Record Display for the EPA National Library Catalog


Main Title Estimated Loadings from Seven Michigan Tributaries and Recommendations for Tributary Sampling Strategies
Author Day, Robert M. ;
CORP Author Surface Water Quality Division, Michigan Department of Natural Resources, Lansing, MI.
Publisher Jan 90
Year Published 1990
Report Number EPA/905/4-90/001; MI/DNR/SWQ-90/010
Stock Number PB91-125823
Additional Subjects Phosphorus ; Water quality ; Michigan ; Study estimates ; Monte Carlo method ; Concentration(Composition) ; Loading rate ; Trends ; Water flow ; Numerical analysis ; Site surveys ; Graphs(Charts) ; Water pollution sampling ; Tributaries ; Water runoff
Internet Access
Description Access URL
Library Call Number Additional Info Location Last
NTIS  PB91-125823 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 99 p.
Annual load estimates of twelve parameters from seven Michigan tributaries were calculated from 1984 to 1986. Estimates were calculated by dividing sample concentrations into high and low strata and applying Beale's Ratio Estimator. The greatest annual loads of the twelve parameters usually came from the St. Joseph followed by the Black or Rouge rivers and the lowest annual loads came from either the Pere Marquette or Ontonagon rivers. Monte Carlo studies indicate that flow stratified sampling strategies yield unbiased and relatively precise total phosphorus load estimates when the samples were selected randomly. Strategies that confine sampling to the first half of the year or neglect either the rising area or falling area of the hydrograph will yield biased load estimates. A systematic sampling strategy will insure that each sample within each strata has an equal probability of being selected and usually yields unbiased total phosphorus load estimates. Sample sizes necessary to estimate total phosphorus loads were calculated for four of the seven Michigan tributaries studied using load average and variance predicted by flow variability versus load variability regression equations. This method can be used to provide sample size estimated for many tributaries with little or no prior information about total phosphorus concentrations but is not reliable for the most event responsive rivers.
"Project Nos. S-005741-01-2, S-005741-02-1, S-005741-03"