Yellow Smoke Park Lake IA 06-BOY-1514

For the 2016 assessment/listing cycle, the Class A1 (primary contact recreation) uses of Yellow Smoke Park Lake are assessed (monitored) as "fully supported" based on information from the ISU lake survey. Using the median values from these surveys from 2010-2014 (approximately 15 samples), Carlson 's (1977) trophic state indices for Secchi depth, chlorophyll a, and total phosphorus were 46, 51, and 49 respectively for Yellow Smoke Park Lake. According to Carlson (1977) the Secchi depth, chlorophyll a, and total phosphorus values all place Yellow Smoke Park Lake in between the Mesotrophic and the Eutrophic categories. These values suggest low levels of chlorophyll a and suspended algae in the water, exceptional water transparency, and extremely low levels of phosphorus in the water column. The data show no violations of the Class A1 criterion for pH in 15 samples.

The level of inorganic suspended solids was extremely low at Yellow Smoke Park Lake, and does not suggest water quality problems due to non-algal turbidity. The median level of inorganic suspended solids in Yellow Smoke Park Lake (1.6 mg/L) was ranked 2nd among the 138 lakes by the ISU lake survey.

Data from the 2010-2014 ISU lake survey suggest a small population of cyanobacteria exists at Yellow Smoke Park Lake. These data show that cyanobacteria comprised 60% of the phytoplankton wet mass at this lake. The median cyanobacteria wet mass (5.3 mg/L) was ranked 14th of the 138 lakes sampled.

The Class B(LW) (aquatic life) uses are assessed (monitored) as "fully supported." Results of the ISU lake survey from 2010-2014 show there were no violations of the criterion for ammonia in 15 samples(0%), no violations of the criterion for dissolved oxygen in 15 samples(0%), and no violations of the criterion for pH in 15 samples(0%). Based on IDNR's assessment methodology these violations are not significantly greater than 10% of the samples and therefore suggest (fully supported/monitored) of the Class B(LW) uses of Yellow Smoke Park Lake.

The Class B(LW) (aquatic life) uses are now assessed (evaluated) as “fully supported.” Information from the IDNR Fisheries Bureau indicates that the previous impairment due to siltation in the upper arm of this lake was been addressed and corrected.   According to IDNR Fisheries, over the last 10 years, the Crawford County Conservation Board was a awarded a fish habitat grant to rectify the siltation problem at Yellow Smoke Lake.   As a result, silt was removed from the upper end of the lake via backhoe, the shoreline was armored in the upper end, a partial sediment trap/basin was installed in the very upper end of the lake, and an additional sediment pond was constructed on private property further up in the lake’s watershed.  Also, pea gravel/sand bed was placed in the north arm of the lake to create bluegill spawning habitat.   A 2010 fish survey shows that the fish populations at this lake are well balanced, healthy, and that natural reproduction is occurring on a consistent basis.  

The assessment of support of the fish consumption uses is changed from “partially supported” (impaired) to "fully supporting" based on results of U.S.  EPA/IDNR fish contaminant monitoring in 2012 and 2014.   The existence of, or potential for, a fish consumption advisory is the basis for Section 305(b) assessments of support of fish consumption uses in Iowa’s rivers and lakes.  The fish contaminant data generated from the 2011 RAFT sampling conducted at Yellow Smoke Lake showed that levels of mercury are sufficiently high for concern and thus justified issuance of a one meal/week fish consumption advisory in 2013.  Results from the 2011 sampling showed that the average level of mercury in the sample of largemouth bass muscle tissue (0.7 ppm) far exceeded the 1 meal/week trigger level (0.30 ppm) as defined in Iowa’s revised (2007) fish consumption advisory protocol.  According to the Iowa DNR/Iowa Dept.  of Public Health fish advisory protocol, the single occurrence of contaminant above an advisory trigger level does not typically result in issuance of an advisory.  Such an advisory is issued only after follow-up monitoring confirms that contaminant levels exceed the advisory trigger level.  Becasue, however, the average level of mercury was nearing the "do not eat" advisory threshold  of 1.0 ppm, Iowa DNR issued the one-meal/week consumption advisory without the need for a follow-up/confirmation sampling.   Follow up monitoring was conducted in 2012 on largemouth bass.  The average level of mercury in the tissue plug samples from five largemouth bass was 0.218 ppm (SD=0.074 ppm; maximum=0.331 ppm) and was below Iowa's advisory threshold of 0.3 ppm.   According to Iowa DNR assessment/listing guidelines, however, two consecutive samples showing average contaminant levels below the advisory threshold are needed before an advisory can be rescinded.   The average level of mercury in the next (2014) sample of five largemouth bass from Yellow Smoke was 0.194 ppm (SD=0.093 ppm; Max.  = 0.29 ppm).   Similar to the results from the 2012 sampling, the 2014 average level of mercury was below the consumption advisory threshold of 0.3 ppm.    Because the the 2014 sample was the second consecutive sampling that showed that average levels of mercury are below the advisory threshold, the fish consumption impairment due to mercury was proposed for delisting durring the 2014 IR.

U.S.  EPA/IDNR contaminant (RAFT) monitoring at Yellow Smoke Lake in 2009 showed that levels of contaminant in turtle tissue were below Iowa's consumption advisory thresholds.  The composite samples of shoulder tissue from snapping turtle had low levels of contaminants.  Levels of primary contaminants in the shoulder tissue of snapping turtle were as follows: mercury: 0.122 ppm; total PCBs: 0.09 ppm; and technical chlordane: <0.03 ppm.   Thus, the turtle contaminant data generated from the 2009 RAFT sampling show that the levels of contaminants do not exceed any of Iowa's advisory thresholds for a one-meal/week advisory (0.3 ppm for mercury, 0.2 ppm for PCBs, and 0.6 ppm for chlordane).

Note: A TMDL for siltation at Yellow Smoke Lake was prepared by IDNR and approved by EPA in 2002; thus, this waterbody was placed into IR Category 4a (TMDL approved) for the 2004 assessment/listing cycle.  Because all Section 303(d) impairments identified for the 2012 assessment/listing cycle (siltation) were addressed by the TMDL, this waterbody remained in IR Category 4a (TMDL approved) from the 2004 through 2010 assessment/listing cycles.   Due to in-lake and watershed work conducted from 2003 to 2008 correct this impairment, and due to information on condition of the fishery at this lake, the siltation impairment was removed for the 2012 Integrated Reporting cycle.   Thus, the aquatic life uses are considered “fully supported” (IR Category 2a).