Understanding Water Quality
What is water quality? From a regulatory standpoint, water quality is the measure of the condition of water relative to its designated use under state and federal law.
What is meant by ‘designated use’? For example, West Okoboji is designated as a ‘high quality recreational water,’ meaning the conditions of its waters must support “direct, prolonged and full body contact recreation such as swimming and water skiing”. West Okoboji is also a drinking water source, and has a special designation as an Outstanding Iowa Water, meaning it exceeds Iowa’s recommended water quality standards and should not be allowed to degrade to the allowable level. This is like expecting an A-student to maintain an A-level performance and not just a passing grade.
How is the protection of these designated uses enforced? Because the sources of impairment are so varied no single governmental unit or agency has overall jurisdiction. Some of these impacts – such as construction erosion or urban runoff - can be mitigated by good zoning, others – such as shoreline and wetland protection- are administered by state and federal laws. It takes educated citizens and organizations like the Okoboji Protective Association to see that zoning and protective laws are followed.
How is lake health determined? Water quality monitoring – taking water samples and analyzing them for pollution – is the best way to determine the health of lakes and must be ongoing as water quality conditions vary. Long-term data is necessary to determine the difference between natural variations and actual trends or changes in water quality. The OPA proudly supports the Cooperative Lakes Area Monitoring Project, the longest running lake monitoring program in Iowa. The Iowa DNR also runs a statewide lake monitoring system.
What is the biggest water quality threat to the Iowa Great Lakes? Excess nutrients and sediments are the major water quality concern for West Okoboji and all Iowa waters. Nutrients - such as phosphorus and nitrogen – are necessary for all life but in excess can cause noxious algae blooms, which can harm other aquatic life and drinking water supplies. No single source generates these pollutants. Their cumulative effect over time degrades water quality.
Where do these sources of pollution come from? Nutrient pollution comes from sewage, animal waste, fertilizer runoff from urban and agricultural areas, and other sources. Sediment pollution comes wind and water erosion when soils are left without vegetation during construction or after plowing. Additionally, wetland drainage and increasing urban development diminish the capacity of the earth to naturally store and filter water. The federal Clean Water Act divides these pollution sources into two categories: point source and non-point source.
What is meant by point-source and non-point source pollution? A point source is a single, identifiable source of pollution, such as a factory outlet pipe.Point-source pollution can be regulated and mitigated by treating water before discharge into receiving water.Non-point source pollution, by contrast, comes from several sources – such as urban and agricultural runoff- and is much more difficult to control and regulate. In fact, most efforts to control non-point source pollution are voluntary and unregulated.