History of Iowa Beach Monitoring
History of Monitoring
The Iowa Department of Natural Resources’ (Iowa DNR) state park staff began monitoring 12 state-owned beaches in 1999. Iowa’s Ambient Water Monitoring Program expanded the monitoring to include 31 beaches in 2000, which were sampled by Iowa DNR park staff. By 2001, 35 state-owned beaches were incorporated into the beach-monitoring program. Beginning in 2002 and continuing through 2004, the University of Iowa Hygienic Laboratory (UHL) began taking the state-owned beach samples. Two additional beaches were added in 2003, bringing the total number of monitored beaches to 37. From 2000 through 2003, these beaches were monitored for three types of fecal indicator bacteria: fecal coliform, E. coli, and enterococci. Analysis of the bacteria data from these four years indicated that fecal coliform and E. coli in Iowa waters are closely related, with E. coli being approximately 94% of fecal coliform. For this reason, fecal coliform was dropped from the monitoring program in 2004 and the state-owned beach samples were monitored for E. coli and enterococci only. Additionally, enterococci was dropped from most beaches in 2005 as the US EPA has suggested that this indicator will not be used in freshwaters in the future.
After several years of monitoring state-owned beaches, the DNR received several requests to monitor other beaches across the state. The county beach monitoring program was initiated in 2004 with 34 county managed beaches participating. Iowa DNR staff visited each beach to train county park staff to take beach samples in the same manner that samples were taken at the state-owned beaches. These county-beach samples were analyzed for E. coli bacteria. In 2005, 28 county beaches are participating in this program.
History of Sample Collection
During the years 1999 through 2001, Iowa DNR park staff collected bacteria samples weekly from Memorial Day through Labor Day at the state-owned beaches. Park staff took a single water sample in approximately waist deep water at the center of the beach. After collection, the samples were placed in a cooler and shipped overnight to UHL for analysis.
Beginning in 2002, samples were collected from April 15 through October 31 to more closely follow the recreational season in Iowa. In addition, the sample collection process at the state-owned beaches was revised to develop an understanding of bacteria levels along the entire beach. A composite sample was taken from nine points at the beach: three depths (ankle-, knee- and chest-deep) and three transects along the beach (the two edges of the beach and the center). Water from these nine points was combined into a bottle and one sample was taken from the mixed water. Since 2002, UHL staff began collecting the weekly beach samples and transporting them to their facility for analysis.
Another addition to the state-owned beach sampling routine in 2002 was the collection of field data. Dissolved oxygen, turbidity, pH, and temperature were measured at knee depth in the center transect during the weekly sampling at each beach. Other descriptive information was also collected, including estimated wind speed and direction, estimated wave height, number of swimmers, number of wildlife, and number of boats. This additional information has been collected to help better understand the effect of environmental conditions and outside influences on water quality. The field parameters and descriptive information continue to be collected at the state-owned beaches to assist in the characterization of the beaches.
Beach Monitoring Season
The state-owned beach monitoring season was changed in 2004 to reflect the frequency of elevated bacteria levels at particular beaches. Using data from 2000 through 2003, those 14 state-owned beaches with two or fewer samples exceeding the one-time maximum standard were monitored less frequently. Monitoring began the week before Memorial Day and continued though Labor Day. This process is set to continue, with any beach that has had little trouble over a running 5 year period being monitored less frequently. All other state-owned beaches are scheduled to be monitored April 15 though October 31. However budget constraints, have caused the monitoring to began in May during both the 2004 and 2005 seasons.
Beginning in 2004, county park staff were trained by Iowa DNR personnel to take beach-monitoring samples in the same manner described above. Samples at the county beaches were taken from Memorial Day through Labor Day. County staff personnel did not collect any field data at their beaches.