How much lead is OK?
No lead is good lead, but some lead is realistic.
I woke up recently to the announcement that the State of Illinois is mandating that every school’s water must be tested for lead. This is new legislation that just passed.
The big media blitz regarding lead in drinking water originates from horror stories of the Flint, Mich., drinking water crisis. Following that incident, a few schools in Chicago tested their water. The schools claimed that there were a number of failures, so apparently they went to the state.
Notice, in all of this, that I didn’t mention any numbers. Nor did any of the reports. It was just “bad” or “failed” or “damaging to our children.” This is the problem with a lack of understanding of lead in drinking water. You need more than hysteria to determine if there is a major lead problem.
A number of years ago, I wrote an article entitled “No Lead is Good Lead” (PM, January 2008). I will stand by those statements. We need to do everything possible to eliminate lead from our drinking water. That doesn’t mean it is easy or cheap.
Unfortunately, like any crisis, there are the ambulance chasers that want to tell you the sky is falling. Then you need to spend billions of dollars to keep the sky from falling.
I wish I could write that we have completely solved the problem of lead in our drinking water. I wish I could write that all of the lead contamination has been removed. However, that just isn’t true. There are many water systems in the U.S. that have lead in the drinking water. The question you should be asking is: “How much lead?”
The U.S. Environmental Protection Agency has a goal number of 0% for lead concentration, or no lead. While that is the goal, the lead action level for drinking water is 15 parts per billion (ppb). We are dealing in billions, not millions. With the world population being 7.5 billion people, imagine having only 113 people on the entire planet made of lead. That is what 15 ppb equates to.
When EPA first started regulating lead, the action level was 50 ppb. That value was lowered to the current 15 ppb. NSF 61, which regulates plumbing products, currently uses a value of 5 ppb.
The EPA and NSF values have different meanings. The lower NSF value is used to determine the quality of material used in plumbing systems. Specifically, brass or bronze is tested using special test water to determine if the material is leaching lead. A copper alloy faucet, valve, or fitting cannot contribute more than 5 ppb of lead to the drinking water.
The EPA action level number is used to regulate the water supply provided by the water purveyor or water utility. Samples are required to be taken from faucets in homes and analyzed. The number of homes required for sampling is dependent on the size of the utility.
The concentration of lead in the samples is listed in ascending order. The concentration of the 90th percentile sample determines if the water purveyor must take action. If the concentration of lead at the 90th percentile exceeds 15 ppb, something must be done. Typically, corrosion inhibitors are added to the drinking water at the water treatment plant. The common corrosion inhibitor used in drinking water is orthophosphate, which is used to reduce the corrosion in lead, brass, and copper.
If you read between the lines, this means 10 percent of the samples taken can have lead levels above 15 ppb. This is considered acceptable by EPA, even though the lead concentration in those water samples exceeds the action level.
When doing individual testing of a water sample, a concentration of lead above 15 ppb does not mean that the water failed the lead test. What it means is that the particular sample was above the action level. There is a distinct difference. Hence, when you read a report that just says a test failed for lead, you need to know how many samples were taken and what the percentage of samples is above the action level.
Let me repeat: No lead is good lead. However, if a water sample does not hit the EPA action level, it does not mean that the lead is immediately contaminating the individual drinking the water.
First, realize that the samples taken for testing are first draws. In other words, the faucet isn’t used for the previous 12 hours and then it is opened to take the water sample. Additional water is flushed, and a second sample is taken.
The beauty of our water supply is that once the lead is flushed out, the remaining water typically has a much lower concentration of lead when compared to the sample being tested. Hence, for a school, the same pupil would always have to drink the first draw every day for it to be a problem. With so many students, the first draw is typically a different pupil each day, if they even manage to capture the first draw when drinking the water.
If there is a perceived problem, the blood lead levels of the individuals drinking the water can be tested. If there ever is a major concern, blood testing should be conducted. Lead is measured in micrograms per deciliter of blood. While no level of lead is good, the medical profession has blood levels that indicate problems. I mention this because, before millions or billions are spent on new plumbing systems, there should be a determination as to whether the lead is contaminating the people that are drinking the water.
While the goal should always be the reduction of exposure to lead, that doesn’t mean that every plumbing system must be replaced or re-piped if a water sample has a lead concentration above 15 ppb. Sometimes the lead is coming from the public utility. The renovation of a building’s plumbing system won’t help the lead coming from the water purveyor.
Any high readings should simply be an indicator to evaluate the source and try to reduce the exposure. Sometimes it may be as easy as having the janitor open all of the drinking fountains for a minute first thing in the morning. At worst, it may require the replacement of all of the drinking fountains and part of the plumbing system.
Be smart; don’t be drastic. We have been battling lead in drinking water for the last 40 years. We knew back then that we would not solve lead in drinking water overnight. We still won’t solve the issue overnight.