There are nearly 55, 000 community water systems in this country, supplying water to meet the drinking needs of more than 90 percent of the U. S. population. The Environmental Protection Agency (EPA) defines a community water source as one that consistently provides water to at least twenty-five percent for at least sixty days during the course of a year. Living in Washington, D. C.
, this is a very personal issue at this point in time. Over the summer, we have dealt with serious testing on the quality of the city’s water. When picking this topic, I believed that if I research more on it, I would become more knowledgeable of its impact on my immediate family and my community. So after finalizing my research, I formed my hypothesis stating that “if 20 residents of the Petworth subdivision of Northwest Washington, D. C. live in homes that tested positive for high levels of lead in their water, then less than half of them have replaced the pies since proper notification.
But in order to understand the problems of the city’s water system, you must know the history in how the country’s water systems and standards were formed. The United States has gravitated toward a modified minimal degradation policy that incorporates a best-available-treatment (BAT) criterion. Under this particular policy, their main objective is to minimize the effects of discharges on receiving waters, but it is recognized that the extent of wastewater treatment is technically and economically constrained. Best-available-treatment treatment is defined by the type of waste under consideration.
For municipal wastewater’s BAT standard is usually considered to be secondary treatment. However, the definition of BAT is situation-dependent. If phosphorus is a limiting nutrient in the receiving water, phosphorus removal is added to the BAT requirement. The current BAT standard for phosphorus is based on precipitation and granular-medium filtration. It is important to note that the U. S.
Environmental Protection Agency has included economic feasibility as a component in determining BAT. Distillation is always a technical possibility that would produce a non contaminating or polluting discharge, but economic considerations eliminate it from consideration in most cases. Stream water quality standards are set, and wastewater discharges are not allowed to violate these standards. Requirements for wastewater discharges are set on a minimal degradation basis, and, in addition, all discharges are required to use BAT. Defining BAT is not always straightforward, and it must also be recognized that BAT changes with time.
Application of the minimum-degradation approach must be flexible, and care must be taken to ensure that protecting water quality remains as the priority rather than simply forcing all discharges to have a particular level of treatment. Contamination of originates in different ways depending on the source of the drinking water, the type of contamination, and the method of water supply delivery (i. e. type of plumbing). Groundwater, which may be used as a source of drinking water, often becomes contaminated from percolation of toxics through contaminated soil. Alternatively, contaminated runoff and direct discharges contaminate surface water, which may also be used as a drinking water source.
Drinking water may become contaminated through the leaching of lead from plumbing systems. Finally, the intentional addition of substances to treat the water supply, such as chlorine, also represent a significant source of drinking water contamination in public water supply systems. The potential dose of a toxic compound resulting from drinking water consumption is a function of consumption rate and contaminant consideration in the water. It is preferable that consumption rate be determined for the population of interest. If such population-specific data are unavailable, however, generic rates derived from relevant regional studies or national consumption surveys may be used. Consumption surveys often report averages and distributions for both “total fluid” and “total tap water” intake.
Total fluid intake is defined as “consumption of all types of fluids including tap water, milk, soft drinks, alcoholic beverages, and water intrinsic to purchased foods.” Total tap water is defined as “food and beverages that are prepared or reconstituted with tap water” in addition to straight tap water. As purchased foods and beverages are widely distributed and less likely to contain source-specific water, the use of total fluid intake rates may overestimate the potential exposure to toxic substances present only in local water supplies. Until very recently, the U. S.
EPA has recommended using default drinking water intake rates of 2 liters per day for adults. This value is a total tap water rate, as it includes drinking water consumed in the form of juices and other beverages containing tap water, such as tea and coffee. Numerous studies have generated data on drinking water intake rates that support using a significantly lower default value to represent average adult drinking water, while using 2 liters per day to represent the upper 80 th to 90 th percentile rate. Consequently, the USEPA recommends 1. 4 liters per day as the default drinking water value for adult consumption.
Health effects of a toxicological nature are measured by blood lead levels. The effects are neuro toxic, which include irreversible brain damage. Such a toxic level I reached when the blood level exceeds 100-120 ug / d L. Severe gastrointestinal symptoms are associated with the symptoms. These symptoms start to be observed in adult lead workers at blood lead levels of 40-60 ug / d L.
The subpopulation to be carefully studied is represented by children, where encephalopathy and death are registered at a starting level of 80-100 ug / d L (blood). In nonfatal cases, permanent, severe mental retardation with other neurologic symptoms is observed at levels as low as 40-60 ug / d L. Adverse health effects are noted in children with blood levels of 40 ug / d L or higher with possible risks at levels as low as 15-30 ug / d L. Legislated water quality standards are required to present misuse of the resource for individual gain.
There is no actual benefit to a corporation or a city in maintaining downstream water quality. Despite this fact, many outstanding examples exist of sound water quality management based on ethical ideas, civic pride, and philanthropic generosity. Rivers and lakes are often symbols of a community or of a region, and residents, including corporations, often have an emotional stake in maintaining their beauty and quality. However, city councils are nearly always dealing with difficult budget constraints, and corporate leaders must face stockholder’s demands for high return on investment.
Thus, if maintaining water quality is important for priority, legal constraints must be placed on degradation, or a “tragedy of the commons” will surely occur. As the public became aware of the impact of water quality on the overall quality of life, pressure was brought to bear on state and the federal legislatures to change the system. In many cases, the early leaders of the groups, concerned the changes in the environment, were dismissed as “eco freaks and Sierra Clubbers.” Recently, there is little question about the correctness of their position or about the benefits resulting from the changes these individuals and groups brought about. Considering the seriousness of the water quality problems society now faces, such as the presence of toxic materials in water supplies, nitrate buildup, acid rain, and eutrophication, it is fortunate that public concern was and remains aroused. Presently, the EPA and the District Water and Sewer Authority (DC WASA) have been concerned about lead being found in the city’s drinking water. Although most homes have very low levels of lead in their drinking water, some homes in various communities have lead levels above the EPA action level of 15 parts per billion (ppb), or 0.
015 milligrams of lead per liter of water (mg/L). The D. C. Water and Sewer Authority distributes water to residences and business throughout D.
C. for drinking, washing, fire fighting and many other uses. WASA purchases the drinking water from the U. S.
Army Corps of Engineers’ Washington Aqueduct. WASA purchases about 130 million gallons of treated water from the Washington Aqueduct on a daily basis and distributes it to the customers. WASA serves over 500, 000 residents through approximately 130, 000 metered connections in the District of Columbia through a system of 1, 300 miles of large water main pipes in the streets in a system that also includes a series of elevated and underground storage facilities, pumping and monitoring stations throughout the District. The Washington Aqueduct (WA) withdraws approximately 180 million gallons of water each day from the Potomac River at Great Falls and the Little Fairs intakes, and then treats the water at the two water treatment plants, Dalecarlia and McMillan. Important treatment processes at WA’s Dalecarlia and McMillan facilities include sedimentation, filtration, fluoridation, pH adjustment (to help control the leaching of metals like lead from service line pipes), primary disinfection using free chlorine to disinfect treated water, and finally, conversion of the free chlorine to chloramines through addition of ammonia. The chloramines residual stays in water to provide secondary disinfection as the water travels through WASA’s network of distribution system water pipes and all the way to the person’s home.
Under federal law the water supplier is required to have a program in place to minimize lead in the drinking water. In compliance with federal requirements, WA has performed an optimal corrosion control study to minimize lead in the water. The Optimal Corrosion Control Treatment (OCCT) was designated for WA by the EPA, and OCCT was implemented by WA in 1993. The OCCT requirements, a pH of 7. 4 to 7. 7 must be maintained at the entry points to the distribution system and a minimum pH of 7.
0 is to be maintained in the distribution system. The purpose of the OCCT is to control the of water and thus minimize leaching of lead or copper from lead service lines and customer plumbing into drinking water. On November 1, 2000, chloramines began to be used by the Washington Aqueduct as a disinfectant to maintain protection against microbial contamination in the water distribution system. The change in disinfectant from chlorine to chloramines was an effort to reduce the concentrations of “disinfection byproducts” called Trihalomethanes (THMs). This change was made in more stringent national standards established by EPA to further reduce their presence in the water and reduce exposure all Americans to THMs. Chronic exposure to high concentrations of THMs is considered to be potentially carcinogenic.
Since the treatment change to chloramines, there has been a significant reduction to THMs in the drinking water. Despite the city’s best efforts to control and remove lead from the water supply, lead levels in some homes or buildings can be high because service lines and internal plumbing systems can contribute lead to water delivered by those pipes. When water stands in lead pipes or plumbing systems containing lead for several hours or more, the lead may dissolve into the drinking water. That means that the first water drawn from the tap in the morning, or later in the afternoon after returning from work or school, can contain high levels of lead. To fulfill the lead service line physical replacement requirement, EPA’s regulations allow for physical replacement of the publicly-owned portion of the service line pipe or testing to make sure that tap water tests below 15 ppb at a specific number of addresses with lead service line pipes. In 2003, WASA used a combination of testing and physical replacements of service line pipes in public space (from the property line to the water main in the street) to achieve the seven percent replacement goal.
After testing also occurred during the summer of 2004, my own residence was notified of its high levels or lead located in the service line pipes. My family was appalled by the city’s lack of responsibility in notifying the community of its problems, causing our water to become a risk to our personal health. As part of my research, I was able to conduct a six-question survey asking the people about their knowledge, opinions, and possible solutions concerning the city’s water situation. Dealing with the District of Columbia as a whole would be a challenging situation to handle due to the short period of time I was set with. Instead, my thought was to analyze the residents of my immediate community, the Petworth community, to see who was under the same circumstances my family were faced with.
A vast number of responses to my survey would allow me to breakdown the responses of families with different household environments. Dealing with 20 residents in a 5 mile radius would give me reasonable results. But random visits to residents in the Petworth was not greatly recommended. My best option was to ask for assistance from my parents in notifying neighbors, family, and friends who resided in the Petworth community. I was able to hand solicit responses from the families of 4 Virginia State University students, 4 family members, and 12 associates within the 5 mile radius. Visits last week to households that participated in my voluntary lead testing survey revealed scattered clusters of well-informed residents, but the conversations indicated that more residents remain largely unaware of lead’s potential health risks.
Few said they have discussed their results with neighbors, leaving those in untested households largely unaware that nearby homes tested high. Some said they didn’t trust the water company or its motives, and many expressed a fatalistic exasperation about the problems, saying that possible water contamination ranks low among day-to-day concerns. After the problems were first publicized in late January of 2004, WASA officials said the contamination was confined to homes with lead service lines-about 23, 000 in all. But then some homes with copper service lines showed elevated levels, indicating a broader problem. City and federal officials said new rounds of testing aimed to develop a fuller picture of contamination problems throughout the city, not just in those homes believed to be served by lead lines. In some neighborhoods, the problems have caused people to alter their routines and have spurred regular community meetings of residents struggling to keep up-to-date with the evolving issue.
But even within the limited sample of homes tested in 2003, the city’s efforts to communicate the problems and possible dangers have had limited success, door-to-door visits of different neighborhoods throughout the city have shown. WASA sent its test results to those who participated late last year and early this year; however, some residents said they weren’t aware of their results until notified by the press. Some said they might have simply overlooked a mailing. Many residents said they had the impression that the problems were caused solely by the same lead service pipes that have been connected to their properties for decades-a notion reinforced by WASA for a long period of time after the problems were first publicized. These residents said they didn’t know that recent changes to the water’s chemical composition are suspected to have made it more corrosive, causing it lead to leach from pipes and fixtures into the water. Because they believed the problems were caused solely by the pipes, many adopted the same attitude: If I’ve had the same pipes for years and they haven’t hurt me yet, why be concerned now? Ernest Fitzgerald, a resident of the 600 block of Emerson St.
N. W. , and a participant in the survey, states “It doesn’t make sense to me” after testing at the high level of 41 ppb. “People have been living in the Petworth for over 50 years in some cases, and it seems like they’d be having problems if it was bad for you.
I’m wondering if WASA is just coming up with all this as a way to make money… They lie to you so much, what can you believe?” According to some residents, some test results themselves shouldn’t be believed. Many of those whose water tested high said they hadn’t talked about the results with their neighbors, and some of those neighbors said they had no idea lead problems affected their blocks. With the longer life span that is now enjoyed as a result of the contaminant of infectious diseases, the focus of drinking water’s potential dangers has moved from acute illness to chronic illness. Illnesses such as cancer and dementia, which take years to decades to develop, have become increasingly prevalent and their associations with drinking water’s contaminants, are now becoming better appreciated. At the close of the year, we are now faced with the prospect that drinking water and its contaminants may have health effects that reach beyond our own lifetimes into generations to come.
An effect on fertility has been suggested. Although this effect is not clear, government agencies and academic institutions in the city and country are looking at this issue with concern. More time, and unfortunately, more money, is needed to verify or discount this finding and hypothesis. After going into deep research with my topic, I learned that the WASA Board of Directors took the bold step of deciding to replace all lead service lines in public space in the District with a goal of accomplishing this by the end of 2010. They are now committed to remove all lead service lines in public space, and to do so at an accelerated pace. But what happens to the service lines located on the private property of the citizens? Should they be responsible for the problems caused by city’s lack of effectiveness? Most believe they shouldn’t have to replace them because they were not the ones who caused the pipes to fill with lead, but believed that it they were offered help from the city, it would be taken into close consideration.
Perhaps the most important lesson to be learned from all my research is that the maintenance of high-quality drinking water is a dynamic process that changes with the changes in science, society, and knowledge. It is also clear that any attempt to rectify these imbalances is fraught with the danger of untoward and unknown consequences. Ultimately, for there to be any improvement in their productiveness to safeguard clean water in the future, the broad public and industry must be involved, and everyone’s cooperation will be needed. BIBLIOGRAPHY – Barzilay, J. , Weinberg, W. , Eley, J.
W. , The water we drink: Water Quality and Its Effects on Health, Rutgers University Press, pigs. 29-35, 1999- Tchobanoglous, G. , Schroeder, E. , Water Quality: Characteristics, Modeling, Modification, Addison-Wesley Publishing Company, pigs. 214-216, 1987- DeZuane, J.
, Handbook of Drinking Water Quality, International Thompson Publishing, Inc. , pigs. 80-85, 1997- Olin, S. , Exposure to Contaminants in Drinking Water: Estimating Uptake through the Skin and by Inhalation, CRC Press, pigs. 43-53, 1999- web U.
S. Environmental Protection Agency (EPA) website. Information on the quality of drinking water is available at this website. – web District of Columbia Water and Sewer Authority website. Information on the quality of drinking water is available at this website. – Leon nig, C.
, Cohn, D. , D. C. Lead Issue was Debated for Months: Regional EPA Office Decided No Federal Action Was Needed, Washington Post, March 16, 2004. – Nakamura, D. , WASA Backpedaling Prompts Confusion: D.
C. Agency Changed Advice on Flushing Taps, Replacing Pipes, Health Risks, Washington Post, March 16, 2004.