Water quality and quantity are being discussed more and more frequently as the world’s demand is increasing. According to the EPA (April 2008), 68% of community water systems supplied year-round use surface water. Surface water as well as groundwater, is greatly affected by not only environmental factors, but human influence. The most noticeable is our use of surface waters for recreation. Hamilton County contains both Morse Reservoir and Geist Reservoir, which were created for drinking water sources, but have also become popular for recreation.
EPA Factoids: drinking water and ground water statistics for 2007 March 2008, April 2008 at www.epa.gov
Between the months of April-October, the Hamilton County Health Department (HCHD) visits 19 recreational water sites including rivers, lakes, creeks and reservoirs. Each site is sampled once per month for E. coli. The water temperature and dissolved oxygen are also recorded at the time of sampling. E. coli are naturally occurring and are considered an indicator for the presence of harmful pathogens when found at increased levels. The EPA level considers 235 organisms/100mL of water or higher, unsafe for human body contact in recreational waterways. Dissolved oxygen (DO) is the measure of how much oxygen is dissolved in water. DO is essential to the organisms and creatures living in a body of water. DO can be affected by various factors including water movement (or stagnation), temperature and the presence of bacteria in water.
Hamilton County is in the Upper White River Watershed (UWRW) and receives both urban and agricultural run-off during high rain events. While most of the land in Hamilton County is used primarily for row crops and some livestock production, the urban and suburban expansion areas are rapidly increasing. According to the US Census Bureau 2010 Census, more than 30% of the citizens of the State of Indiana resides in the twelve of the sixteen counties that make up the vast majority of UWRW, and house the major cities within its borders, making it particularly susceptible to anthropogenic influences related to both agricultural practices as well as effects of urbanization (IUPUI). Surface waters are directly affected by these various sources of contamination carrying E. coli into the watershed. The more vegetated areas with grasses tend to soak up rainfall, directly increasing infiltration into the ground and reducing run-off into our recreational waterways. Land that has been developed with streets, roof tops, sidewalks, driveways and parking lots are impervious and create run-off into storm drains that eventually lead to our waterways. In the agricultural areas run-off can come from fields and animals. Heavy rain events wash manure from land into the waterways. An increase of E. coli is generally seen after these rain events as well as when water temperatures rise. E. coli is adapted to living in the intestines of warm-blooded animals, so it naturally thrives in warmer temperatures. Point source discharges such as septic system failures, storm water outfalls and wastewater treatment plant overflows also directly input E. coli into recreational waterways. (2015 HCHD water report)
Climate, population growth, public awareness, environmental concerns and various emerging public health issues are all factored into the HCHD Water Quality Program. Therefore, the water quality program is ever changing and growing. As Hamilton County continues to grow, there will be many challenges ahead for water quality. Climate change has already begun to show us how greatly water quality is affected by precipitation (both flooding and drought), water temperature fluctuations and air temperature changes. With continual growth, there will not only be an increase in water demand for drinking water, but an increase in recreational use as air temperatures increase during the summer months. As these demands increase, our water quality program will continue to expand and grow with the needs of public health.
E. coli is naturally occurring and present at varying amounts in natural bodies of water. As a result, the Hamilton County Health Department recommends that proper hand washing and bathing of both people and pets occurs after any interaction with an untreated body of water such as rivers, creeks, lakes and reservoirs. For more information, please check out our links to various other resources on water quality and monitoring.