Water+quality

=// **Water Quality** //= //by L. Mitchell and M. Preut//

= INTRODUCTION = When it comes to water quality management in streams, the objective is to control pollutants (i.e. chemicals, organic and inorganic compounds) so that water quality is not degraded below the natural background level (Davis, Cornwell, 2008). This background water quality is usually based on historical data if available or from data from a similar, uncontaminated “proximal” water body. This determination of background water quality would be the quality without human intervention. Once the natural background is established then acceptable levels can be decided for the intended use(s) of the water. For instance, arsenic can be part of the natural background level in geographic areas with a history of volcanic activity, and so water quality is not degraded because of its presence. However, once the background quality is established, it may be decided the decrease in the amount of arsenic is needed to make the water available for drinking. It is important to be able to measure natural background and contaminating pollutants and predict the impact of the pollutant on water quality. Our objective will be to provide a summary of some water quality principles, the impact of water quality considerations on stream restoration, and the effectiveness of several ecological techniques for managing water quality.

= WATER QUALITY PRINCIPLES = The Clean Water Act (CWA) was established in 1972. The objective of the CWA is to “restore and maintain the chemical, physical, and biological integrity of the nation's waters" - Clean Water Act (CWA) section 101 (a). The Environmental Protection Agency (EPA) enforces this act. Hence, the EPA is responsible for regulating the pollution and water quality of the United States’ surface water and controls any point source pollution, (any pollution from a single, identifiable source), that may occur with National Pollutant Discharge Elimination System (NPDES) permits. Any man-made conveyance into a river, stream, or creek, otherwise known as navigable waters is required to meet certain standards that are outlined in the NPDES permits. These permits require that any point source monitor and report levels of contaminants being discharged. The EPA defines allowable amounts of various nutrients, chemicals, sediment, and other limits that are permissible in a water body. Any violation of these regulated measurements is subject to severe fines.

Total maximum daily loads (TMDL) specify the maximum amount of pollutant that a water body can receive and still meet water quality standards. It allocates pollutant loadings (the mass of pollutant) that may be contributed among point and nonpoint sources. It is computed on a pollutant-by-pollutant basis from a list of pollutants for individual water bodies. Meeting TMDLs is often a driver for restoration projects.

To affect water quality and meet TMDLs, three parameters are involved. Those parameters are chemical, physical and biological in nature and work together to contribute to or degrade water quality.

** Chemical Processes **
For the purpose of simplification, when we talk about chemical processes in water quality we are concerned with the amounts of dissolved oxygen (DO), pH and ammonia (or nitrates) present in a water body. These three components have a large impact on the health of a water body and are more easily addressed by the ecological restoration techniques addressed later.

Oxygen diffuses (dissolves) into water as it goes from an area of high concentration to an area of low concentration. But the solubility of oxygen in water is so small that diffusion alone, in still water, can take a long time. We’re talking in the order of years just to diffuse from the surface to a depth of about 19 feet. So, almost all oxygen diffusion occurs in the presence of surface water agitation. The other source for dissolved oxygen comes through the photosynthesis process of plants. This oxygen supply can occur only to the depth for which light can penetrate. Which means it is also limited to daytime production and seasonal production.
 * Dissolved Oxygen **

Altitude of the body of water and prevailing weather conditions can be factors that also affect the amount of dissolved oxygen in water. There is less oxygen content at higher altitudes and in warmer waters. Incidentally, DO also decreases in more saline waters.

Aquatic plants have a substantial effect on DO levels. During the day their photosynthetic activities produce oxygen that supplements the reaeration of water and can even cause oxygen supersaturation. Supersaturation may cause embolisms or gas bubbles in the blood stream of some fish. More often, if water is supersaturated, the excess oxygen will tend to release from the water and diffuse to the air. Plants also consume oxygen for respiration processes. Plant respiration can severely lower DO levels during the night. Plant growth is usually highest in the summer when flows are low and temperature is high so that large nighttime respiration requirements coincide with the worst cases of oxygen depletion from BOD exertion. Oxygen is also lost by the decomposition of organic matter. When aquatic plants die and settle to the bottom, they increase the benthic demand (oxygen uptake in the lowest bed zone). As a general rule, large growths of aquatic plants, especially algae, are detrimental to maintenance of consistently high DO level.

The concentration of DO is an indicator of general health of a stream and all streams have some capacity for self-purification which correlates to the amount of DO present in water stream. Assessing DO is the beginning point for water quality management. With DO we are concerned with the demand placed on oxygen as well as its production. Keep in mind that in the air, oxygen makes up about 21% of the volume; however, in water, oxygen makes up only about 0.0001%. So you can never have too much DO in a water body. As a minimum, a stream should have 2 mg/L (2 ppm) of DO, most game fish however, need about 4 mg/L (4 ppm) of DO to live, many fish will not swim in waters below 2 to 5 mg/L (2 to 5 ppm) DO (exceptions would be carp and tropical fish--think warm water fish where oxygen tends to be lower--which can live in the 1 to 2 mg/L (1 to 2 ppm) DO).

pH, the measure of how acidic or basic a water is, ranges from 0 to 14 with 7 being neutral. Just like people, fish like a pH of about 7 (neutral). A pH lower than 7 is acidic or has more free hydrogen ions [H+] in solution while a pH over 7 is basic and indicates there are more hydroxyl ions [OH-] in solution. This determines how effectively the water can dissolve chemical components in water such as nutrients like phosphorous and nitrogen, for the use by aquatic life. Because pH is a chemical indicator, changes in pH indicate that chemical changes are happening in a water body (i.e., acidic water causes metals to release into water).
 * pH **

Algal growth removes carbon dioxide from the water during photosynthesis which in turn can cause an increase in pH levels. A healthy water system will have a natural ability to “buffer” changes in pH. Photosynthesis will use up dissolved carbon dioxide and reduce the acidity of water, so pH increases. At the same time respiration and decomposition of this organic matter will produce CO2 which lowers pH. A balanced process will help control overall range of pH. It is important to note, the significance in the change of pH values has more to do with indication that chemical components are becoming more or less soluble in pH conditions and influences the availability of nutrients to aquatic life or the solubility of chemical compounds toxic to aquatic life.

Nitrogen in the form of ammonia (NH3) is a needed nutrient by aquatic plants. Nitrogen released into surrounding water is ammonia NH3, but in high concentration, this nutrient becomes toxic to fish. An overabundance of the nutrient also contributes to algal growth which when they die and settle to the bottom places additional oxygen demand on the system. Ammonia as NH4 (ammonium) converts to nitric acid and will consume large amounts of DO. So ammonia and nitrates, though they are nutrients, are pollutants when they are overabundant in a system.
 * Ammonia and Nitrates **

= Physical Processes = Characteristics of the individual river help determine the impacts of pollution, such as:
 * Volume – large river volume can dilute pollutants.
 * Stream flow; high and low - affects water retention, recharge and DO levels.
 * Temperature - effects water's ability to hold oxygen and effects which aquatic life will be present.
 * River depth – affects water retention and water temperature.
 * Type of river bottom – affects infiltration, affects flow.
 * Surrounding vegetation – affects water retention by decreasing evaporation, deters bank degradation.
 * Sediment loads – affects substrate conditions, affects survival of microorganisms and fish, affects temperature, and affects channel stability.
 * Climate of the region - affects temperature, rate of water evaporation
 * Mineral heritage of the watershed - contributes to pH
 * Types of aquatic life - sources of biological oxygen demand
 * Land use patterns (i.e. urban vs. agricultural use) - point and nonpoint sources of pollutants and oxygen demand.

Some rivers are very sensitive to pollutants like sediment, salt and heat while other rivers can tolerate large inputs of these pollutants without much damage. Water quality will mean different things to different systems. Some examples will be discussed later.

Biological Processes
A healthy body of water needs properly functioning physical, chemical and biological processes. A river with low chemical or physical quality will have low biological integrity, and vice versa. Karr and Dudley (1981) define biological integrity as “the ability to support and maintain a balanced, integrated adaptive assemblage of organisms having species composition, diversity, and functional organization comparable to that of natural habitat of the region." (Karr and Dudley 1981, Karr et al. 1986). It has been a common ideology that water quality is chemical in nature. The EPA uses permits to monitor any point source pollution and these permits dictate allowable levels of Ammonia, pH, Nitrogen etc.; all chemical components, however biological integrity has recently gained more attention in water quality issues and restoration approaches because it is thought to be a suitable indicator of a water body's health. Foodwebs are evidence of this ideology and how biology is viewed in river restoration.

The Index of Biotic Integrity (IBI), originally developed in 1981 by Dr. James Karr is a statistical measurement of the effects of anthropogenic actions on biological systems. The IBI has since been modified several times and adapted based on the location of the study, but the original index comprised of twelve metrics that indicated the biotic integrity of a system. These metrics are biological attributes, or measurable properties belonging to living organisms that have the ability to be altered by human interaction and are divided into five subcategories:

**Species Richness and Composition Metrics** **Indicator Species Metrics** **Trophic Function Metrics** **Reproductive Function Metrics** **Abundance and Condition Metrics**
 * Total Number of Fish Species (total taxa)
 * Number of Catostomidae Species (suckers)
 * Number of Darter Species
 * Number of Sunfish Species
 * Number of Intolerant or Sensitive Species
 * Percent of Individuals that Are //Lepomis cyanellus// (Centrarchidae)
 * Percent of Individuals that Are Omnivores
 * Percent of Individuals that Are Insectivorous Cyprinidae
 * Percent of Individuals that Are Top Carnivores or Piscivores
 * Percent of Individuals that Are Hybrids
 * Abundance or Catch per Effort of Fish
 * Percent of Individuals that are Diseased, Deformed, or Have Eroded Fins, Lesions, or Tumors (DELTs)

Table 1: “An Introduction to the Index of Biotic Integrity”, [] These metrics are assigned numerical values based on the expectation of what the system might look like had there been no human disturbance. They are then categorized and defined on a gradient of anthropogenic influence (see example to the right). Alterations of management practices are then devised to improve the biological integrity.

"A bioindicator is an anthropogenically-induced response in biomolecular, biochemical, or physiological parameters that has been causally linked to biological effects at one or more of the organism, population, community, or ecosystem levels of biological organization." __http://www.esd.ornl.gov/programs/bioindicators__

This is a qualitative way of monitoring water quality and can tell researchers about the extent of pollution in the environment due to the responses of the organisms present. These responses can be short-term with low ecological relevance, such as elevated water temperatures in the summer causing algal blooms and dissipating when the weather cools, to long-term with high ecological relevance such as hormones causing fish to change sexes and without males, reproduction decreases and the fish population dies.

Biomonitors are a quantitative way of measuring water quality. They are the actual organisms and are categorized in several ways that can indicate a variety of chemical or physical influence in a river system. It is thought by those who support the IBI that biomonitors can tell us much more about water quality than the chemical or physical processes might. For example, a fish kill can be evidence of not only the degree of pollution, but also the length and severity of exposure. There are five categories of biomonitors and each can be studied in different contexts.

Macroinvertebrates ororganisms that have no backbone are widely used biomonitors. Most macroinvertebrates are insects; however, these can also be crustaceans and mollusks. They are extremely sensitive to their surroundings and can indicate physical changes in the ecosystem as well as chemical pollutants. In a study performed by Alvaro Alonso and Julio Camargo, they observed the effects of ammonia on the behavior of an aquatic snail (Potamopyrgus antipodarum). Contaminant free snails were collected from the Henares River in central Spain and slowly began to introduce ammonia into their systems. These snails were chosen for their high tolerance to lethal long-term exposure to NH 3 in order for their behavior to be examined without mortality interfering. Alonso and Camargo monitored the time it took for the snails to move when provoked and compared this with a control snail that moved “normally”. They found that after forty days of exposure to different concentrations of ammonia, the snails did not die. However, despite being tolerant to the NH 3, they were very sensitive to it. Alonso and Camargo found that at very low concentrations (0.02 mg/L), the snails reacted slower than the control snail, with the snail receiving the highest concentration of 0.13mg/L taking almost 30 seconds longer to start normal movement after 40 days of exposure ( Alonso & Camargo, 2009 ). This study concluded that as a bioindicator, macroinvertebrates are sensitive to pollutants and just because their mortality rate is not affected does not mean that the ecosystem is unchanged.

Animals, usually fish in the case of water quality, are also biological indicators of water quality. An abundance of a certain species or lack thereof is a strong sign of a change in water quality. Using the Rio Grande’s own silvery minnow in 2002, the U.S. Department of The Interior, U.S. Fish and Wildlife Service and The New Mexico Ecological Services Field Office evaluated the Rio Grande’s water quality, “Twenty-nine fish samples were collected from 14 sites within the Middle Rio Grande and analyzed for trace elements, total mercury, pesticides, moisture, and lipids. Analytical results for trace elements, total mercury, moisture, and lipids were variable.” In this instance, the minnow was an indication of different levels of toxins in the river at different points; Animal size, diversity and population can also demonstrate the quality of water.

Microorganisms are very powerful biomonitors, although there is still much to be learned about their interactions with water bodies. Bacteria, algae, fungi, protozoan, and cyanobacteria are the most widely indicative species of water quality. The diversity of the microorganisms and their growth rate can indicate a variety of changes in an ecosystem. Simply the presence of some bacteria can indicate pollution, for example //E. coli// is commonly found in conjunction with fecal matter. Such organisms are known as direct indicators of pollution and poor water quality. There are also response indicator microorganisms. These biomonitors are seen when a system is overloaded with organic matter. This food, or substrate is fed on by microorganisms and in the process of decomposing the organic matter, the organisms consume vast quantities of oxygen, turning the system from aerobic to anaerobic which along with decreased dissolved oxygen can produce ammonia and hydrogen sulfide which are detrimental to water quality. Microorganisms can also respond physiologically. Many bacteria move through a process known as chemotaxis, they move toward or away from chemicals (Prescott, 2011). Microorganisms also respond to very low concentrations of pollutants and can indicate this through secreting stress proteins. A study by A. Blom et al in 1992 demonstrated that //E. coli// was extremely sensitive to environmental pollutants. They exposed the bacteria to nine different chemicals and monitored their growth rate and stress proteins. “It is evident that stress protein synthesis is a more sensitive index of stress than growth rate, since pollutant concentrations at which little or no growth inhibition occurred evoked stress protein synthesis”( Blom, Harder, & Matin, 1992 ). This study illustrates that microorganism are perceptive and perhaps proactive indicators of water quality due to their ability to adapt to stressors, or pollutants.

Plant indicators are vegetation or vegetation like organisms that indicate the health of an ecosystem. They comprise of a variety of vegetative growth from trees, shrubs and grasses, to mosses, bark and algae. Plant indicators are most commonly used to evaluate air quality and air pollution, due to the fact that plants photosynthesize, however, they are a good indicator of water quality as well, for example:
 * Turbidity- If the water is not clear enough, sunlight may not penetrate and plants are unable to get energy.
 * Temperature- Certain vegetation may overgrow a system if the water is too warm, while others may expire if the water is too shaded or cold.
 * Nutrient concentrations- As with any food source, balance is essential. If the nutrients are inadequate, vegetation starves, whereas an excess of nutrients results in overproduction and the system may "choke" so-to-speak.

A study by Liam Morrison in 2006 used brown seaweed as a bioindicator of metal contamination in coastal regions off of Ireland. Several sites were chosen based on possible contamination by humans via boats, metals and municipal sewage discharge. Samples were collected from these sites and evaluated. It was found that high levels of Chromium, Cobalt, Lead and Cadmium were found in samples and that “In general, variations in seaweed metal concentrations were site-specific with little seasonal variation observed, and the temporal and spatial patterns that existed could relatively readily be related to seaweed growth rates and anthropogenic activity.” ( Morrison, Baumann, & Stengel, 2008 ).

Biological indicators are effective quantitative ways of measuring water quality. They are being monitored in water bodies throughout the world and a movement towards using biomonitors in river restoration and as indicators of a rivers overall health is becoming more popular.

= IMPACTS ON WATER QUALITY = = Designated Uses = In order to prevent water bodies from becoming polluted, the establishment of the Clean Water Act and the NPDES use water quality standards and discharge limits to restrict pollutants. These restrictions enable States and Indian Tribes to specify appropriate water uses. Those uses can be for drinking water supply, protection of fish and wildlife, for recreation, agricultural and/or industrial use, or for navigational purposes. These purposes are identified and the correct standards to achieve those purposes are established. Once established, those purposes must be protected. For water bodies that aren’t at least designated as fishable/swimmable are identified and analyzed to see if that designated use can be attained. = = = **State of Streams in the U.S.** = According to a Pennsylvania Department of Environmental Protection (DEP) water quality assessment report, 43% of their streams and rivers have been assessed for water quality in the U.S. and one-fifth of those are considered impaired or degraded (impaired meaning any one of its designated uses is not being met). They have more than 83,000 miles of streams and rivers. While some of these still have fish, they “no longer sustain aquatic communities that should be present.” The impairment and degradation is attributed completely to pollution. This is just one state in the U.S.

The U.S. Environmental Protection Agency maintains a “[|Watershed Assessment, Tracking & Environmental Results]” on their website; according to it, miles of impaired waters equals 514,795, and only represents 27.5 percent of total waters in the U.S. And more than 53% of those are impaired! There are also 6,369 miles of threatened waters (all of their designated uses are being met but at least one is in danger of not being met). The total assessed waters equal 970,781 miles (there are still 3,533,205 unassessed miles of streams and rivers). New Mexico has 196 impaired waters.

= ECOLOGICAL RESTORATION TECHNIQUES = It is helpful to understand the relationship between restoration techniques and the impact on water quality parameters. This understanding helps determine when restoration can be used to improve water quality and which technique addresses the particular water quality issue.

= Structural Complexity = A river that flows rapidly will have a turbulent surface, with much more surface area for oxygen to diffuse across than a flat, slow moving river. The atmospheric pressure drives more oxygen into the water. Also, the turbulence created by churning waters then causes air to hit the water at a high pressure, allowing more oxygen to become dissolved. This is aeration of water. Adding drop structures or inserting boulders adds complexity to a water body giving it more opportunities to diffuse oxygen and also to provide more habitats for fish. By reworking a stream channel to have more sinuosity or meandering to mimic natural flow patterns may be helpful to channelized waters, though it can slow down water; it will promote recharge and still maintain areas of turbulence for oxygen diffusion. In the same way, dams and other flow diversions can be operated to more closely simulate natural flow conditions.

= Restoring Wetlands  = Restoring wetlands is another technique which addresses many water quality issues. Wetlands intercept sediment. If they intercept acids, wetlands neutralize acidity by trapping acids in their sediment. In the same way, wetlands can intercept nutrients reducing unwanted plant growth in the stream. Wetlands will then serve as natural storage for water which in turn can restore natural hydrological regimes (habitat for fish and wildlife) and improve water quality to the stream.

= Riparian Vegetation/Exotic Plants = Riparian vegetation can impact a river in various ways. Restoration efforts to promote riparian vegetation must understand the methods that vegetation uses to improve water quality in order to implement restoration techniques in an effective manner.

In “The Role of Riparian Vegetation in Protecting and Improving Chemical Water Quality in Streams”, Dosskey outlines four ways in which riparian vegetation affects water quality. Through direct chemical uptake, plants manipulate nutrients and pollutants. The live tissue, such as leaves, stems, and roots store nutrients and this ability varies with the age of the vegetation. Vegetation can uptake many metals and organic pesticides, transforming and degrading them in the plant tissue. Riparian vegetation can also impact water quality in an indirect manner; they supply chemically active detritus. Through the decomposition of leaf litter and other organic matter, organic chemicals enter the soil. The soil then traps these chemicals and microorganisms and the soil break these compounds down further. This reaction consumes oxygen and the microbes transform from aerobic to anaerobic. They then begin feeding on nutrients such as nitrogen and phosphate, resulting in less nutrient seepage into the stream. A second indirect impact of riparian vegetation on streams is the ability to modify water movement. Vegetation creates roughness and therefore mediates flow. With less velocity water has more time to infiltrate. Vegetation growing in the river or fallen limbs may slow the flow of water through the streambed resulting in less channelization. Finally, vegetation stabilizes soil. Erosion is evidence of a degraded river system. It is detrimental to the stream not only because of sediment loads, but because the soil that may slough into a water body is often chemically laden. This nutrient rich soil results in chemical loads in the stream and pollutes the system. Riparian vegetation root systems mitigate erosion by aiding in cohesion. With less erosion there is channel aggradation, more bank stablitity, and a possible increase in the connectivity between the river and riparian zone ( Dosskey et al., 2010 ).

Dosskey et al. emphasize that the ability for riparian zone restoration varies with the type of pollutant in the system, the degree of degradation and the type of vegetation used. However, it is strongly believed that a healthy and active riparian zone is necessary in river restoration.

Below, are examples of ecological restoration techniques and the water quality characteristic the technique improves:

**Table 2: Restoration Technique Matrix**
 * < **Ecological Restoration Technique** ||= **Stream** **Morphology** ||= **Sediment** **Loads** ||= **High** **Flows** ||= **Low** **Flows** ||= **Algal** **Growth** ||= **DO** ||= **Temp** ||= **pH** ||= **Ammonia** ||= **Metals** ||
 * < Structural complexity, sinuosity and meander ||=  ||= • ||=   ||= • ||=   ||=   ||= • ||=   ||= • ||= • ||
 * < Insert drop structures to create turbulence ||=  ||= • ||=   ||=   ||= • ||= • ||= • ||=   ||= • ||= • ||
 * < Mitigate upland use ||=  ||= • ||=   ||=   ||=   ||=   ||=   ||=   ||=   ||=   ||
 * < Operate Dams & flow diversionsto simulate natural flow conditions ||=  ||= • ||=   ||=   ||=   ||=   ||=   ||=   ||=   ||=   ||
 * < Restore wetlands to intercept sediment ||=  ||=   ||= • ||=   ||= • ||= • ||= • ||=   ||= • ||= • ||
 * < Manipulate discharge from reservoirs to increase fine sediment ||=  ||=   ||= • ||=   ||=   ||=   ||=   ||=   ||=   ||=   ||
 * < Increase substrate roughness ||=  ||=   ||=   ||= • ||=   ||= • ||= • ||=   ||= • ||= • ||
 * < Promote growth of riparian vegetation,replace exotic plants ||=  ||=   ||=   ||= • ||= • ||= • ||= • ||= • ||= • ||= • ||
 * < Land-use modifications ||=  ||=   ||= • ||= • ||=   ||=   ||=   ||=   ||=   ||=   ||
 * < Plunge pools and flow baffles ||=  ||=   ||=   ||= • ||=   ||=   ||=   ||=   ||=   ||=   ||
 * < Reduce channelization ||=  ||=   ||=   ||=   ||= • ||=   ||=   ||=   ||= • ||=   ||
 * < Reduce imperviousness in recharge areas,increase infiltration ||=  ||=   ||=   ||=   ||= • ||=   ||=   ||=   ||=   ||=   ||
 * < Increase channel depth and undercut banks ||=  ||=   ||=   ||=   ||=   ||= • ||= • ||= • ||= • ||= • ||
 * < Nonpoint control of nutrient loading ||=  ||=   ||=   ||=   ||=   ||= • ||=   ||=   ||=   ||= • ||
 * < Retrofit dams with multilevel intakes ||=  ||=   ||=   ||=   ||=   ||=   ||=   ||= • ||=   ||=   ||

= EXAMPLE = Chesapeake Bay was one of the first water systems deemed severely impaired by the CWA, with areas classified as “dead zones”. These zones are locations where algae have overgrown to the point that they have consumed the waters dissolved oxygen, or become hypoxic. “Hypoxia occurs … when oxygen concentrations fall below the level necessary to sustain most animal life. Hypoxia results when oxygen consumption, primarily through decomposing organic material, exceeds oxygen production through photosynthesis and replenishment from the atmosphere.” - Mississippi River/Gulf of Mexico Watershed Nutrient Task Force, 2004 (http://toxics.usgs.gov/definitions/hypoxia.html). The main contributor to hypoxic systems is nutrient pollution, namely nitrogen, which algae thrives on, invades the system, and creates an unsustainable environment for any other organisms. Along with the EPA, the states surrounding the bay and contributing waters formed a restoration organization known as the Chesapeake Bay Program and signed The Chesapeake Bay Agreement of 1983. This agreement outlined goals of reducing pollution in the bay. The EPA mandated TMDLs of nitrogen and phosphate (the two major nutrient pollutants in the bay). Because of the Chesapeake Bay Agreement, The Chesapeake Bay Program Executive Council was formed. This council is responsible for monitoring pollution levels in the bay and informing the public. They are also in charge of coming up with and expanding upon Water Implementation Plans (WIPs), in which they assess and make decisions on how to ensure pollution reduction. The states comprising the Council are:
 * Chesapeake Bay **


 * Virginia
 * Pennsylvania
 * Maryland
 * District of Columbia
 * Delaware
 * New York
 * West Virginia

Current State of Chesapeake Bay
The Chesapeake Bay has long held the stigma of being severely polluted. With the implementation of the Clean Water Act, much of the pollution has gradually decreased, particularly from wastewater treatment plants due to monitored effluent and TMDLs. Unfortunately the Bay is still teaming with contaminants, with the beaches being regularly closed in the summer due to high fecal colliforms, but there are also other dangerous organisms. In 2009, the Chesapeake Bay Foundation published a study entitled “Bad Water 2009: The Impact on Human Health in the Chesapeake Bay region”. Water pollution was no longer viewed as a government problem, but also as an issue that affected the individual resident and in turn that he or she could impact. “The need for decisive action can no longer be ignored, because it not just the Chesapeake’s oysters and fish that are threatened by the effects of pollution and bacteria, but our people as well.” The publication discussed five contributors to human health issues that are influenced by pollutants. “This report clearly identifies pollution related human health risks that need to be corrected. Does it mean that one should never swim in local rivers or the Bay? No. But the fact these problems exist, and that solutions are available, is an indictment of EPA’s enforcement of the Clean Water Act and underscores why we filed a lawsuit to force change.” - Will Baker, President, Chesapeake Bay Foundation Because of this study, people are more educated about their action and the impacts they have on the Chesapeake Bay as well as the risks if the pollution continues. The multiple authors of this report agree that, “Cleaner water will mean not only a healthier environment; it will also help ensure healthier swimmers, boaters, anglers, and rural families.” Since its establishment, progress has been made as illustrated in the following charts from the [|ChesapeakeStat] website:
 * **Vibrio**- These are bacteria that live in salt water and can cause intestinal problems if ingested. Humans are exposed by eating shellfish which have fed on Vibrio. The main contributor to an increase in Vibrio populations within the Bay is temperature increases.
 * **Cyanobacteria**- Cyanobacteria are similar to algae. They photosynthesize and thrive in high nutrient conditions. Due to stormwater runoff and excess fertilizer, these bacteria have proliferated in areas of the Bay that are low in salinity. They produce toxins that are responsible for kidney and liver damage in humans.
 * **Cryptosporidium**- When ingested, these bacteria cause diarrhea and other sever infections. They are present in fecal matter and can enter the bay from leaking septic systems.
 * **Mercury**- While not an organism, mercury is highly toxic and can cause neurological damage. Humans may ingest it by eating shellfish that have been exposed. Industrial sites, such as power plants are a common source of mercury pollution as well as improper disposal of hazardous waste.
 * **Nitrates-** Nitrates can be hazardous to humans when ingested at more than 10mg of Nitrate per liter of water. People in the Chesapeake area are exposed to nitrates in their drinking water. Fertilizer heavy in nitrates leaches through the ground and contaminates the wells.



Figure 11: Current and Target Phosphorous, Nitrogen,and Sediment and Loads on the Chesapeake Bay

As of 2010, The Chesapeake Bay water quality has improved, yet it is still rated as “dirty water” according to the EPA. A [|State of the Bay Report (2010)] outlines the health of the Chesapeake Bay, rating it at 31% of its condition in the 1600s. It breaks down the bay into three categories, compares them to levels from 2008 and elaborates on how to make improvements to these areas.

**Methods for Improvement**
The overall consensus for how to continue to improve the quality of the Bay and meet the goals outlined in the agreement is:
 * manage point source pollution (stormwater runoff, wastewater treatment plants)
 * monitor land use
 * restore buffers (riparian forests and wetlands)
 * monitor and enforce TMDLs
 * effectively execute WIPs

Executive Order 2012
In an effort to further impact the water quality of the Chesapeake Bay, an [|executive order] was administered for review in March of 2012. This order outlined several goals: **Restore clean water** **Recover Habitat** **Sustain Fish and Wildlife** **Conserve Land and Increase Public Access**
 * “Reduce nutrients, sediment and other pollutants to meet Chesapeake Bay water quality goals for dissolved oxygen, clarity, and chlorophyll-a and toxic contaminants.”
 * “Restore a network of land and water habitats to support priority species and to afford other public benefits, including water quality, recreational uses and scenic value across the watershed.”
 * “Sustain healthy populations of fish and wildlife which contribute to a resilient ecosystem and vibrant economy.”
 * “Conserve landscapes treasured by citizens to maintain water quality and habitat; sustain working forests, farms and maritime communities; and conserve lands of cultural, indigenous and community value. Expand public access to the Bay and its tributaries through existing and new local, state and federal parks, refuges, reserves, trails and partner sites.”

While the Chesapeake Bay remains an impaired system, it has come a long way from when the Clean Water Act was first administered. Through the EPAs involvement in monitoring TMDLs into the Bay and the Chesapeake Bay Program creating a public interest, realistic goals have been set for the further [|restoration of the Bay]. By the year 2025: The Chesapeake Bay is an example of how extremely poor water quality can be improved through legislative action coupled with public enthusiasm.
 * Nitrogen loads will be reduced by another 75.39 million pounds
 * Phosphorous loads will be reduced by 4.68 million pounds
 * Sediment loads will decrease by 1334 million pounds

= WATER QUALITY AND THE RIO GRANDE = The Rio Grande has gone from a multi-channeled, multi-thalwag river into a single channel. The development to that of low sinuosity meandering channel is due to reduction in peak flow magnitudes. Jetty jacks and vegetation (native and non-native vegetation) have been stabilizing banks limiting lateral movement and eliminating sediment. The channel width has also narrowed both naturally and artificially to increase the “efficiency” of flow conveyance. Grade control, both natural and artificial, is associated with surface exposure of hard rock, coarse sediment from arroyos and diversions for irrigation. Suspended sediment loads have decreased; even sediment contributions from the Rio Puerco have had a notable decrease. This is attributed to better land management practices, reforestation, fire suppression and natural storage of sediment in arroyos. It is thought that as conditions get drier or conditions of severe drought occur that there will be an increase in sediment production. The bed characteristics tend to be fine textured downstream of Cochiti ranging from mostly sand to clay and silt. Closer to diversion structures or higher grade areas the beds are usually more cobbled or graveled.

TMDLs
Water quality is degraded in the Rio Grande River by municipal, industrial and agricultural discharges. Elevated water temperatures and depletion of dissolved oxygen in pools is being associated with the drying river. However, the New Mexico Department of Health and the New Mexico Environment Department have both stated that from summarized results of USGS water quality studies, and that while it found pesticides, those concentrations were only slightly above detection limits. As with most municipal streams, potential effects on aquatic organisms from pharmaceuticals, antibiotics, hormones and related chemicals, as well as caffeine, are still a concern for treated wastewater.

TMDLs for the Rio Grande are chlorine concentration limits are less than or equal to 0.013 mg/L b ecause of silvery minnow conservation. C oncentration of ammonia, as nitrogen, (at 25 °C and pH 8) is less than or equal to 3.09 mg/L for larvae.

Restoration
Restoration activities include water conveyance efficiency, fish and wildlife habitat improvement, fire hazard reduction, recreation enhancement, ecosystem recovery, water conservation, grazing improvements, and cultural considerations. Though none of these objectives say “improves water quality” directly, most of these activities would improve water quality indirectly.

Passive strategies utilize the natural processes of the river as they currently exist under the management and climatic conditions. Examples of passive restoration techniques include the removal of lateral confinements that restricts changes in the channel location and the cessation of channel maintenance practices that are counter to the natural tendency of the river processes.

Active restoration techniques (see below), such as protecting streambanks to promote the colonization of stabilizing riparian vegetation (Gordon et al., 1992), or in contrast, destabilizing banks to counter the adverse effects of channelization, channel incision, and disconnected floodplains.

SPECIFIC TECHNIQUES: · Bank lowering: removal of vegetation and excavation of adjacent soils to main channel to enhance potential for overbank flooding. This would foster native plant growth and provide shallow aquatic habitat. The effect on water quality: eventually, lower temperature. · Ephemeral side channels: low gradient, flow-through channels connected to the main channel. It’s intended to carry flow away from the main channel during high-flow events. Designs include wetlands and pools. The effect on water quality: increase DO, stabilize pH. · Bank-line embayments: rather than a discrete inlet, it exchanges water with the main channel across a broad section of bankline. These areas retain organic debris. The effect on water quality: increased DO, stablize pH. · Arroyo channel reconnection: may locally increase water and sediment supply and is often an area of eddying. The effect on water quality: increased DO ,stabilize pH. · Channel widening: intended to reduce average flow velocities and to develop more diverse channel and floodplain features if islands and bars form. It is hoped to develop a greater variety of aquatic habitats. The effect on water quality: increase DO, stabilize pH. · Removal of lateral confinements: reduce or eliminate structural features and maintenance practices that decrease the potential for the channel to erode its banks and have a more diverse channel and floodplain features. The effect on water quality: increase DO. · River bar and island enhancement: it should increase variety of aquatic habitat by creating more complex channel configurations, including backwaters, shear zones and convergent and divergent eddy zones. The effect on water quality: increase DO, stabilize pH. · Destabilization of island and bars: to produce wider channels. The effect on water quality: stabilize pH. · Gradient control structures: to create diverse velocities and flows, to stabilize or raise the riverbed. It can be an artificial “hard point” that reduces or eliminates scouring, down-cutting and entrenchment of the river channel. It indirectly increases channel stability. The effect on water quality: includes trapping fine sediment, thus stabilizing pH. · Woody debris: includes outing trees, stumps, large branches, root wads, etc. into the channel or near the banks to create localized aquatic habitats. The effect on water quality: stbilize pH.

= CONCLUSION = Ecological restoration techniques directly address physical needs of a stream; however, what we see is that the technique also indirectly contributes to better water quality. For example, a channelized stream might be restored to a more natural meander to slow down flow to reduce scouring of its banks. At the same time, this causes some areas of turbulence at its bends which in turn improves diffusion of oxygen in the water. What we find is that a more complex system-meandering versus straight channeling, drop structures, diverse vegetation and aquatic life-lends to opportunities for a stream to reach its own equilibrium or ability to self-stabilize and maintain its natural water quality. It is the overloading of pollutants and manipulation of a stream away from its original design that leads to issues of poor water quality whether that be upstream mining or channelization. These manipulations or changes cannot be made without providing some other compensating structure or change to allow a stream to rebalance itself. Tracking and understanding water quality parameters allows one to monitor impacts on a stream and to use proper restoration techniques on streams that have been damaged.

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