Presenting SimpleWater’s new 'Lead Map', designed to help you assess the risk of lead and other heavy metals in your drinking water
Is There Lead Where You Live?
This map will be most relevant to people living in smaller towns with small water systems that get their water from the ground. Although many small water systems are run well, it's often the case that they lack resources to monitor and update infrastructure in a timely fashion or manage the water's chemistry carefully. In theory, larger city water systems adjust their water's chemistry continuously to prevent health risks, but, as we've learned from Flint, this is not always the case.
Explained: The Lead Map (Version 1)
Whether you are exposed to lead and other heavy metals from pipes in your drinking water depends on several factors. Two very important ones are the age of your neighborhood’s infrastructure and the corrosiveness of your water.
Old pipes are known to contain harmful metals, which corrosive water can dissolve and travel to your tap. Over time, small concentrations of these often invisible, flavorless metals–including lead, arsenic, copper, aluminum, cadmium, chromium and zinc–can accumulate in your body and brain and cause very serious harm to your health. Young children are the most vulnerable to lifelong problems from these effects.
In response to health concerns related to pipe corrosion and aging US infrastructure, SimpleWater is developing detailed water quality maps for every community nationwide. Our goal is to give you a more personal sense for your water’s potential health risks, and to arm you with fast and effective remedies.
The Lead Map: How We Made It
SimpleWater’s Lead Map (Version 1) uses the average age of homes in your county as well as the average corrosiveness of your state's groundwater to predict the likelihood for dangerous levels of lead (and other heavy metal) exposure in your neighborhood’s water.
The Version 1 Lead Map combines two key indicators for lead exposure risk:
- The corrosive potential of groundwater, by state.
- The average age of homes in every county.
This project is at an early stage. We expect to continue making improvements to this map in the near future. For a specific look at your personal health risks from lead and other heavy metals in your water, we encourage you to analyze it with a Tap Score Home Testing Package.
What is Corrosive Potential?
Corrosion refers to the chemical interaction between your water and the metal surfaces it touches. There are two extremes to corrosiveness which we care about:
- Water with low pH and Low Alkalinity will dissolve metals into your water and weaken your pipes over time. Alkalinity is a measure of your water’s ability to maintain a stable pH.
- Water with high pH and high Alkalinity will add material to the inside of your pipes and cause scaling that can lead to clogging and other issues.
In a perfect world, your water is in healthy balance with all the piping that it touches -- metals are not being dissolved from the pipes, and ionic material is not getting added to the pipes as scale.
Corrosion matters to you for several reasons:
- Corroding pipes can contribute harmful metals to your water quality, like lead copper, chromium and zinc.
- Corroding pipes can cause your plumbing systems to fail in your house.
- Corroding pipes can cause bitter tasting / bad looking water (although you may not notice).
The Corrosive groundwater data used in the SimpleWater Lead Map comes from information provided by the USGS:
The average age of homes in your county is used as a proxy for the average age of the pipes which serve drinking water to you and your neighbors. This is not a perfect system because water pipes may be older or newer than homes, but as many towns and cities have poor records on the real age and material of drinking water pipes, it is the best approximation we can make at a national scale.
SimpleWater uses an index of 1 - 4 to rank a county's average home age. The oldest (and most vulnerable) counties score high with values of 3 and 4. Counties with newer homes that were likely built during eras of tighter lead regulation score lower values of 1 and 2. Home age data is sourced from the 2015 US Census.
- When the average age of homes is older than 1960 (when lead in pipes started getting phased out slowly) = 4
- Older than 1973 (half the distance to 1986) = 3
- Older than 1986 (lead pipes outlawed completely) = 2
- Newer than 1986 = 1
Corrosive Potential and Age Combined
We add both indexes (corrosive potential and house age) to give a total score for every location on the US map. Every score falls between 2 - 8. We have separated these scores into 4 color groups, as 8 colors would be difficult to distinguish on many screens.
Evaluating Your Personal Risk
This map relies on large-scale, nationwide data to paint an overall picture of where lead and other heavy metals might be more likely to pop up in groundwater-sourced drinking water. As an individual, the best thing you can do is to test your own water, but you can also get more from this map by figuring out when your neighborhood was constructed and whether your local water system has been diligent in upgrading distribution pipes.
If your water comes from a private or shared well, it's up to you to make sure the chemistry of the water is balanced, and that the pipes taking that water into your home are maintained.
Any Questions? Contact us at firstname.lastname@example.org
Liked this map? Check out The Coal Ash Map.