Safe drinking

Efforts are increasing to purge lead from residential water systems, writes Shukri Elmazi
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Since 1991, the United States Geological Survey has been monitoring water quality, compiling a data warehouse of how natural processes and human activities affect water-quality conditions.

With a reported 44 million people in the US relying on private wells for their drinking water, the quality of source water and drinking water associated with domestic wells is a serious subject. The health risks associated with harmful substances, such as lead contaminating or leaching into residential water systems, has sparked national concern and prompted legislative changes to the Safe Drinking Water Act.

Many residential water systems operate using older plumbing fixtures and copper water lines that may contain lead in the solder used to bond the pipes, which can pass lead into a home's potable water supply. Though the use of lead-containing solder has been banned since the enactment of the Safe Drinking Water Act of 1986, plumbing that was installed before that time might contain lead. That's why it's important to ensure that homeowners know most residential water-treatment systems are comprised of replaceable components that require regular service and maintenance.

As part of its proposed changes to the Safe Drinking Water Act, the United States Environmental Protection Agency (EPA) seeks to ensure individuals purchasing, installing or inspecting potable water systems can identify lead-free plumbing materials.

Mandating manufacturers to certify compliance with lead-free regulations ensures products that meet them are differentiated from those that are exempt. The EPA's proposed regulations would also reduce unintentional use of non-lead-free plumbing products in potable water systems and minimise exposure to lead in drinking water. 

The EPA seeks to update the definition of lead-free in Section 1417 of the Safe Drinking Water Act based on the Reduction of Lead in Drinking Water Act of 2011. The proposal calls for lowering the maximum amount of lead content allowed in plumbing products from 8% to 0.25% of the wetted surfaces and create exemptions from these requirements for plumbing products that are used exclusively for non-potable services.

Some manufacturers, including Xylem's Goulds Water Technology, have retooled the manufacturing process of their residential pump products to meet stringent lead requirements well before the EPA's proposed regulations were announced. In fact, some Goulds Water Technology products have been engineered with stainless steel since 1994 to ensure they contain less than 0.05% lead.

As other companies work to update their product lines to adhere to the proposed guidelines in Section 1417 of the Safe Drinking Water Act, plumbing professionals can help homeowners assess if they are at risk for lead exposure.

Inspect for lead

Plumbing professionals should thoroughly examine a home's water system to find potential sources of lead. Start by identifying the materials used to construct the pumps that move water into and throughout the home to ensure they do not contain lead. Then, characterise the material used to connect the pumps to the piping. When doing so, look for solder joints. Prior to 1986, solder was commonly used to connect copper piping in older homes and contains lead. Then inspect the fixtures that are installed in the home. Household fixtures in bathrooms and kitchens might be made of brass or bronze. These materials also contain lead.

When lead gets into tap water, it typically happens right before the water enters the home through a service line. Service lines installed before 1986 commonly contained lead-based solder constructed of 50% tin and 50% lead. For this reason, it's critical to identify if the pipe providing water to a residential system is made of plastic, copper, lead or stainless steel. This will help plumbing professionals understand if high volumes of lead are seeping into the water before it enters the home's service line.

To do so, find the water meter located inside or outside of a resident's home. Then evaluate the material used to construct it. If the pipe is made of plastic, that means it's likely safe. If it is made of metal, use a key or coin to scratch it and then evaluate the colour of the pipe. If the pipe is orange, it likely was made of copper, which usually indicates a lower lead concentration. If the scratched surface is a dull colour, it's likely made of galvanised steel, which can also contain lead. If the surface is shiny, lead is most likely the main material used to construct the pump.

Even if a home does not use a lead service line or contain pumps made with lead, residents can still have unsafe levels of lead in their water supply due to leaching from the faucet, pipes and other fixtures, especially if they live in a region with potentially corrosive groundwater. The only way to ensure homeowners' water doesn't contain harmful quantities of lead is to test it.

When testing the water, measure the lead content to ensure it meets EPA regulations. Water professionals should test more than one water sample. This is because varying amounts of lead may be in different water supplies. Test water samples that come from all major water sources in the home. This should include but not be limited to the first draw in the morning and from water streaming from the kitchen and bathroom sinks and shower.

Upgrade systems as needed

If all or parts of the residential water system contain unsafe quantities of lead, upgrade as needed with lead-free pumping products. To further ensure contaminants don't make their way into a home's potable water source, install products that are NSF/ANSI 61-G or NSF/ANSI 372 compliant. This means the product has been tested and evaluated by a third-party testing body to ensure it does not leach contaminants into the water that would be a health concern, and it complies with safe potable water regulations.

Replacing lead service lines and pumping infrastructure removes lead from the source, but it can be expensive. For this reason, many homeowners elect to have water treatment devices, such as filters, distillers and reverse-osmosis units, installed in their homes. It's critical that plumbing and water-treatment professionals install water-treatment systems that are NSF/ANSI 53- or NSF/ANSI 58-certified. This ensures the system has been verified to be able to reduce lead to below the EPA action level of 0.015mg/L. 

Ensuring the safety of drinking water in both municipal systems and private wells is an ongoing process, one that involves government, manufacturers, industry professionals and homeowners working together to ensure the health and safety of all.


Shukri Elmazi is a product manager for Xylem. Elmazi has worked in Xylem's Applied Water Systems Unit for 10 years and has extensive experience in residential product development and systems training

 

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