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Introduction: What is Water Quality?

Environmental Water Quality versus Drinking Water Quality

The U.S. Geological Survey defines water quality as "a measure of the suitability of water for a particular use based on selected physical, chemical, and biological characteristics1." The "particular use" part of this definition is important because what makes water suitable for different uses can vary. For example, water from a pond with lots of algae may provide good habitat for fish 2 but not be healthy for people to drink.

Broadly speaking, there is a difference between environmental water quality and drinking water quality. Environmental water includes water out in the environment, including groundwater, surface water present in streams and lakes, and stormwater runoff. Stormwater runoff is rainfall that is not absorbed when it hits the ground. Instead, the runoff flows along the land or through drainage infrastructure until it reaches a stream or lake.

Public drinking water is sourced from the environment but is treated in a water treatment facility before being passed onto a municipal distribution network. Therefore, the contaminant profiles for environmental water and drinking water from the same area should not be the same. A finding of E. coli contamination in a local lake, for example, does not mean that E. coli will also be present in a community's drinking water. The purpose of a water treatment plant is to remove such environmental contaminants before they enter a city's drinking water supply.

In addition to this conceptual distinction between environmental water and drinking water, there is also a legal division in how the two categories of water quality are regulated. In the United States there are two primary federal statutes regulating water quality. Environmental water quality is overseen by the Clean Water Act (CWA) while drinking water quality is regulated by the Safe Drinking Water Act (SDWA). Both acts have the goal of promoting good water quality in the US. However, each act requires different types of testing and sets different permissible levels for the presence of certain contaminants. The CWA regulates the discharge of pollutants into water via a permitting program, called the National Pollutant Discharge Elimination System (NPDES), while the SDWA establishes national health-based standards for the quality of drinking water.

The Clean Water Act and Safe Drinking Water Act were developed in the wake of increasing public concern about water quality. In the United States, water quality issues caught the nation's attention in 1969 when oil and debris floating on the surface of the polluted Cuyahoga River caught fire outside of Cleveland, Ohio. Fires had occurred on the Cuyahoga River as early as 1936 3, but it was the 1969 fire that attracted the largest amount of media coverage. A few years later in 1972, Congress passed the Federal Water Pollution Controls Act, which later became known as the Clean Water Act. The Safe Drinking Water Act was passed shortly thereafter in 1974.

What human factors affect Bloomington's water quality?

The facilities of the City of Bloomington's Utilities Department (CBU) play a major role in local water quality issues. Bloomington sources its drinking water from Lake Monroe and cleans it for public distribution in the Monroe Water Treatment Plant. Wastewater (sometimes referred to as sewage) is treated in two facilities in Bloomington: the Dillman Road Wastewater Treatment Plant and the Blucher Poole Wastewater Treatment Plant. Treated water from these wastewater treatment facilities discharges into Clear Creek and Beanblossom Creek 4, respectively. Both the drinking water and wastewater treatment plants are operated by the City of Bloomington Utilities Department and conduct all reporting and testing mandated by the Clean Water Act and Safe Drinking Water Act.

In Bloomington stormwater runoff is not treated to remove contamination. The City's drainage system of human-constructed channels and underground pipes (culverts), called a storm sewer, simply directs stormwater downstream away from urban areas and back into lakes or streams. This separate stormwater infrastructure system is preferable to a combined sewage and stormwater sewer because a divided sewer reduces the possibility of raw sewage being released into the environment when heavy rains fill the stormwater culverts. Such an event is called a combined sewer overflow.

Storm drain marking Figure 1 - Three enthusiastic supporters of water quality from Bloomington North High School placing a "do not dump" sign on an inlet grate for Bloomington's storm drain system. Bloomington has a sanitary sewer (for transporting raw sewage to one of Bloomington's two wastewater treatment plants) separate from its storm sewer (for transporting stormwater downstream out of densely populated areas and back into local streams). You can help the environment by never dumping chemicals or trash down a storm sewer drain. (Photo by Kriste Lindberg)

In addition to the role of the Utilities Department, water quality in Bloomington is affected by various other local facilities that have permits to discharge effluent into the environment through the Clean Water Act's permitting program.

Ultimately, however, Bloomington's water quality is a reflection of cumulative actions of everyone who lives and works in the Bloomington area. This is because pollutants that are improperly disposed of can leach into or be washed by precipitation into our local waterways. There are many steps citizens can take to make a difference and improve local water quality. Positive actions include…

  • Minimizing fertilizer use
  • Refraining from dumping substances down storm drains
  • Installing silt fences when remodeling
  • Cleaning up after your dogs on walks
  • Regularly servicing your septic system
  • Not littering
  • Properly maintaining cars to prevent fluids from leaking onto the roads
  • Using a commercial car wash facility (they must treat wash water before discharging it) or washing your own car on a permeable surface like gravel with only biodegradable soaps

Septic tank maintenance is important because nitrogen and phosphorus can leach from a poorly maintained system into local waterways. For more ideas about how to do your part, visit

Human life depends on water. Lakes and streams provide us with sources of beauty, food, and recreation opportunities, as well as water for irrigation, manufacturing, and of course, drinking. However, many human activities have the potential to negatively affect the health of our waterbodies, jeopardizing both the welfare of the environment as a whole and the many benefits from lakes and streams on which we ourselves rely.

For this reason it is important to monitor water quality on an ongoing basis, identifying threats to the health of aquatic ecosystems, undertaking remediation as needed, and adopting preventative behaviors to protect the future wellbeing of our lakes and streams.

Defining Environmental Water Quality

The Clean Water Act: Designated Uses and Water Quality Standards

To protect water quality it is important to first clearly define water quality. In the Clean Water Act, water quality standards (WQS) for a given water body are expressed in goal form as "designated uses" (DUs) 5. Designated uses are established for each waterbody in the United States based on historical uses, current conditions, and other factors. The Clean Water Act does not allow any surface waterbody to be designated for use as a waste transport or treatment system 6.

shoreline Figure 2 - The shoreline of Monroe Reservoir, commonly called Lake Monroe. Lake Monroe is owned by the U.S. Army Corps of Engineers and maintained by the Department of Natural Resources (DNR). Like most waterbodies, Lake Monroe is used for multiple purposes. Among other functions, Lake Monroe serves as a flood control device, a source of drinking water, and a place of recreation.

Examples of designated uses for Indiana waterbodies include aquatic life support, drinking water support, fish consumption, and primary contact recreation (e.g. swimming). In cases where a water body has more than one designated use, which is typical, water management practices are based on the designated use requiring the most stringent water standards 7.

To be classified as able to support its designated use(s), a waterbody must meet the set of water quality criteria (WQC) associated with those uses 8. There are two types of water quality criteria: narrative and numeric. Narrative water quality criteria include descriptive statements such as that water must be "free from" various unwanted conditions. Numeric water quality criteria are quantified guideline levels for parameters such as dissolved oxygen and turbidity.

WQC make designated use categories more objective by specifying the criteria that, if met, allow for a designated use to take place on a given waterbody. Because water quality criteria differ for different designated uses, it is possible that a lake or stream will meet the standards associated with one of its designated uses while failing to meet the standards associated with other designated uses.

Monitoring and Major Assessment Reports

Once water quality standards are set, a waterbody must regularly be assessed to check whether it is meeting its standards. Given budgetary restrictions, regulators often choose to monitor some lakes and streams more closely than others depending on their commercial or environmental importance and regulatory history.

The Indiana Department of Environmental Management (IDEM) is responsible for monitoring and assessing the water quality of Indiana's surface waters. In accordance with section 305(b) of the Clean Water Act, IDEM's findings on environmental water quality in Indiana are published biannually in a document called an Integrated Water Monitoring and Assessment Report 9. IDEM submits their Integrated Report to the U.S. Environmental Protection Agency and also makes the report available to the public on their website.

Indiana's Integrated Water Monitoring and Assessment Report is a comprehensive assessment of the state's waterbodies and the degree to which they have met their respective water quality standards. The Integrated Report gets its name from the fact that it contains data from two important lists that, prior to 2002, were produced by IDEM as separate reports.

The two lists that make up the bulk of the Integrated Water Monitoring and Assessment Report are Indiana's Consolidated List and List of Impaired Waters. The Consolidated List, as required by section 305(b) of the Clean Water Act, contains monitoring and assessment data on all waters of the state of Indiana 10. Publication of the List of Impaired Waters is mandated by section 303(d) of the Clean Water Act 11.

The 303(d) List of Impaired Waters contains a subset of the waterbodies covered by the 305(b) Consolidated List 12. It includes data on only those waterbodies that are "impaired 13." and for which a TMDL (Total Maximum Daily Load, a pollution management plan that involves calculating the maximum amount of a pollutant a waterbody can receive and still meet water quality standards) is required.

Upon assessment, waterbodies are classified into one of 5 categories based on the degree to which they attain or violate water quality standards 14. A waterbody is considered to be impaired if it does not meet its water quality standards. If a waterbody is expected to violate the standards at some point within the next reporting cycle, it is considered threatened.

In Indiana, the water monitoring data used to develop the 305(b) assessments is collected on a five-year rotating basis 15. A group of lakes and streams representing roughly one-fifth of the state's surface waters is monitored each year so that over the course of five years, the entire state has been monitored. Because of this staggered review process, water quality reports do not always reflect the most current conditions. The 305(b) Integrated Water Monitoring and Assessment Report is published every other year in even year 16.

The most recent Integrated Water Monitoring and Assessment Report for Indiana can be found here on IDEM's website or here in pdf form.

Indiana also prepares a separate annual report detailing fish consumption advisories by waterbody and fish species. Fish consumption advisories are assigned to a particular fish species living within a particular water body. Due to differing contamination sensitivities, it is possible for different fish species within the same water body to be assigned to a different one of five possible consumption advisory groups. A group 1 consumption advisory implies that a fish species from a given waterway is safe for unrestricted consumption by the general population and for up to one meal per week for women who are breastfeeding, pregnant, or plan to have children. A group 5 consumption advisory signals that no fish of the species in question should be consumed from a given waterway 17.

The latest Indiana Fish Consumption Advisory Report can be downloaded here from the Indiana State Department of Health's website.

Total Maximum Daily Loads (TMDLs)

States are required to develop strategies for bringing water bodies listed on the 303(d) list into compliance with water quality standards. This usually involves the development of Total Maximum Daily Loads (TMDLs). The TMDL process establishes the maximum amount of a particular pollutant that a waterbody can withstand over a specified time period while still meeting water quality standards. After providing for a margin of safety and accounting for uncontrollable levels of pollution (e.g., background sources), each polluter or group of polluters is allocated a portion of the remaining TMDL.

Once the TMDL process has been successfully completed, the waterbody in question is listed under Category 4A on the 305(b) list. A schematic of how TMDLs fit into the methodology of how water bodies are classified in the Indiana Integrated Water Monitoring and Assessment Report can be seen in Figure 3. The list of Indiana waters with TMDLs and TMDLs under development for Indiana is subject to change as the Indiana Department of Environmental Management (IDEM) undertakes new remediation projects.

IDEM Consolidated Listing Logic Diagram 2010 Figure 3 - Flowchart of 305(b) classification methodology. AU stands for waterbody "assessment unit." A local example of an assessment unit would be Griffy Lake. Some particularly large or long water features in the Bloomington area, such as Lake Monroe and Clear Creek, are divided into multiple assessment units for monitoring purposes. Note how the flowchart shows that Category 3 waterbodies represent cases were there is insufficient data to determine an impairment level. (Graphic from IDEM18)

Water Pollution

Categorizing Water Pollution: Point Sources versus Nonpoint Sources

I. Point Sources

When a business or other source discharges contaminants into a stream or lake through a "discernible, confined, and discrete conveyance 19" such as an outlet pipe, it is classified as a point source. Common point source examples include factories, large construction sites, and wastewater treatment plants. Significantly, return flows from irrigated agriculture are not classified as point source pollution and are therefore not subject to the Clean Water Act regulations associated with point sources.

Point sources are generally required to obtain a National Pollution Discharge Elimination System (NPDES) permit. NPDES permits specify effluent limits, or how much of a given pollutant a particular point source can discharge. After the NPDES permit has been issued, the polluter is required to monitor its effluent and report the results to a regulatory agency. NPDES permit holders can be sued for permit violations by the government or by members of the public in what are known as "citizen suits." More details about the EPA's NPDES permit program can be found here. The role of the Indiana Department of Environmental Management in administering the NPDES permit process in Indiana is explained here.

II. Nonpoint Sources

Nonpoint sources can include any source of water pollution not considered to be a point source 20. Typical examples include runoff from agriculture, construction sites, streets, parking lots, and other impervious surfaces. Nonpoint source pollution can also come from sites used for the storage of industrial equipment or waste drums. Common pollutants introduced into the environment by nonpoint sources include phosphorus, nitrogen, pesticides, sediment, and pathogens like E coli. Although point sources are a significant concern, nonpoint sources are actually responsible for a greater portion of water body impairments than point sources 21. Contaminants from parking lots and high traffic streets tend to be the greatest contributors to stormwater pollution for most chemicals 22, but lawns have been found to contribute high phosphorus levels to runoff 23.

In 2009, a stream chemistry monitoring study funded by the Monroe County Drainage Board found that in the Bloomington-Ellettsville area, concentrations of nutrients, chloride compounds (from road salt), and pharmaceutical and personal care products increased in response to precipitation. This indicates non-point sources for these pollutants. The results of the study also suggest that protecting the water quality of Bloomington's streams is largely a matter of managing the quantity and quality of stormwater runoff.

Regulating nonpoint sources is difficult because they are numerous and varied, but a range of techniques broadly referred to as best management practices (BMPs) can be used to minimize the effects of nonpoint source pollution. Examples include the installation of vegetated roofs, rain gardens, bioswales, permeable pavers, and other Low-Impact Development practices. In Bloomington, for example, Miller-Showers Park functions not only as an attractive welcoming point for the City but as a stormwater retention facility, complete with holding ponds designed to retain stormwater that drains into the park from over 170 acres of downtown Bloomington. Another way to protect the environment from nonpoint source discharges is to cover storm drains if a spill of dangerous substances occurs. The purpose of this action is to prevent contaminants from spreading throughout the environment.

Everyone contributes to nonpoint water pollution in some way. From the drips of fuel from your car's tailpipe to your dog's waste left on the grass, everything adds up. Even reducing the area of pervious land (land able to absorb runoff) in town by building a home or sidewalk will affect stormwater runoff levels. To learn more about what you can do to reduce nonpoint source pollution, see EPA's page, "What you can do to prevent NPS pollution."

Common Water Pollutants

I. Phosphorus and Nitrogen

Runoff from fertilized fields, lawns, livestock operations, construction sites, pet wastes, and other nonpoint sources can carry phosphorus (P) and nitrogen (N) into streams and lakes. The growth of algae and rooted aquatic plants (macrophytes) in lakes is generally limited by a shortage of either nitrogen or, much more commonly, phosphorus. When runoff containing a waterbody's limiting nutrient is flushed into a lake or stream, algae and aquatic weeds grow rapidly. This excess plant growth changes the character of the waterbody and can interfere with recreational uses and strain the filtration systems of drinking water treatment systems. For suggestions on how you can help prevent excess nutrient loading of the lakes near where you live, visit the shoreline management resources available through the education section of the Indiana Lakes Management Society's website.

Rapid algal and macrophyte growth due to excess nutrient loading can also cause serious ecological problems. Heavy plant growth changes the type of habitat and nutrients available to aquatic wildlife. It can also lead to fish kills. The process used by bacteria to break down organic matter after plants die off uses up oxygen in the water. When large growths of algae or macrophytes die off, so much dissolved oxygen in the water can be used up that oxygen levels are depleted to levels below those needed to sustain other aquatic organisms, like fish. Lakes and streams are complex ecosystems. When nutrient loading from human sources is introduced to a body of water, the wildlife community in that body of water can become destabilized.

Water Quality Threat: Harmful Algal Blooms
Some blooms of blue-green algae (more accurately called cyanobacteria) can produce toxins that can lead to health problems and occasionally death for humans and domestic animals. Not all cyanobacteria produce toxins but the best practice if you see a water body that looks "soupy" from heavy algal growth is to not swim in it and be sure your children and pets also stay out of the water.

For more information on harmful algal blooms, read the U.S. Geological Survey's fact sheet on harmful algae blooms (HABs) or the latest updates on blue-green algae in Indiana.

II. Sediment

It may seem strange that sediment is considered to be a pollutant but when human activities cause lakes and rivers to receive more sediment than they would naturally, it can lead to significant problems for aquatic ecosystems. Excess sediment generally comes from runoff that has flowed over areas with exposed soil or other debris, such as construction sites, logging areas, farms, and roads. Streambed erosion also contributes to sediment pollution.

Sediment can reduce the amount of light available to aquatic plants, increase water temperature, bury and suffocate fish eggs, and irritate fish gills 24. Additionally, sediment can carry other pollutants such as phosphorus, nitrogen, heavy metals, oil and grease, PCBs, and pesticides, which themselves cause considerable damage. Contaminated sediment is especially problematic for organisms living at the bottom of a waterbody because it tends to settle on the bed of streams or lakes.

Sediment pollution concerns are addressed in the Siltation and Erosion Prevention section of Bloomington's Municipal Code, which is 20.05.040 - EN-03. Environmental standards for erosion control are also discussed in sections 20.05.041 - EN-04, 20.05.045 - EN-08, and 20.07.150 - SM-01 of the Code. Erosion control measures required for construction projects are discussed in sections 10.21.070 and 10.21.080 of the Bloomington Municipal Code. Erosion mitigation required for developments on steep slopes is described in 20.05.039 - EN-02 and general drainage standards are outlined in section 20.05.034 - DS-01.

III. Toxic Contaminants

Physical and chemical characteristics of water such as temperature and pH can be altered to a problematic degree as a result of human activity within a watershed. Various chemicals such as heavy metals (e.g., lead and mercury), pesticides, polycyclic aromatic hydrocarbons (PAHs) are common sources of concern as potential threats to water quality.

Often pollutants can become present at higher and higher concentrations as they travel up the levels of a local food chain. This process is called biomagnification. As an organism (such as a fish) consumes many smaller organisms (such as insects) each containing a comparatively low amount of a given pollutant, that pollutant can build up in the tissues of the organism doing the eating. Thus, the concentrations of a pollutant in the body of organisms living in a waterbody will tend to be higher than the concentration of that pollutant in the surrounding water. Biomagnification applies particularly to contaminants that take a long time to break down, such as PCBs, and is generally the biological reason why certain fish are designated in fish consumption advisories as unsafe to for people to eat.

Water Quality Indices

Because there are so many possible sources of water quality degradation, scientists and environmental agencies use a variety of parameters to describe water quality. Some of the more common measurements for streams include the Index of Biotic Integrity (IBI), which analyses streams in terms of the biological community they support, and the Qualitative Habitat Evaluation Index (QHEI), which looks at a stream's physical characteristics.

For lakes, the Carlson Trophic State index (TSI) is often used. The Carlson TSI uses a mix of physical and biological measurements, including Secchi disc transparency (a measure of water clarity), chlorophyll a levels (a measurement of algal growth), and total phosphorus (a measure of nutrient loading). For both lakes and streams, measurements of dissolved oxygen, nutrient (most commonly nitrogen and phosphorus) levels, pH, light transmission, and dissolved solids are relevant. For information about how to monitor a lake, visit the website of the Indiana Clean Lakes Program. For a local example of how TSI data is used, read the latest annual lake monitoring report from the Lake Lemon Conservancy District.

I. Index of Biotic Integrity

The IBI is a composite index that compares a stream's water quality to a reference stream that is considered to be of high quality. Researchers gather fish samples that are used to determine a variety of factors such as the number and diversity of species present, whether the stream supports sensitive species, and whether various levels of the food chain are adequately represented. Many versions of the IBI have been developed but in each incarnation, individual metrics are assessed and the values assigned for each metric are then summed to produce an overall IBI score for the stream 25. The higher the overall score, the higher the quality of the stream's biological community.

II. Qualitative Habitat Evaluation Index

The QHEI complements the IBI, providing a physical characterization of the stream habitat in question. Factors such as the type and quality of substrate, the width and quality of the floodplain, the degree to which the stream banks suffer from erosion, sinuosity (whether the stream is straight or bends), and whether the stream has been channelized, are analyzed to determine the overall quality of the stream habitat 26. The maximum possible score, indicating the highest possible habitat quality, is 100.

III. Carlson Trophic State Index

With the Carlson Trophic State Index (TSI), scientists use water clarity (measured as Secchi disc transparency) and the levels of total phosphorus and chlorophyll pigments in a lake to estimate a lake's algal biomass, or productivity 27. Lakes with TSI values greater than 50 are said to be eutrophic, or very productive lakes (i.e. those that support large populations of plants and algae). Lakes scoring between 40 and 50 are mesotrophic, or moderately productive. Those scoring less than 40 are called oligotrophic. Oligotrophic lakes are associated with low biological productivity and are typically characterized by high water clarity. Nutrient loading influenced by human activity, such as when storm runoff from fertilized lawns or cropland runs into a lake, has the potential to lead to rapid lake eutrophication.

Eutrophication is not a byword for water quality degradation.
The point at which a lake is considered overly eutrophic (producing too much plant and algal biomass) depends on how that lake is used. Example: Oligotrophic lakes are attractive to water skiers and other recreational water users because of their high water clarity but cannot sustain high populations of sport fish. Research has found that in temperate lakes where phosphorus is the nutrient limiting algal growth (as is true for most Indiana lakes), lakes become eutrophic once the total phosphorus concentration exceeds about 40 µg/L. Sport fish populations, however, do not peak at less than approximately 100 µg/L of total phosphorus 28.

Large algal blooms can be a nuisance to humans, but algae are the base of the food chain in lakes. In crystal-clear, algae-free waters fish populations are limited, if present at all. Therefore, lake users advocating for maximum water clarity may be in conflict with those who want to use a lake primarily for fishing.

Bloomington/Monroe County Surface Waters


The City of Bloomington lies on the divide between the Lower East and West Fork basins of the White River watershed (Figure 2). Clear Creek is the primary drainage for the southern two-thirds of Bloomington while Griffy Creek and other tributaries of Beanblossom Creek provide drainage for the northern part of the City 29.

Clear Creek flows southwest across the IU campus, where it is known as the Jordan River, then flows south through Bloomington and beyond. Along much of its course in Bloomington, Clear Creek is enclosed in culverts (underground pipes) or constructed channels. South of Bloomington, Jackson Creek and other smaller tributaries feed into Clear Creek. After merging with Jackson Creek, Clear Creek receives effluent from the Dillman Road Wastewater Treatment Plant. South of the Monroe Lake Dam, Clear Creek joins Salt Creek, which then drains into the East Fork of the White River.

monroe co suface water map 2012 version Figure 4. Monroe County Surface Waters

Stout Creek and Griffy Creek flow north from Bloomington and drain into Beanblossom Creek along with other small tributaries. Beanblossom Creek flows to the northwest, eventually draining into the West Fork of the White River. The East and West Forks of the White River merge about 75 miles southwest of Bloomington at the northern border of Pike County, just east of Vincennes. The White River eventually discharges to the Wabash River in southwestern Indiana.


There are three significant lakes in Monroe County: Lake Monroe, Lake Lemon, and Griffy Lake. Each of these is a human-constructed impoundment (reservoir) rather than a naturally formed lake.

The largest of the three is Lake Monroe, which provides drinking water to Bloomington. Though almost entirely within Monroe County, the reservoir also extends into Brown County. Lake Monroe's watershed (the area of land from which water drains into the reservoir) includes not only Monroe County but Brown, Bartholomew, Jackson, and Lawrence Counties as well. 88% of Lake Monroe's surface area but only 21% of the reservoir's watershed is located in Monroe County 30. Approximately 56.1% of Lake Monroe's watershed is situated in Brown County 31.

Lake Lemon is the second largest lake in the Monroe County area. The lake is managed by the Lake Lemon Conservancy District, which is responsible for maintaining the lake's water quality and value as both a wildlife habitat and recreational site.

Located on the north side of Bloomington, Griffy Lake is the only sizable lake within Bloomington itself. Griffy Lake once served as Bloomington's water supply and is now considered to be an emergency backup source for drinking water. Though it is owned by the City of Bloomington Utilities, the Bloomington Parks & Recreation Department manages the lake and surrounding land. Information on management strategies for Griffy Lake as well as additional history about the reservoir can be found in the latest Griffy Lake master plan.

Defining Drinking Water Quality

The Safe Drinking Water Act

The Safe Drinking Water Act (SDWA) establishes national standards for the quality of drinking water supplied by public water systems. Unlike the Clean Water Act, which focuses on minimizing water pollution in surfaces water bodies (rivers and lakes), the Safe Drinking Water Act regulates all drinking water whether it is sourced from surface water or groundwater supplies 32. The SDWA sets standards for acceptable levels of various water contaminants based on the risk posed by a given substance to public health. The SDWA does not regulate private wells which serve fewer than 25 individuals 33.

Once the EPA has identified a contaminant it wants to regulate under the Safe Drinking Water Act, it determines two guidelines for the contaminant: a maximum contaminant level goal (MCLG) and a maximum contaminant level (MCL) [34|#34. The MCLG is the level of a contaminant in drinking water below which there is no known or expected health risk. The MCL is the maximum permissible level of a contaminant in public drinking water. An MCL is an enforceable standard set as close to the MCLG as is economically or technologically feasible. MCLs can change as new treatment technologies are developed.

In some cases when it is not feasible to set a maximum contaminant level or when it is difficult to detect contaminants in drinking water, the EPA will instead establish a required treatment technique (TT) 35. A treatment technique is a procedure that specifies how public water systems must treat their water to remove certain contaminants.

National Primary and Secondary Drinking Water Regulations

Together, the list of maximum contaminant levels (or treatment techniques) required for all drinking water contaminants regulated by the EPA make up a set of legally enforceable standards that apply to public water systems and are called the National Primary Drinking Water Regulations (NPDWRs, or primary standards). The full list of primary standards that public water systems, such as the City of Bloomington Utilities, are federally mandated to test for can be found here. Primary standards protect drinking water quality by setting limits for contaminants that can adversely affect public health and are known or anticipated to be present in water.

In addition to primary standards, the EPA also has a list of secondary standards, which are standards for contaminants that may adversely affect aesthetic qualities of water such as odor and taste. Because secondary contaminants have no known adverse public health impact, it is suggested but not required for public water systems to monitor for them 36. Secondary contaminants include aluminum, chloride, color, copper, corrosivity, fluoride, foaming agents, iron, manganese, odor, pH, silver, sulfate, total dissolved solids, and zinc. Bloomington's drinking water is tested for all primary and secondary standards 37.


1. U.S. Geological Survey. "A Primer on Water Quality." Online available at Last accessed 26 Oct 2011.

2. Ney, John. J. "Oligotrophication and Its Discontents: Effects of Reduced Nutrient Loading on Reservoir Fisheries." American Fisheries Society Symposium. 16. 285-295.

3. U.S. Environmental Protection Agency. "Cuyahoga River Area of Concern: Beneficial Use Impairments." Online available at Last accessed 26 Oct 2011.

4. City of Bloomington Utilities. "Water Quality Information." Online available at Last accessed 26 Oct 2011.

5. U.S. Environmental Protection Agency "Designated Uses." Online available at Last accessed 26 Oct 2011.

6. U.S. Environmental Protection Agency. "WQS: Designating Waterbodies." Online available at Last accessed 26 Oct 2011.

7. Ibid.

8. U.S. Environmental Protection Agency. "Water Quality Criteria." Online available at Last accessed 26 Oct 2011.

9. Indiana Department of Environmental Management. "Integrated Water Monitoring and Assessment Report: 2008." Online available at Last accessed 19 Jan 2011. 3.

10. Ibid.

11. Indiana Department of Environmental Management. "Integrated Water Monitoring and Assessment Report: 2008." Online available at Last accessed 19 Jan 2011. 3.

12. Ibid.

13. Indiana Department of Environmental Management. "Integrated Water Monitoring and Assessment Report: 2008." Online available at Last accessed 19 Jan 2011. 3.

14. Indiana Department of Environmental Management. "Integrated Water Monitoring and Assessment Report: 2008." Online available at Last accessed 10 Jan 2012. 42.

15. Indiana Department of Environmental Management. "Integrated Water Monitoring and Assessment Report: 2008." Online available at Last accessed 28 Oct 2011.

16. Indiana Department of Environmental Management. "Impaired Waters - Integrated Report." Online available at Last accessed 12 Jan 2012.

17. Indiana State Department of Health. "2010 Indiana Fish Consumption Advisory Complete Report." Online available at Last accessed 28 Oct 2011.

18. Indiana Department of Environmental Management. "Integrated Water Monitoring and Assessment Report: 2010. Appendix C."

19. U.S. Environmental Protection Agency. "Clean Water Act, Section 502 General Definitions." Online available at Last accessed 28 Oct 2011.

20. U.S. Environmental Protection Agency. "What is Nonpoint Source Pollution?" Online available at Last accessed 28 October 2011.

21. U.S. Environmental Protection Agency. "Introduction to the Clean Water Act. Section 319: Nonpoint Source Program." Online available at Last accessed 28 October 2011.

22. Bannerman, R., D. Owens, and N. Hornewer. "Sources of Pollutants in Wisconsin Stormwater." Water Science Technology. 28(3-5). 1993. 241-259.

23. Steuer, J.. "Stormwater pollution sources areas isolated in Marquette, Michigan." Technical Note #105 from Watershed Protection Techniques. 3(1). 609-612. 1997.

24. Water on the Web. "Soil Erosion and Sediment Pollution." Online available at 2004. Last Accessed 28 October 2011.

25. U.S. Environmental Protection Agency. "An Introduction to the Index of Biotic Integrity." Online available at Last accessed1 November 2011.

26. Ohio State University. "Qualitative Habitat Evaluation Index." Online available at Last accessed 1 November 2011.

27. Carlson, R.E. and J. Simpson. "A Coordinator's Guide to Volunteer Lake Monitoring Methods." North American Lake Management Society (Summary). 1996. Online available at Last accessed 1 November 2011.

28. Ney, John. J. "Oligotrophication and Its Discontents: Effects of Reduced Nutrient Loading on Reservoir Fisheries." American Fisheries Society Symposium. 16. 285-295.

29. Monroe County Planning Department. April, 2004. "Unincorporated Monroe County Storm Water Quality Management Plan, Part B." 5.

30. Eakin, Jason. Monroe County Planning Department. Natural Features Inventory: Watershed & Floodplains. Online available at Last accessed 2 November 2011. August 2003.

31. Ibid.

32. Ferrey, Steven. Environmental Law: Examples and Explanations. Fifth Edition. "Additional Federal Water Pollution Statutes." New York: Aspen, 2010. 283-290.

33. U.S. Environmental Protection Agency. "Safe Drinking Water Act." Online available at Last accessed 28 October 2011.

34. U.S. Environmental Protection Agency. "Understanding the Safe Drinking Water Act." Online available at Last accessed 28 Oct 2011.

35. U.S. Environmental Protection Agency. "Understanding the Safe Drinking Water Act." Online available at Last accessed 28 Oct 2011.

36. U.S. Environmental Protection Agency. "Drinking Water Contaminants." Online available at Last accessed 1 Nov 2011.

37. Miya, Shawn (City of Bloomington Utilities, Pretreatment Program Inspector). 15 November 2011. Personal communication.