Why I Think California’s Proposed Hexavalent Chromium Drinking Water MCL May Do More Harm Than Good.

Due to intense political pressure brought about by various interests and a huge case of media fueled confusion, California is on the brink of implementing a hexavalent chromium (chrome 6) drinking water maximum contaminant level (MCL) of 10 ug/L.  This is 5 times lower than the current total chromium MCL in California of 50 ug/L, which is itself half of the Federal MCL of 100 ug/L for total chromium.  There is no Federal hexavalent chromium MCL.  The MCL was based on the California Public Health Goal. Using ambiguous and arguable science, the California Office of Environmental Health Hazard Assessment (OEHHA) set a PHG of 0.02 ug/L.  “The PHG for chromium 6 is 0.02 parts per billion (ppb), which is the estimated “one in one million” lifetime cancer risk level. This means that for every million people who drink two liters of water with that level of chromium 6 daily for 70 years, no more than one person would be expected to develop cancer from exposure to chromium 6. The “one-in-one million” risk level is widely accepted by doctors and scientists as the “negligible risk” standard.” (From the OEHHA chrome 6 PHG fact sheet.) 

The California Department of Public Health (CDPH) currently sets MCLs in California, although that’s about to change; see California Drinking Water Reorganization Transition Plan on the WeWork4Water Blog.  “MCLs take into account not only chemicals health risks but also factors such as their detectability and treatability, as well as costs of treatment.  (California) Health & Safety Code §116365(a) requires CDPH to establish a contaminant's MCL at a level as close to its PHG as is technologically and economically feasible, placing primary emphasis on the protection of public health.” (From the CDPH MCLs and PHGs web page.)  There are two places in this statement where the process for chrome 6 got problematic: CDPH has underestimated the incidence of occurrence and thus the cost of treatment; and in that last phrase, placing primary emphasis on the protection of public health.  If the emphasis is on doing the most good for public health, then the proposed MCL will be a disservice to the residents of California. Why?  Because the cost/benefit analysis just doesn’t pencil out, and the excessive costs will negatively impact the health of the general public, particularly those at lower socio-economic levels.

CDPH is required to take into account the cost of treatment when they propose a new MCL.  That analysis requires two basic pieces of information: One, how often does chrome 6 occur and at what levels; and two, how much does it cost to treat those sources that are at or near the MCL. The analysis that CDPH conducted significantly underestimated the occurrence of chrome 6, and thus the number of sources that will require treatment at the proposed MCL.  It also underestimated the cost of treatment for those sources that require it.  Both of these parameters, fortunately, have been reviewed independently by researchers who are leaders in the field.  Technical Review of the Occurrence Analysis Supporting the DraftHexavalent Chromium MCL by California Department of Public Health from the Jacobs Group, Dr. Christopher Corwin and Dr. Chad Seidel reviews occurrence data.  According to this analysis, the number of sources that will require treatment is 437% higher than estimated by CDPH at 1,360 sources.  Small systems serving less than 200 service connections, which are least likely to be able to pay for treatment, account for 71% of the systems impacted, with 46% of the sources.  Review of CDPH’s Economic Analysis Supporting the Draft California MCLfor Hexavalent Chromium in Drinking Water by Dr. Issam Najm reviews the costs associated with treatment.  Dr. Najm calculates that the total cost of treatment will go as high as $4.1 billion dollars, or nearly 5 times what CDPH estimated at $871 million.  And remember, the bulk of the $4.1 billion will be borne on the backs of water systems serving less than 200 connections, very few if any of whom will be able to pay for it.

The incredible costs associated with treating for this compound will result in several significant issues.  One result will be a situation similar to what California already faces in regard to compliance with the nitrate and arsenic MCLs, where many small systems continue to serve their customers water that does not meet one or the other of these standards because the water system can’t afford the cost of treatment.  Many of these small systems serve communities that are seriously economically disadvantaged, so raising rates to pay for new treatment is not an option; their customers simply would not be able to pay.  In this case, you will end up with some people who continue to drink the water from their tap, because it’s all they have.  Others will spend whatever limited funds are available to buy bottled water for drinking and cooking, thus decreasing the discretionary funds they may have had and negatively impacting their economic status even further.

In water systems that are a bit larger, with a mix of customers in different socio-economic strata, there may be more resources to deal with the situation.  These systems will likely install treatment, resulting in very large increases in rates.  Examples of California water systems in such a situation are those in Watsonville, which estimates that rates will increaseby 78% to cover the costs of treatment; and the Coachella Valley Water District, which estimates bills will go up by $50 per month.  Those kinds of rate increases will also significantly impact the discretionary funds available for many consumers.

Do a Google search, or use whatever your search engine of choice is, and look up “socioeconomic status and health care”, and you’ll get back more results than you can possibly read all saying the same thing: the lower a person’s socioeconomic status, the lower their general health and life expectancy. I don’t think that will be a surprise to anyone.  The less income you have, the less access you have to healthcare, the less likely you’ll be to have access to healthy eating choices, and the more likely you are to develop a whole list of serious health issues.  The amount of money people in already compromised circumstances will have to pay for higher water bills or to buy bottled water if this chrome 6 MCL is implemented will reduce the amount of money they have for healthcare and good food, thus reducing their overall health more than could ever possibly be made up for by reducing the level of chrome 6 in their drinking water.  It will be a net loss in terms of overall health protection for a very large segment of the population.

As a water quality professional, I think everyone is entitled to clean, safe drinking water. Where the problem lies is in defining what that means. It doesn’t mean water that has absolutely nothing else in it but H2O molecules. That would be impossible, and probably cause its own adverse health effects. So the issue is in finding a balance. Just because we can measure something analytically doesn’t mean it should be regulated. The diminishing returns between what little health benefit such a regulation might bring needs to be carefully weighed against the harm it might cause through other impacts to people’s lives. California’s proposed chrome 6 regulation is just such a situation where the negative impacts to the state’s population will outweigh any benefits.

Thanks for reading, and don't forget to leave a comment.  Or feel free to send me one at patrick.vowell@wework4water.com