Water utilities in the USA are required to comply with the Enviromental Protection Agency's Lead and Copper Rule. This rule was passed in 1991 and sets the action level for lead in drinking water at 15 parts per billion (ppb). This means that utilities must ensure that water from the customer's tap does not exceed this level in at least 90% of the homes sampled. If the water from the tap does exceed the limit, then the utility must take steps to correct the problem.
On June 1, 2001, the Maui Department of Water Supply (DWS) began a corrosion control program by adding phosphates to the Upcountry water supply. The Hawaii State Department of Health Safe Drinking Water Branch mandated the use of phosphates to reduce the levels of lead that have been found in some homeowners' drinking water. Phosphates create a protective film on the inside of the pipe, slowing the electrochemical processes that lead to corrosion.On Monday, June 28, 2004, the Department of Water Supply (DWS) stopped the use of phosphates in the Upcountry water system. Phosphates were used since June 2001 to control lead leaching out of homeowners' plumbing.
To replace the phosphate, the DWS implemented a high pH, low alkalinity treatment, using soda ash. The DWS is required by the State Department of Health, Safe Drinking Water Branch, to implement and maintain an approved corrosion control program in order to minimize lead leaching. The pH of the water is approximately 8.8, not to exceed 9.4. The higher pH should make the water less corrosive. To comply with State requirements, the DWS is also monitoring nitrification throughout the system, collecting samples from customers' homes to monitor lead levels, measuring pH daily throughout the system, and increasing flushing throughout the system. Soda ash is the common name for sodium carbonate (Na2Co3). It is a sodium salt and is alkaline. It is commonly used in water treatment for pH adjustment and for corrosion and scale control. It is NSF/ANSI (National Sanitation Foundation/ American National Standards Institute) Standard 60 certified safe for drinking water treatment. Soda ash has been used for many years at the Piiholo Water Treatment Facility in Makawao. Soda ash works by producing an increase in the final sodium content, pH and alkalinity. The combination of higher pH and alkalinity can dramatically reduce lead solubility relative to lower pH and lower alkalinity water. The strategy is supported by scientific theory, laboratory data, and the practical experiences of hundreds of US utilities. For the June to September 2006 monitoring period, lead levels in the three water systems Upcountry were below the action level.| System | Lead | Copper | Makawao | 5.6 | <0.05 |
|---|---|---|
| Upper Kula | 5.0 | 0.33 |
| Lower Kula | 9.9 | 0.10 |
For comparison purposes, here are the Wailuku and Lahaina water systems results:
| System | Lead | Copper | Wailuku | <5 | 0.11 |
|---|---|---|
| Lahaina | <5 | 0.08 |
Where does the lead come from?
Lead is not detectable in the DWS system. It comes from lead-based solder, lead service lines, brass faucets, and bronze components. It is mainly found in older homes (pre-1986) where lead-based solder was used, or in homes in which high lead brass fixtures are used in plumbing systems.New fixtures can also leach lead. Regardless of the age of your home, you should get your water tested at the DWS Laboratory to find out for sure if your plumbing is leaching lead. The testing is free for Upcountry customers. Call 270-7550 for more information.
How does lead get into drinking water?
Upcountry water is surface water from the East Maui watershed (the native rain forest). This water has a low alkalinity and a low pH, due to plant materials found in the source water. Also, this water is "soft water" which does not provide a natural protective coating of calcium carbonate in the pipes. These factors plus lead solder or brass fittings in plumbing can cause lead leaching into homeowners' drinking water.
How do I know if my house is at risk?
Your household may be at risk of lead contamination if:
- Your water main or pipes are made with lead
- Your home has copper pipes with lead solder
- Your home was built before 1986
- You have brass fixtures
- Water sits in your home's pipes for several hours or longer.
What should I do?
- Call DWS at 270-7550 to get your water tested for lead (leave a message with your name, address, and phone number).
- Find out whether your pipes and fittings contain lead or lead solder.
- Run your water for 15 to 30 seconds or until it becomes cold before using it for drinking or cooking. This flushes any dissolved lead from the pipes (use that water for your plants).
- Don't cook with or drink water from the hot water tap; lead dissolves more easily into hot water.
- Do not boil your water to remove lead. Excessive boiling water makes the lead more concentrated - the lead remains when the water evaporates.
- Check out the EPA's fact sheet on lead for more steps you can take.
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When did the DWS stop using phosphates?
We stopped using zinc orthophosphate (C-9) on April 10, 2003. Phosphoric acid was used from April 10, 2003 to June 28, 2004.
What else is the DWS doing?
We are currently working on an EPA grant. The purpose and goal of the grant is to test homes in upcountry Maui and remove the source or sources of lead contamination. This project will identify ways to minimize exposure to lead in water for persons living in Upcountry Maui; will identify if there are elevated lead levels in children and women of child-bearing age; will address community's concerns about possible secondary impacts of corrosion control practices; and will provide education and communication to the public on lead exposure and risks.The prime purpose of the grant is to determine the source or sources of the lead contamination. Voluntary lead testing for children in the upcountry region, and public education on the dangers of lead contamination are also primary purposes of the grant. By knowing these reasons DWS can move toward reducing the lead leaching into the Upcountry Maui water to stay below the USEPA action levels of 15 ppb (parts per billion) in 10% of the homes tested. Voluntary lead testing for children will be under the guidance of Maui DOH (phone number 984-8200). For more information or to participate in the grant work group, please call Deputy Director Jeff Pearson at 270-7834.
As part of the grant,the DWS is also be working with a consultant to see how the water system Upcountry can be improved. They will be taking samples, looking at the water source, the transmission and storage facilities and treatment techniques to see how we can improve the water we provide.
In 2004, the DWS hired consultant Dr. Marc Edwards of Virginia Tech to see what could be causing the lead problems. To learn more, read the report in PDF format, Evaluation of Lead Corrosion Control Strategies in Maui Water.
DWS staff flushes dead ends of the Upcountry water system to draw treated water into low-use areas. Other parts of the the water system are flushed monthly.
The Maui DWS Laboratory will continue to monitor lead levels by taking samples throughout the Upcountry system.
The Maui County Council adopted Resolution No. 03-39, urging the Maui DWS to work with the community to remove lead plumbing from customers' homes. Click here to read the Resolution in PDF format.
Are other areas of Maui County affected by corrosion?
No. Water for the Central Maui, Hana, and Molokai systems is groundwater, which has a higher alkalinity and is "hard water." Hard water provides a protective eggshell-like coating in the pipes and corrosion does not occur. The Lahaina system is supplied by surface water, but is supplemented by groundwater which protects the system from corrosion.
Who can I call if I have questions about the quality of my drinking water?
If you have questions about your water quality or want to have your water tested, call the Maui Department of Water Supply laboratory at (808) 270-7550 (leave a message with your name, address, and phone number). If you have health concerns, please call the State Department of Health toll free number 984-2400, extension 64258.
Please view the Water Quality Report for Upcountry for more information and details on the area's water system.