MAKING GREAT WATER BETTER
New Disinfection as of February, 2004
On February 2, 2004, our water supplier, San Francisco Water Department (SFWD), converted from chlorine to chloramine as their water disinfectant. Chloramine is the combination of chlorine and ammonia. The conversion to chloramine has allowed SFWD and Mid-Peninsula Water District to increase protection of public health, while meeting stricter state and federal water quality regulations, lowering risk of bacterial contamination, and improving taste and odor.
Water disinfection with chlorine has been extremely successful in protecting water from bacterial and viral contamination and has virtually wiped out water-borne diseases like typhoid fever, cholera, and dysentery. Chlorine however, may introduce a potential health risk. When chlorine is added to the water it not only kills bacteria and viruses but also reacts with other chemicals found in the water and form new compounds known as disinfectant by-products (DBP). One group of disinfectant by-products, trihalomethanes (THM), is suspected carcinogens and may pose other long-term health effects if present at high levels. While DBP levels have been well below the regulatory level set by the Environmental Protection Agency (EPA) and the California Department of Health Services (DOHS), the switch to chloramines will reduce the level of DBP’s by one-third.
Chloramine is more stable than chlorine and will last longer in the distribution system, providing increased protection from bacterial contamination. This will benefit the Mid-Peninsula Water District and your water supply since Belmont is towards the end of the SFWD distribution system. Switching to chloramines will increase the disinfection residual in our distribution system.
Chloraminated water is completely safe for people to drink, bathe in, clean scrapes or cuts, water the garden, and for most other purposes. However, three special groups must take precautions before using chloraminated water. Kidney dialysis patients, aquarium owners, and businesses or industries that use water in their treatment process will need to remove the chloramines prior to use. Just as with chlorine, chloramine can harm kidney dialysis patients during the dialysis process if it is not removed before the water mixes with the bloodstream. People and animals that do not live in water can safely drink chloraminated water because the digestive process neutralizes chloramine before it enters the bloodstream. Two methods for dialysis patients and aquarium owners to use to neutralize chloramine are: 1) A granular-activated carbon-filtration system specifically designed to remove Chloramine, or 2) A conditioner or additive that contains a dechloraminating chemical for both Ammonia and chlorine.
For business customers the switch to chloramine may affect the chemical residual levels in your water and require your company to adjust or upgrade its current filtration system. Chloramine may also affect complex treatment systems such as reverse osmosis equipment. Although chloramine may not directly affect your products, you should contact your water treatment equipment supplier to determine if chloramine could affect your system. Not all businesses will need to make changes. The San Francisco Water Department expects the level of chloramine present in its tap water to be 2 mg/liter with chlorine to ammonia ratio 5:1. If your business requires a lower chloramine residual, there are several methods you can use to treat or remove chloramine. For example, some companies supplied with chloraminated water added additional activated carbon canisters to their filtration systems or increased the dosage of dechloraminating chemicals to remove chloramine. Your current equipment supplier can explain the specific upgrades you will need. The SFWD does not anticipate changes in the pH or temperature of the drinking water because of the conversion to chloramine. The SFWD and the Mid-Peninsula Water District recommends contacting a water treatment professional or your current equipment supplier for more information about chloramine. These advisors can review your treatment process and make recommendations on any upgrades you may need.
The most common problem associated with chloraminated water on household plumbing, pipes, and water heaters is found to occur in domestic applications such as toilet flapper valves, water heater hoses, and some sprinkler system diaphragms. Most incidents occur where the chloramine residual is highest (near the application point). Since the application points are at SFWD treatment plants and not near your homes, these problems are less likely to occur. Yet, it is important to the Mid-Peninsula Water District to inform you of these possible defects. Some indicators of a defective devise are swelling, which grossly distorts shape, surface cracking, black flakes in the water, and slugs of black water that rapidly clear. Mid-Peninsula Water District suggests that in the event that you decide to purchase any devise that is in constant contact with water for your home or business, that you confirm with the merchant that it is chloramine resistant.
For more information on the chloramine conversion, please call our offices at (650) 591-8941 or visit http://www.sfwater.org/
Protect Your Fish, Amphibians and Reptiles
Chloraminated water passes through gills, directly entering the fish, amphibian and reptile bloodstream. Chloramine must be removed as it binds to iron in red blood cell hemoglobin, causing reduced cell capacity to carry oxygen. However, chloraminated water is safe for people and animals to drink as it is neutralized by the digestive process. It is also safe to cook with, bathe in, and for other general uses.
Just like chlorine, chloramine will need to be removed from water for fish, amphibian and reptile use. The products listed below are available at fish and pet supply stores. Aquarium or pond supply professionals, published materials and pet owners recommend the following:
• Treatment products (drops or tablets) that remove both ammonia and chlorine Biological filter (for ammonia) and chemical agent (for chlorine)
• It has been reported high quality activated carbon filtration and reverse osmosis remove chloramine under optimum conditions, but are expensive and must be closely monitored to ensure their effectiveness.
• Aquarium owners will want to test their water for ammonia concentrations in addition to chlorine. A test kit with the correct active agent for ammonia can be helpful for monitoring. Two basic kits are available, and should be selectively used:
• Nessler reagent. This kit will give a faster reading, but will also give a false reading if ammonia binders have been used.
• Salicylate reagent. This kit provides an accurate reading when ammonia have been used.
• Chloramine is toxic to both fresh and salt water fish. Drinking water used with artificial sea salts for makeup water in salt water fish tanks must have the ammonia and chlorine removed first.
• Chloramine should ideally be removed from water before being added to a pond. The San Diego Koi Club suggests the following guidelines from their experience:
• If less than one percent of the total water volume of your system is replaced at any one time, the pond should absorb new chloraminated water with little to no impact on fish.
• If one to ten percent of pond water volume is replaced, sodium thiosulfate and a biological filter effectively remove chloramine.
• If more than ten percent pond water volume is replaced, an
ammonia binder is needed.
Dialysis Facilities and Patients
What do dialysis patients and providers need to know?
Like chlorine, chloramine can harm kidney dialysis patients during the dialysis process if it is not removed from water before entering the bloodstream. It is safe for dialysis patients to drink, cook with and bathe in chloraminated water because the digestive process neutralizes chloramine before it enters the bloodstream.
How do we prepare for the chloramine conversion?
The California Department of Health Services will inspect dialysis equipment and facilities to ensure providers successfully upgrade their dialysis equipment to remove chloramine before the conversion in Fall 2003. Dialysis units must be prepared for the anticipated chloramine concentration of 2 to 4 milligrams per liter. The maximum concentration allowed by law is 4 milligrams per liter.
Two methods are typically used to remove chloramine from water before dialysis:
• Ascorbic acid, or
• A granular-activated carbon filtration system specifically designed to remove chloramine.
Home dialysis patients should work with their home dialysis facility and physician to make necessary adjustments to their equipment.
Will boiling remove chloramine?
Chloramine cannot be removed by boiling water, adding salt, or letting water stand in an open container to dissipate the chloramine.
What will affected businesses need to do?
Certain businesses using highly processed water may need to remove chloramine from water prior to use. Restaurants or seafood suppliers with fish tanks, beverage manufacturers, labs and high tech operations are examples of businesses that should review current operations and take steps to ensure their water is treated appropriately for use.
Chloramine may require your company to adjust or upgrade its current filtration and treatment system. A water treatment professional or your equipment supplier can answer questions about how chloramine will impact your current system, and recommend solutions to fit your business needs.
How do I prepare for chloramine?
The SFPUC recommends reviewing your current chlorine removal approach to assess any needed changes to remove chloramine for the Fall 2003 conversion. A 2 milligram per liter chloramine level with a chlorine to ammonia-nitrogen ratio of 5 to 1 is expected. A residual disinfectant range of 2 to 4 milligrams per liter is forecast. Changes in pH, temperature, or turbidity are not anticipated. Companies requiring regulatory approval for their products should start early to obtain needed approvals.
What have other companies tried?
Companies report adding additional activated carbon canisters to their filtration systems or increasing chemical dosage to remove chloramine. Monitoring your system before and after conversion will ensure the treated water meets your requirements.
Chloramine cannot be removed by boiling water, adding salt or letting water stand
in an open container to dissipate the chloramine.
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