (maximum = 2.5 ug/L), 19 Zinc samples (maximum = 30.5 ug/L), 20 p,p'-DDD samples (maximum = 0 ug/L), 20 p,p'-DDT samples (maximum = 0 ug/L), or 20 p,p'-DDE samples (maximum = 0 ug/L) occurred during monitoring from February 2014 to December 2016.

Results of Class HH(human health) monitoring based on results of Illinois EPA monitoring at station M-02 near Rock Island, IL also suggest “full support” of the human health uses. Monitoring showed no violations of Class HH(human health) criteria for 20 Copper samples (maximum = 2.5 ug/L), 9 Cyanide samples (maximum = 10 ug/L), 20 Dieldrin samples (maximum = 0.005 ug/L), 20 Nickel samples (maximum = 2.5 ug/L), 20 Selenium samples (maximum = 2.5 ug/L), 19 Zinc samples (maximum = 30.5 ug/L), 20 p,p'-DDD samples (maximum = 0.005 ug/L), 20 p,p'-DDT samples (maximum = 0.005 ug/L), or 20 p,p'-DDE samples (maximum = 0.005 ug/L) occurred during monitoring from February 2014 to December 2016.2 of the 20 samples (10 %) analyzed for Arsenic (maximum = 2.83 ug/L) violated the Class HH(human health) criteria during the 2014-2016 monitoring period. According to Iowa DNR’s assessment/listing methodology, if the mean level of a toxic metal or pesticide is greater than its respective human health criterion, impairment (“nonsupport”) of the Human Health use is indicated. Because these violations for this parameter is not above their respective MCL's and Class HH(human health) criteria, these results do not suggest impairment of the Class HH(human health) uses.

Fish contaminant monitoring was conducted in this segment of the Mississippi River in September 2012 as part of ongoing studies by ALCOA to update the levels of PCBs in UMR Pool 15 fish (channel catfish and common carp) and to identify any trends in PCB contamination based on periodic monitoring in this Pool over the last 25 years. Sampling was conducted at three locations: Pool 15 near the ALCOA facility, Pool 14 near LeClaire, IA, and Pool 15 on the Illinois side of the river. The LeClaire and Illinois sites were chosen as reference sites. ALCOA used performance standards of 0.226 mg/kg for channel catfish and 0.231 mg/kg for common carp (these performance standards approximate Iowa’s threshold for issuing a one-meal/week consumption advisory). Results showed that levels of PCBs in channel catfish were low at all sample sites and met the performance standard. Levels of PCBs in common carp met performance standards at the LeClaire (Pool 14) and Illinois-side sites, but levels near the ALOCA facility were above the performance standard. It was hypothesized that the larger size of fish collected in Pool 15 near ALCOA was, in part, responsible for the higher levels of PCBs seen. An Iowa DNR review of the 2012 ALCOA data shows that levels of PCBs in the sizes of common carp collected for the Iowa DNR’s fish tissue monitoring program (12-21 inches, total length) were well below Iowa’s advisory threshold for PCBs of 0.2 mg/kg at all sites sampled in 2012. For common carp between 12 and 21 inches in total length, none of the PCB levels in fish from any of the ALCOA sites sampled exceeded 0.1 mg/kg (i.e., half the Iowa consumption advisory trigger). PCB levels tended to exceed the Iowa advisory trigger in fish greater than 24 inches in total length (the largest common carp analyzed was nearly 30 inches in total length). None of the PCB levels seen in the larger common carp, however, exceeded Iowa’s “do not eat” advisory threshold of 2.0 mg/kg: the maximum PCB concentration was 0.715 mg/kg of total PCBs. Based on the low levels of PCBs in samples of channel catfish from all study locations, (2) low levels of PCBs in common carp from all sites except near the ALCOA facility, and (3) low levels of PCBs in common carp of sizes that meet EPA/Iowa DNR fish tissue monitoring guidelines, the human health/fish consumption uses of this assessment segment are assessed as “fully supported”.

Based on results of the 2012 ALCOA study, however, follow-up fish tissue monitoring was conducted in UMR Pool 15 in 2013 and 2014 as part of Iowa DNR’s fish tissue monitoring program. In the 2013 sampling, the average levels of mercury in tissue plugs from three largemouth bass was 0.24 ppm; this level is below the Iowa threshold of 0.3 ppm for a one-meal/week consumption advisory. The level of PCBs in the composite sample of fillets from five Common Carp was reported as < 0.6 ppm. This unusually high non-detect level, which is three time higher than Iowa’s threshold for a one-meal/week consumption advisory, was due to laboratory method detection levels of 0.2 ppm for each of the three Aroclors (1248, 1254, and 1260) analyzed to determine “total PCBs”. Thus, results of follow-up monitoring for PCBs in Common Carp in this river segment were inconclusive.

Due to problems with analysis of the 2013 fish tissue samples for PCBs, monitoring was again conducted in this river segment in 2014. A status sampling to determine levels of mercury in predator fish species and bottom-feeder sampling was conducted. The average level of mercury in the tissue plugs from five white bass was 0.186 ppm which is below the 0.3 ppm consumption advisory threshold. The level of total PCBs in the composite sample of fillets from the Common Carp was <0.06 ppm (lower detection levels for Aroclors were used for the 2014 samples (0.02 ppm) compared to the detection levels used for the 2013 samples (0.2 ppm)). This level of PCBs is well below the consumption advisory threshold of 0.2 ppm. Due, however, to the high level of total PCBs seen in ALCOA’s 2012 sample of large Common Carp from 24 to 30 inches in total length, the 2014 Iowa DNR sampling included collection of an additional composite sample of fillets from three Common Carp that averaged 26.7 inches in total length. By design, this fish in this composite sample were much larger (longer) than the upper length limit of 21 inches used for routine Iowa DNR fish contaminant monitoring. The level of total PCBs in the 2014 composite sample of large Common Carp was 0.42 ppm which is approximately two-times higher than the one-meal/week consumption advisory threshold. The only Aroclor detected was 1254 at 0.38 ppm; the other two Aroclors (1248 and 1260) were reported as less than the detection level of 0.02 ppm. Based on this confirmation sampling, a one meal per week consumption advisory for large Common Carp (> 20 inches) was issued by Iowa DNR and Iowa DPH.

Follow up monitoring in 2015 and 2016 showed decreased levels. The level of mercury in the sample of 2016 composite sample white bass fillets was 0.186 ppm which is less than the DNR/DPH advisory trigger level of 0.3 ppm for a one meal per week advisory. The levels of technical chlordane in common carp was <0.02 ppb.The levels of totalPCBsin common carp was <0.06 ppb which is well below the advisory threshold.According to Iowa’s consumption advisory protocol, however, two consecutive samplings that show levels of fish contaminants are below the advisory threshold are needed to rescind an existing advisory. Thus, the segment will remain assessed(monitored) as "partially supported” (IR Category 5a) due to high levels of PCBs in fish tissue and issuance of a one meal per week consumption advisory.