Archive for February, 2011February 25, 2011
Nitrate itself is generally not a concern with respect to human health. However, bacteria and other substances in the human body can transform nitrate from drinking water into nitrite, which can then be transformed into nitrosamines. Nitrosamines are compounds formed by the reaction between nitrite and secondary amines; they are also found in trace amounts in some processed fish and cured meats. Nitrite and nitrosamines have been shown to adversely affect human health. This is why the federal government regulates nitrate and nitrite levels in public drinking water supplies.
Blue-baby syndrome (methemoglobinemia) (rarely diagnosed in the U.S.) is caused by exposure to elevated levels of nitrite in infants less than 6 months old. Nitrite adversely affects the blood’s ability to carry oxygen, which can result in a bluish color in the infant’s skin. If not treated, blue-baby syndrome can be life threatening. Possible risk factors for blue-baby syndrome include nitrate in drinking water, some genetic conditions, and certain intestinal infections.
Research is ongoing on the possible association between exposure to nitrate in drinking water and the risk for certain cancers. In the body, the transformation of nitrate to nitrite to nitrosamines can occur; nitrosamines have been shown to be carcinogenic (cancer-causing) in laboratory animal studies. Conflicting results from studies on human exposure to nitrate in drinking water and risks for cancer have been reported in the scientific literature.
Q. How much nitrate in drinking water is safe?
The U.S. Environmental Protection Agency (EPA) regulates nitrate and nitrite based on concerns related to blue-baby syndrome. The maximum contaminant level (MCL) for public drinking water supplies is set at 10 mg/L** for nitrate nitrogen and the MCL for nitrite nitrogen in public drinking water supplies is set at 1 mg/L. Public water supplies cannot exceed these MCLs. Private well water is not regulated.
** 1 mg/L (milligram per liter) = 1part contaminant per million parts of water. One part per million is equivalent to a single penny in ten thousand dollars.
Q. Is water the only source of nitrate to which humans are exposed?
No. Nitrate also occurs naturally in the environment, is found in many vegetables and some processed meats, and is produced naturally within the human body. Nitrate from drinking water accounts for between 15% – 75% of a person’s exposure to nitrate from environmental sources. The higher the nitrate nitrogen level in water, the greater the overall contribution. In addition, many vegetables and fruits contain substances (such as vitamins C and E) that inhibit the transformation of nitrate nitrogen to nitrite to nitrosamines. This “protective factor” may lessen the contribution of nitrate from vegetables that is vailable for conversion to nitrite in the digestive system.
Q. What can I do about nitrate in my drinking water?
Nitrate levels in municipal and other public water supplies are required to be within federal standards. This includes regular monitoring and testing drinking water supplies. If you have a private well, you should have your water tested on a regular basis (every one- two years). Boiling water increases the nitrate concentrations. Certain types of in-home treatment systems will remove nitrate, but they must be maintained regularly to protect public health. If you have health concerns about nitrate in your water, talk to your doctor. For information on public programs, contact your local health department or your county sanitarian. There are state funded programs for evaluating the susceptibility of private wells to contamination (Farm*A*Syst) and for private well water testing (Grants to Counties). Information can be found on the web at www.uhl.uiowa.edu (on this site select publications) and www.epa.gov/ogwdw where you can find facts sheets on drinking water quality and water quality programs.
For more information, call Des Moines Water Works at (515) 283-8700 or visit www.dmww.com.
Developed in consultation with Agribusiness Association of Iowa, Cedar Rapids Water Department, Center for Health Effects of Environmental Contamination-University of Iowa, Des Moines Water Works, Iowa Association of Water Agencies, Iowa Corn Growers Association, Iowa Soybean Association, Iowa State niversity Extension, and U.S. Dept. of Agriculture-National Soil Tilth Laboratory.
Want more Just the Facts? Visit: http://www.dmww.com/SubPageHTML.aspx?SubPageID=120Labels: Des Moines Water Works, Des Moines waterworks, DMWW, Nitrate, Nitrates, water quality Posted in Health, Water Quality, Water Treatment February 21, 2011
Most of us go to the faucet for a glass of water and don’t think a thing about it, like how it got there or what it cost for the glass of water. The only time we really give it much thought at all is when we receive our monthly “water bill.”
If I asked you how much you pay for water each month, what would you tell me? About $65? Did you know the average customer in Des Moines pays only $16 or $17 a month for all the water they use inside their home? Water service is perhaps the greatest bargain in my home month after month. I cook with it. I drink it. I bathe my kids in it. I toil through loads (and loads!) of laundry with it. It doesn’t run out, and I don’t have to run to the store to get it. It makes my life simple, all month long, for only $16.
It’s easy for us to forget water is such a great bargain, because our “water bill” runs higher than that every month. That’s because the Des Moines Water Works statement you receive has other services on it besides water–other services that also make your life convenient and easier. Here’s a run-down of your bill (see example bill statement below):
Water charges (A) – The cost of water is typically half the total on your monthly “water bill.” Water charges are determined based on the amount of water you use and the water rate per thousand gallons as established by the DMWW Board of Trustees. In addition to this volume charge, each customer pays a flat availability fee each month of $5.00. This covers fixed costs, such as the cost of the meter inside your home, the statement you receive each month, the pipes and mains that bring the water to your home, etc. You can find the amount of water consumption at the bottom of your statement each month (B). Because of the types of meters DMWW uses, water consumption is shown in cubic feet. If you want to know how many gallons you use a month, multiply your consumption in cubic feet by 7.4805. For example, a typical 2-person household uses 500 cubic feet, or 3,740 gallons each month.
City charges – The City of Des Moines contracts with Des Moines Water Works to bill for City charges, including sewer, stormwater, and solid waste.
- Like water charges, sewer charges (C) are based on the amount of water you use each month (the water you use in your home eventually goes through the sanitary sewer system as it leaves your home), but the rates are set by the City of Des Moines. There is also a flat customer service charge for fixed costs associated with the sanitary sewer system.
- Solid Waste charges (D) reflect the cost of curbside garbage removal inside the City of Des Moines.
- Stormwater charges (E) are paid by all City residents to provide funding for the maintenance of existing stormwater facilities and for the construction of new facilities to accommodate stormwater run-off.
City ordinance requires that property owners pay non-metered charges (sewer customer service charge, stormwater, and solid waste) when the service is available, regardless if a property is inhabited or the service is used.
Understanding your water bill is key to understanding and appreciating the value of water service delivered right to your faucet. As for me? I wouldn’t want to live without it…even if it meant getting out of doing laundry.
Copper is the major component of most home plumbing. In the past, lead was used as the major constituent of certain types of pipe. It was also used in pipe solder, and it can be present in trace amounts in the alloys that are used in the production of plumbing fixtures.
Q: How can lead and copper contaminate my drinking water?
Through the corrosion of plumbing systems. Lead and copper are not found in the treated water. Corrosive (soft) water is more aggressive than hard water and may leach lead or copper out of the plumbing in your house, allowing these minerals to get into your tap water. Our treatment process removes just the right amount of hardness from the water so it creates a thin layer of protective scale to coat your pipes and protect them from the corrosion.
Q. How does Des Moines Water Works test for lead and copper?
We test for lead and/or copper using atomic absorption spectroscopy. Simply put, we measure the amount of energy absorbed at a wavelength (color) specific to the lead and/or copper.
Q: How does Des Moines Water Works treat for lead and copper?
During the treatment process, we keep the water leaving the plant near a 9.5 pH level to form a thin barrier of protective scale in the pipes.
Q: What are the health effects?
In infants and children, lead may cause delays in physical or mental development. In adults, it may cause kidney problems and/or high blood pressure. Excessive amounts of copper can cause stomach upset and liver and kidney problems.
For more information, call Des Moines Water Works at (515) 283-8700 or visit www.dmww.com. For additional information, call the SAFE DRINKING WATER HOTLINE: 1-800-426-4791
Want more Just the Facts? Visit: http://www.dmww.com/SubPageHTML.aspx?SubPageID=120Labels: Des Moines Water Works, Des Moines waterworks, DMWW, Lead and copper, water quality Posted in Health, Water Quality, Water Treatment February 17, 2011
The warm temperatures this week have melted most of the snow and increased river flow of Raccoon River. Ice chunks as thick as 16 inches could be seen tossing and churning in the powerful river currents as the water slowly broke up large masses of ice and washed them downstream through Water Works Park. There were no reports of ice jams in the City as of 2:00 pm. However, a jam could occur if the ice chunks build up behind bridge piers at Fleur Drive and other downstream bridges.
Municipal tap water in the United States is some of the safest water you can drink. You can go to nearly any city in the country and drink the water without giving its safety a second thought. Nonetheless, many people choose to spend more for bottled water, or to purchase home treatment devices that will presumably modify tap water in a positive way.
No scientific study has ever concluded that bottled water is safer than tap water. According to the National Resources Defense Council (NRDC), bottled water regulations are inadequate to assure consumers of either purity or safety. The Food and Drug Administration is responsible for bottled water safety, but the FDA’s rules completely exempt waters that are packaged and sold within the same state, which account for 60-70% of all bottled water sold in the United States. Even when bottled waters are covered by the FDA’s rules, they are subject to less rigorous testing and purity standards than those which apply to city tap water, which is regulated by Environmental Protection Agency. NRDC testing evaluated 1,000 bottles of 103 brands of bottled water. While most of the tested waters were found to be of high quality, about one-third of the waters tested contained levels of contamination – including synthetic organic chemicals, bacteria, and arsenic.
What about home treatment devices? Some devices can cost hundreds or even thousands of dollars, and some result in a large water waste as high as 40%. Some will treat the water for the entire dwelling, some for one particular tap (kitchen, typically) and some for a receptacle such as a pitcher of water. A myriad of filters are available, and you should educate yourself and decide what your specific objectives are before purchase. It is important to keep in mind that all home water treatment devices need regular maintenance to operate effectively. For example, if filter cartridges are not changed on a regular basis, they can actually begin to harbor odors and tastes, bacteria and other contamination that will actually diminish the quality of the tap water.
- Take unused, unneeded, or expired prescription drugs out of their original containers and throw them in the trash.
- Mixing prescription drugs with an undesirable substance, such as used coffee grounds or kitty litter, and putting them in impermeable, non-descript containers, such as empty cans or sealable bags, will further ensure the drugs will not enter lakes, streams and aquifers.
- Flush prescription drugs down the toilet only if the label or accompanying patient information specifically instructs doing so.
- Take advantage of community pharmaceutical take-back programs that allow the public to bring unused drugs to a central location for proper disposal. Some communities have pharmaceutical take-back programs or community solid-waste programs that allow the public to bring unused drugs to a central location for proper disposal. Where these exist, they are a good way to dispose of unused pharmaceuticals.
The FDA advises that the following drugs be flushed down the toilet instead of thrown in the trash:
Actiq (fentanyl citrate)
Daytrana Transdermal Patch (methylphenidate)
Duragesic Transdermal System (fentanyl)
OxyContin Tablets (oxycodone)
Avinza Capsules (morphine sulfate)
Baraclude Tablets (entecavir)
Reyataz Capsules (atazanavir sulfate)
Tequin Tablets (gatifloxacin)
Zerit for Oral Solution (stavudine)
Meperidine HCl Tablets
Percocet (Oxycodone and Acetaminophen)
Xyrem (Sodium Oxybate)
Fentora (fentanyl buccal tablet)
Note: Patients should always refer to printed material accompanying their medication for specific instructions.
For more information, call Des Moines Water Works at (515) 283-8700 or visit www.dmww.com.Labels: Des Moines Water Works, Des Moines waterworks, Disposal of Prescription Drugs, DMWW, water quality Posted in Customer Service, Health, Water Quality February 10, 2011
Water from our rivers is “hard,” meaning it has a high mineral content, especially calcium and magnesium. This is because 100 million years ago, what is now Iowa, was under the surface of the ocean, and large limestone deposits are the result. As rain water and snow melt trickles through the limestone, toward shallow groundwater and eventually into our streams, it dissolves mineral deposits. Hardness is reduced in DMWW’s treatment plants using a process called lime softening.
The river water has a high nutrient content, especially nitrate-nitrogen and phosphorous. Some of the fertilizer used for crops is washed away or enters the streams through agricultural drainage tiles. Our super-rich soils also contain a lot of natural nitrogen and phosphorous, which is liberated from the soil during cultivation. The Raccoon and Des Moines Rivers have the highest and second-highest nitrate concentrations of the 42 largest Mississippi River tributaries. DMWW operates the world’s largest nitrate removal facility at its Fleur Drive Plant.
Our rivers have a relatively high level of sediment. Erosion is a natural process that has been greatly increased by both rural and urban land uses. It’s likely that most Iowa streams ran much clearer prior to settlement than in the present day. Loss of native perennial vegetation and increased streamflows because of human modification of natural hydrology, along with changes in land use and climate, are the primary culprits for increased erosion. In addition, levees have divorced streams from their floodplains, increasing river energy during high flows. This helps the stream scour sediment from the stream bed and banks. DMWW removes about 20,000 pounds of sediment (1,400 pounds per million gallons) from the treated river water every day, so the water will be clear and safe to drink.
Although DMWW’s source waters are considered impaired, DMWW is continuously adapting its treatment processes to deliver Water You Can Trust for Life.
Water pressure is influenced by a number of factors including ground elevation, distance from the treatment plant or pumping station, piping materials, and even water demand on any given day. Ground elevation influences water pressure because pressure is actually created by lifting water into the air above the point of use. This is why water is pumped up into water towers – to raise it above the point of use thereby creating pressure. As a result of the influence that elevation has on water pressure, higher elevations in a service area experience the lowest pressures and lower elevations experience the highest pressures. Ground elevations in Des Moines range from 800 feet above sea level on the east side of the City near the Des Moines River to more than 970 feet above sea level in northwestern areas of the city. This 170 feet of elevation difference represents a water pressure variation of 75 pounds per square inch (psi). The distance from the pumping station and changes in water demand introduce additional pressure variation resulting in the potential for significant pressure differences across the city. Des Moines Water Works (DMWW) manages water pressure using pressure zones, water towers and booster pumping stations, like the new booster station near the Des Moines Airport.
The City of Des Moines is divided into four pressure zones. Each pressure zone has dedicated pumping stations that pump water into the zone to maintain pressure. Water towers help stabilize pressure in some zones. Water flows into the towers during hours of the day when there is less water demand and flows back out to satisfy higher demands. The combination of water from the pumping station and water flowing out of the water tower acts to stabilize pressures in the zone.
Water pressure in the Des Moines system averages 50 psi but ranges from 35 psi to more than 100 psi depending on the location in the city. Thirty five psi is Water Works Board established minimum system pressure in Des Moines. Plumbing code requires that residential properties in areas with water pressure in excess of 80 psi be protected by pressure regulators installed on the water service lines.
Older, smaller diameter service lines or corroded service line components such as valves or couplings can cause low pressure for some customers. Currently, DMWW Rules and Regulations require that new residential service lines be installed using one-inch diameter copper or cross-linked polyethylene (PEX) pipe. Historically, ¾-inch or even ½-inch pipe was used and in some cases the pipe was galvanized steel which is subject to corrosion when buried. Homes with smaller diameter service lines, especially those with ½-inch galvanized pipe service lines, may experience low pressure due to restrictions in the pipe. Galvanized steel pipe inside the home may also contribute to pressure problems as corrosion occurs on the inside of the pipes.
Customers who feel they may have pressure problems can visit with a customer service representative for more information by calling (515) 283-8700.
by Elvin McDonald, Friends of the Des Moines Botanical Center Executive Director
My office at the Botanical Center is in the North Wing, so my usual path from the parking lot is through the potting shed, past the Show House, into the tropical splendor of the Dome and finally to my desk.
One morning last October, I couldn’t help noticing an air of happiness surrounding the gardeners and volunteers as they worked. As I entered the Dome, past the orchid wall and rounded the corner, there was Charlie Brown in his pumpkin patch, a part of our Story Time in the Gardens theme. I like to think he waved at me. At this point several little kids entered the scene and squeals of happiness ensued. I couldn’t stop smiling.
Over a hundred years ago, a British prison warden observed that the men assigned gardening tasks, primarily growing vegetables, were happier, better adjusted than the others and, moreover, much less subject to recidivism–in other words, falling back into criminal behavior.
As recently as last year, the New York Times reported that horticultural therapy is proving to be one of the most effectual treatments in rehabilitating soldiers suffering physical and emotional traumas.
Gardens and gardening are in fact life enhancers for all of us. On the 2nd anniversary of September 11th I was touched by a young widow who said she was once again able to garden, to allow herself the happiness she felt when gardening. On the 10th anniversary of the Greensburg, KS, tornado a much older widow who lost everything—husband and home—recalled finding in the storm’s aftermath a lone cockscomb that had survived. She said, “It made me think I could too—and I have.”
All of us who work at the Botanical Center strive to make it a place where happiness grows. Visit us often this New Year—and be happy.
A watershed is an area of land that drains to a common point. The 3,600 square miles of the Raccoon River Watershed drains to the confluence of the Raccoon and Des Moines Rivers in downtown Des Moines. The Raccoon River rises in Buena Vista County and travels approximately 200 miles to its mouth. The mainstem of the Raccoon is known as the North Raccoon River in its upper stretches and has two main tributaries: the Middle and South Raccoon Rivers. The Middle Raccoon River begins in northwest Carroll County and flows 76 miles to join the South Raccoon near Redfield, IA. The South Raccoon River starts near the Guthrie-Audubon County line and flows 50 miles until its confluence with the Middle Raccoon. The combined flows of the Middle and South Raccoon join the North Raccoon near Van Meter, a few miles downstream from Redfield.
The watershed mainly lies in the Des Moines Lobe, a remnant of the last Wisconsinan ice age. The Middle Raccoon traces the furthest edge of glacial advance, also known as the terminal moraine. This landscape was shaped only 12,000 years ago, much more recently than the rest of Iowa. Soils are among the most fertile on earth, and 80% of the area is cultivated for corn and soybeans.
In 1844, Captain James Allen and his Dragoon explorers were first Europeans to explore the watershed. His journals describe numerous lakes scattered throughout wet and dry prairie, and bears and elk being killed for food during the expedition. A grizzly bear was spotted on the ridge that separates Beaver Creek from the North Raccoon.
No one alive today has seen the Raccoon River in its natural state. Early settlers transformed the landscape into agricultural land through removal of native plants and systematic drainage, a process that continues to this day. The prairies and wetlands of the region were largely gone by 1900. This landscape modification dramatically altered the character, appearance, and water quality of the river to the extent that the river would be largely unrecognizable to people who saw it prior to 1860.