Coal Ash, Parts Per Billion, and Risk

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Coal ash ponds at Possum Point before Dominion Virginia Power started draining the ponds and consolidating the coal ash.

Kudos to Robert Zullo with the Richmond Times-Dispatch for digging beneath the dueling press releases to shed light on the contamination risks that coal ash ponds pose to drinking water. Focusing on the carcinogenic chemical hexavalent chromium, which has been detected in well water near Dominion Virginia Power’s Possum Point Power Station, he broaches key questions: How much of the chemical is too much? What level should the state permit?

Other questions he touched upon in passing: If hexavalent chromium exists in well water, how did it get there? Did it come from the coal ash ponds, or does it occur naturally in minute quantities?

The Environmental Protection Agency (EPA) sets a drinking-water standard of 100 parts per billion for chromium, which Virginia’s Department of Environmental Quality (DEQ) has adopted as its own standard. However, hexavalent chromium is widely regarded as a more dangerous version of the metal. California has set a separate limit of 10 parts per billion for drinking water for that compound, Zullo reports, reflecting a balance between health risks and the cost to water utilities of meeting the level.

Dealing with its own coal ash problem, the state of North Carolina conducted tests last year of well water within 1,500 feet of coal ash basins, using a standard of 0.07 parts per billion, which it determined was associated with a “potential one-in-a-million cancer risk for an average person drinking this water over an average lifetime.” Tarheel regulators issued several hundred “do not drink” letters to private well owners last year. Critics contended that the 0.07 parts-per-billion level was so strict that even municipal water systems could not meet it, and the state reversed course, telling residents that their well water was “just as safe as the majority of public water supplies in the country.”

The issue surfaced in Virginia when DEQ tested seven private wells near Possum Point and found hexavalent chromium in one — 5 parts per billion, right at the state’s reporting limit. The Southern Environmental Law Center (SELC) commissioned other tests and found another house where the chemical was found at a 1.2 parts-per-billion level.

SELC argues that DEQ should use testing methods that identify the chemical at levels lower than its 5 parts-per-billion standard. Said Greg Buppert, an SELC attorney: “This is a human carcinogen and we should be looking at it at lower concentrations, because we know it’s a concern.”

Bacon’s bottom line: What we’re talking about here is measuring minutes quantities of hexavalent chromium and parsing minute risks. From my (admittedly primitive) understanding, there is no known level above which a given chemical in the drinking water is dangerous and below which it is “safe.” We’re dealing with a continuum in which the statistical risk diminishes with smaller concentrations of the chemical. North Carolina’s level of 0.07 poses a risk of one-in-a-million people getting cancer after a lifetime of drinking the water. That’s crazily low. Even if hundreds of households drank the well water for years, the odds are remote that a single person would get cancer from the chemical.

One must balance that against the cost of eliminating that risk, which in Dominion’s service territory could approach $3 billion. If Virginia rate payers kept that money, what would they do with the money? Presumably, they would spend it on other things. Sure, they might buy a bigger house or purchase more movie tickets. But they also might purchase safer cars, have more frequent medical check-ups, eat healthier food, or join a health club. When we take money from people, whether through taxes or regulation, we fail to take into account the fact that we deprive them of the means to mitigate every-day risks to their health and safety.

Life is full of risks but we as a society say we can live with them. The Virginian-Pilot reports today on a fluke accident in which a beach umbrella on Virginia Beach was blown loose from its moorings in the sand and struck a woman, killing her. Should we ban beach umbrellas to offset the risk of umbrella impalements?

On the other hand, Virginia’s legal limit for hexavalent chromium is more than 100 times North Carolina’s one-in-a-million level. Assuming a straight-line correlation between the hexavalent chromium level and the risk it poses, that implies a one-in-ten-thousand risk or greater for Virginians drinking contaminated well water. That sounds like enough risk to justify having a conversation.

Then there’s a subsidiary question: Do the traces of hexavalent chromium in well water come from the coal ash ponds or do they occur naturally in the environment? That’s not clear yet. DEQ’s consultant found that “natural hydrological processes do not allow for movement of shallow groundwater from the Possum Point Power Station towards the residences on Possum Point Road.” Is that, in fact, true? What are those hydrological processes? Can this statement be verified with reasonable certainty? If the consultant is correct, spending billions to truck the coal ash to landfills would accomplish nothing. If he’s wrong, then Dominion should take responsibility for the contamination.

These are the kinds of questions we should be asking. In “Once in Four Lifetimes,” I tried answering similar questions surrounding the discharge of coal ash wastewater into rivers and streams. Zullo has done a commendable job exploring the groundwater contamination issue. Let’s hope we see more reporting like this.

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4 responses to “Coal Ash, Parts Per Billion, and Risk

  1. The movie Erin Brockovitch was about hexavalent chromium from utility operations, although I don’t know the concentrations involved with that case.

    Health effects are not necessarily linear with concentration, sometimes they have a logarithmic relationship. Also hexavalent chromium is also not the only contaminant in the well water. Many other heavy metals and other toxic compounds exist in the runoff water. Just as we know so little about multiple drug interactions, we don’t know that much about the effects of multiple toxic chemicals. Especially if they exist in concentrations below what we consider “dangerous” for a single chemical.

    It is better for us to find ways not to create these wastes in the first place. I don’t have the details or the reference, but I recently saw a summary of a study that said the health effects of U.S. coal plant operation cost about $500 billion per year! Spending the same amount annually on energy efficiency and other non-polluting alternatives would seem to be a more sensible social investment.

  2. so – the cost of making sure a private well is not contaminated is the cost of the owner or the state and the state is quoted as saying: ” “We don’t have a budget to perform these tests,”

    So Dominion is not responsible and the State refuses to really do due diligence and what we know about these things in general is that:

    1. – the company maintains there is no threat or harm
    2. -the govt often does what Virginia is doing – little or nothing unless someone pays out of their own pocket or an agency like Va Tech looks into it – and then when it blows up -the state finds that money.

    3. the typical history on these issues is that the govt often underestimates the threat – or dismisses it then further analysis and research shows that it is much more harmful than originally thought.

    4. – the statistic measure of how many folks will get cancer in how many hundred thousands – also often turns out to be a WAG… that the State and the Company are just fine with until someone else finds out different.

    Basically neither Dominion nor the State has much interest in doing a thorough and convincing analysis that passes muster for most.

    More typically it turns into a heel-dragging, prove-it-if-you-can , contest.

    Not arguing for pristine here and totally acknowledging that anything in life has risks and that we cannot remove them all or even afford to remove a lot of them…

    At the same time, I have little confidence and an abundant history of past practices and behaviors to expect more and better from Dominion and the State.

    these things often have a predictable process and outcome and I’m not going to be surprised if this ends up gaining momentum and Dominion and the State finding themselves back-peddling…

  3. Public resources are not infinite. We make choices in this world, and one of them is to allocate health care and exposure to health risk. It is totally wrongheaded to try to reduce just one such risk to zero at the cost of ignoring many, indeed most, others. That would be the opposite of ‘the greatest good for the greatest number.’

    • I totally agree – but in order to make those choice – you need to be informed and that’s my problem with the company and the state as neither of them is promoting clear and unambiguous information from which to make a truly informed choice. Instead, both are happy with “vague” are asserting THEIR viewpoints

      FOR INSTANCE – there is a fair amount of peer-reviewed studies available – what do they say? do we have a literature review provided?

      How do other states, and Europe or Australia or Canada consider it regulatorily and treat it physically?

      The litigant – the Southern Environmental Law Center HAS done some of that analysis – has concerns and are not exactly a wild-eyed “enviro greenie” group.

      I DO expect – at the end of the process after the data and pros/cons are out there for the public to see – for Dominion and DEQ to make their calls.

      but at this point – what we have is a rugby scrum of a process and while Dominion and DEQ be okay with it – ultimately it undermines the public’s confidence in either one of them as reliable and trustworthy agents.

      Finally – all the back and forth on the cost and subsidies for solar – compared to “cheaper” fuels – and what do we get when we deal with impacts and the costs of those impacts – and the reality that those costs are also “subsidies”

      how do you calculate the best and available use – the value , the taxable value of property – permanently taken out of production and turned into a forever waste dump that 10, 20 , 50 years later they find out that – in fact, it’s not “inert” and has to be excavated and properly disposed of – at taxpayer expense?

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