Critique of North Branch of Sunrise River TMDL Nate Topie and Taylor Hoffman

Background  East Central MN, tributary of Sunrise River and part of larger St. Croix River Basin  Most of river basin has high or very high aquifer sensitivity to pollution  Land use TypePercentage Agriculture58.1 Forest8.3 Open Water5.3 Forested Wetland17.7 Non-Forested Wetland8.0 Barren0.1

Background Ctd.  Listed as impaired water under 303d of Clean Water Act due to Fecal Coliform  Impaired for swimming & other primary contact recreation  Fecal Coliform: bacteria present in intestines of warm- blooded animals  Indicator for contamination by feces  Indicator for presence of waterborne pathogens, viruses, protozoa

Water Quality Standards  Standard Part 1:  Monthly geometric mean should not exceed 200 organisms/100 mL  Must have 5 samples per month  Standard Part 2:  No more than 10% of samples taken during a month can exceed 2000 organisms/100 mL  Standards only apply between April and October  Focused on geometric mean because less subject to random variation

Sunrise Water Quality Data  Data was collected from August-September in 1997, May- July in 1998, April-October in  Didn’t include 1997 data or previous data  Little data for seasons  Sampled at sites SUN-15 and SUN-5  Continuous flow data taken at SUN-5 and flow at other sites assumed to be proportional  Data for were grouped together if from the same month

Sunrise Water Quality Data

 Used month of June to calculate desired reduction because the month had the highest number of geometric mean exceedances  52% reduction=((geometric mean-standard)/geometric mean)  Seen as protective guideline  But three out of five sample sites had less than 5 samples, what was required by standard  Not mentioned how many ‘wet’ or how many ‘dry’ samples were taken  2002 had a wet summer; 2003 had a wet spring  Two seasons of data aren’t very representative of system; no dry or very wet years present

Source Assessment

TMDL and Allocations  Followed process developed by “Revised Regional TMDL Evaluation of Fecal Coliform Bacterial Impairments in Lower Mississippi River Basin in Minnesota”  WLA  North Branch Wastewater Treatment Plant  MS4  Determined from TMDL-WLA WWTP -MOS, which was divided between non- point and MS4 based on land percentages  Leaking septic systems; illegal straight pipes assumed to be zero  LA  Non-point: livestock, septic systems, wildlife, pets outside of MS4  Remaining 68% after WLA WWTP, MOS, and WLA MS4 were subtracted from TMDL

Margin of Safety and Reserve Capacity  MOS given by difference between the central and lowest value for each zone  Used this method because the allocations are direct functions of daily flows  MOS will account for flow variability  Reserve Capacity assumed equal to zero  As growth increases, assumed that fecal coliform will decrease  Sewer systems with disinfection will take the place of livestock populations

TMDL and Sources

Public Participation  Included organizations/persons such as:  Minnesota DNR, MPCA, Chisago SWCD, North Branch City Council, Wild River State Park, U of M Extension, volunteer stream monitors, landowners, and interested citizens.  Included a steering committee, public information meetings, and publications in local press

Monitoring Plan  Test specifically for E. coli instead of broadly fecal coliform  Monitor at same sites  Samples taken 5 times per month April through October  At least two seasons

Implementation  Focus on reducing top 3 sources (top 80%): unregulated livestock facilities, pasture near streams, and dangerous septic systems  Numerous financial incentives for landowners  Time frame: 5-10 years

Goals of Implementation  Reduce fecal coliform load from unregulated livestock facilities.  Store waste, vegetative buffer strips, move fences, clean lot  Reduce load from pastures near streams  Move livestock, rotational grazing  Reduce load from septic systems  Bring into compliance, switch to city sewer  Surface applied manure, pets, wildlife

Summary  Calculation of the components of the TMDL were valid (WLA, LA, MOS, Reserve Capacity)  52% reduction seems reasonable  Top three goals in implementation make sense  Valid to focus on those sources for implementation since they were derived from more reliable calculations  Would be easier to pinpoint and decrease (vs. wildlife fecal contamination)  The sources of those goals produced high amounts of fecal coliform during wet and dry periods

Summary  Could use more data  Not enough grab samples in between two seasons  Below requirement of 5 samples per month  Would make the geometric mean and therefore reduction goal more accurate if more samples were taken  Only two years used for data collection  Though they compared to 1998, could be helpful to include more years of data  Also, mentioned in beginning of report that there was close to 20 years of data; where is it/can it be used?  TMDL calculation was roughly approximated for some sources; however this couldn’t really have been improved