Articles, Blog

Radionuclides in Private Wells of Wake County, NC

February 8, 2020


good morning I’d like to welcome
everyone to the fourth in our series of eight webinars for national radon action
month my name is Sara Kirby I’m at NC State University and I work with NC
State Extension. I’m also a housing specialist here and our job today is
really to be the technical host of this webinar series. This has been a wonderful
I think opportunity to learn more about radon all aspects from health to
location to research that’s going on in this area but I want to turn the
presentation over to Phillip Gibson who is a radon specialist with the NC Radon Program here in North Carolina and so I’ll turn it over to you and he’s the
brainchild behind all of this so Phillip take it away. thank you Dr.
Kirby before I go into introductions I want to note to everyone that in the
chat box and I think Sarah correct me if I’m wrong in the chat box
are where you can find or is where you can find the documents that I’ve
uploaded that are connected to this presentation and to radon in general
specifically you may want to look at the radionuclides radiological fact sheet
and then the final report of the North Carolina radon in well water report that
came out of a number of years ago but also Dr. Kirby I wanna thank you once
again for making this webinar possible by sharing your time your expertise and
the technology of North Carolina State University to everyone who’s joining
thank you for your participation this session is being recorded and like the
others will have closed captioning added to it and then made available and I will
email you a link to access that but later they will be on our website at ncradon.org. I also want to acknowledge the support that we’ve had
in reaching various audiences for this and the webinars that have been
conducted the organizations that partnered with us to market these events
are represented in this slide that Dr. Kirby is sharing so our speaker today
which I’m really excited I’ve I’ve heard Evans speak on a number of occasions and
I’m learning something every time I hear him present our speaker today is Evan
Kane Evan manages the groundwater management section of the Department of
Environmental Services for Wake County in North Carolina he oversees Wake
County’s programs for permitting and inspection of private drinking wells for
drunk drinking water wells and programs for outreach testing and technical
assistance for private well users and prior to joining Wake County’s
Department of Environmental Services Evan worked for the North Carolina
Division of Water Quality for 14 years developing and implementing programs for
groundwater protection and groundwater monitoring he has also worked for the
North Carolina Geological Survey mapping the geology of the western coastal plain
and eastern Piedmont of North Carolina he has also worked for a private
environmental consulting firm assessing groundwater contamination and
manufacturing sites and evan has his degrees his bachelor’s in this master’s
degree as a North Carolina licensed geologists in geology from North
Carolina State University so I would like you to join me in welcoming Evan
Kane okay everything good is great okay great
so I’ve entitled this talk radionuclides in private Wells I probably
should have subtitled it one County’s experience Wake County Department of
Environmental Services is a component of the local health department for Wake
County North Carolina and we have a some interesting programs going on related to
private drinking water wells so we want to share our experience here with
radionuclides in private wells this really builds on several years of
studies and work by others in North Carolina but also other states
experiences with this issue and really informed our approach to this just a
little bit of background about Wake County North Carolina we are you just
for a second I don’t believe your screen is sharing okay okay that better perfect
thank you okay so just a bit of background for those not familiar with
it Wake County North Carolina is the
capital County sorry coast to the capital of North Carolina okay the total population of the county
is just over 1 million we’re rapidly growing adding about 56 new residents
per day you’ve probably heard of the Research Triangle Park and would think
of this part of North Carolina as being very modern
and we are in many respects but we also have a fairly high reliance on private
drinking water wells public water supplies either run by municipalities or
investor owned utilities serve about 85 percent of the residents of Wake County
the remaining 15% are served by private drinking water wells so these are wells
that are not covered by the Safe Drinking Water Act there is no
requirement for a qualified operator and responsible charge within North Carolina
we actually have a pretty proactive private drinking water well program that
requires permitting and inspections of private drinking water wells when they
are installed and requires a certain amount of testing at the time that
they’re installed but after those initial approvals the well owner is
responsible for the ongoing maintenance and testing of the water supply which
you can imagine creates some challenges because it’s John Q homeowner who is
running that water supply and may not always understand what risks are out
there in that drinking water the hundred and fifty thousand residents are served
who rely on private wells are served by about forty thousand wells countywide
many of which predate our permitting program and we are still installing
about 400 new wells annually in Wake County to serve new development
replacement wells etc so in order to help those well owners with their
responsibilities for maintaining their water supplies we’ve been running a
pretty active Technical Assistance Program for several years just we offer
a pretty comprehensive well water testing services through our own
in-house lab as well as a contract laboratory and we’ve been trying to help
people anticipate what their problems might be and get the proper testing for
those things as we begin reviewing several years
worth of data collected from our technical assistance program we were a
little bit surprised by the results this chart just represents the percent of
samples that we’ve pulled that exceeded EPA drinking water standards in an
initial test from a private well and some of the usual suspects like nitrate
and fluoride you can see here we have just one or two percent of the samples
exceed the drinking water standards for those also man-made chemicals like
pesticide dieldrin or chlorinated solvents Reichl or ethylene exceed
drinking water standards and a very small number of wells obviously it’s a
concern for those individual cases but what we found was that uranium and it’s
essentially a proxy of uranium grouse alpha activity standards are exceeded in
10 to 20 percent of the samples that we pulled over roughly a 5 year period that
makes these the most common contaminants of health concern to exceed drinking
water standards in the county and actually fits with a national trend
there was a paper from the USGS DeSimone and others back in 2009 that looked at
about two decades worth of testing of domestic wells nationwide and found that
naturally occurring contaminants were the most common ones to occur above
health-based standards in wells nationally so in our case it happens to
be uranium and some other radionuclides but if you go to other counties with
different geology you would see maybe arsenic is the most common issue so kind
of fitting with a national pattern we had some reason to suspect that these
were naturally occurring issues but just to be sure we did overlay our well
testing data on detailed geologic map of the
detailed mapping was fairly recently done by the North Carolina Geological
Survey and we’re able to determine that a particular geologic formation and some
nearby rocks that have been impacted by that formation contain most of the
exceedences that formation in particular is the Rolesville granite it is a
Pennsylvanian aged granite which also has a lot of intrusions of granite into
the surrounding rocks and seems like the logical culprit here so initially we did
a study on uranium occurrence in wells over about a five year period and as we
began learning more and more about the uranium issue in well water one of the
first things that became clear was that this is not limited to uranium but
uranium is just the start of the decay chain and so there will be multiple
radionuclides present in the groundwater in an area where the rock is naturally
enriched in uranium primarily from a drinking water perspective and human
health perspective from well water we are looking at three main elements
uranium radon and two isotopes of radium health risks I think are pretty well
known to people but just to recap with uranium the drinking water standard is
actually set based on uranium’s behavior as a heavy metal and the risk of kidney
toxicity but there is also radioactivity from the uranium which can cause an
increased risk of cancer radium 226 and 228 obviously the exposure to those
creates an increased risk of cancers primarily bone cancer and radon in water
is a little bit different animal in that there’s two routes of exposure one being
the radon that off gases into the home and especially exposes people in the
bathroom during showering and poses an increased risk of lung cancer from
inhalation but then there is also increased risk of stomach cancer from
ingestion there is not a drinking water standard for radon in water
the EPA looked at this several years ago for an extended period of time and
ultimately has not established a drinking water standard because of
number of factors that the vagaries of how people are exposed so forth there is
an NRC report on radon in water and then within North Carolina we had an
interagency Committee on radon in water to develop an advisory report back in
2011 in that advisory report they established two thresholds for people to
consider treatment of radon in their drinking water the higher of those is
10,000 picoCuries per liter in water and the lower being 4,000 picoCuries per
liter philip has mentioned the fact sheet that explains what those two
thresholds mean but one of the key findings in that radon water advisory
committee report was that when you look at radon in water you need
to also make sure you’re assessing radon in the indoor air overall so that you’re
attacking the right source of radon so taking all this information into account
in 2016 we began publishing a testing recommendation for private well users
within the county that covered the eastern half of the county where the
rock types we felt were more prone to these types of contaminants and we
developed a specific test recommendation which for the ease of the private well
user we just termed the rads package that’s gone through a little bit of
evolution but at present that rads package that we recommend for well
private well users in the eastern half of the county includes a test for
uranium and tests of gross alpha activity as well as gross beta activity
a test of radon in water and when we’re doing the testing we also drop off a
test kit for radon in air and whether you go through the county and our
testing services or go out to a commercial laboratory this is the
recommendation that we have for well users in the eastern part of the county
and in particular it’s it’s easy for people to forget the fourth test there
of radon in the indoor air in addition we began a rule revision process of our
local rules that govern the permitting and approval of new private drinking
water wells and beginning in March of last year we have added a new testing
requirement for all new wells or wells serving new construction that those
wells must be tested for gross alpha and beta activity ultimately we opted not to
include the radon test as a requirement here we can get into more of that in the
discussion but the lack of a drinking water standard and the lack of
a regulatory program that requires radon resistant construction to protect from
soil vapor issues were underlying the decision not to include radon testing as
a requirement for new wells so we did these things we feel like these were
pretty good steps in the right direction to protect the health of private well
users but as we then sort of look back at a program review looking at that
exceedance rate that we’re seeing for uranium and for radon of 10 to 20
percent of the wells in the county and multiplying that times the 40,000 wells
we have in the county this is what the scope of the problem looks like this is
the the pie chart may imply a level of precision here that is not real but
consider this as a cartoon where we have roughly 40,000 wells in the county and
maybe 6,000 of those are currently contaminated with uranium or other
radionuclides we at this point in 2018 had tested about 800 wells for any
radionuclides at all and confirmed roughly 160 contaminated Wells through
that testing so we’re still looking at several thousand wells in 2018
that were likely contaminated and the users of those wells probably did not
know it we also see just because the geology
does not stop the county line that the scope of this problem is not limited to
Wake County but also impacts our neighboring counties especially Franklin
County to the north of us which has the same Rolesville granite and another
granitic pluton underlying much of the county and similar plutons in other
counties of the eastern piedmont and if we go west we would see others as well
and in fact looking statewide there was some great work done by Ted Campbell
with the North Carolina Division of Water Resources along with Phil Bradley
with the North Carolina Geological Survey and kyle messier was then a
graduate student at unc to assess the susceptibility of private wells to
elevated radon throughout North Carolina and we can see here the purple area and
sort of orange or brown area and Wake County and the center of the map is
essentially our area where we’re recommending or requiring certain tests
for radionuclides and these colors and patterns extend into other areas
throughout the state so again looking at that scope where we have several
thousand wells that are likely currently contaminated and the well users are
likely unaware of this issue we began to think that as a County Health Department
we had some obligation to improve the awareness of this issue in the private
well community and get more people to tests and try to help them through
things so as we looked at how we respond to this issue and get the word out we
considered three key questions one what is our obligation as the health
department what is our capacity and what’s the likely impact on other
agencies and jurisdictions so through to consider those questions we consulted
with a large number of groups within Wake County government within Wake
County private sector but also at the state level and consulted with other
states on how they’ve approached this type of an issue I won’t go through
everything here but through all those folks we in consultation with those
stakeholders we arrived at a few conclusions one was that our we had an
obligation to notify the public and through that we needed to make sure that
our message was accessible to everyone and that resources were available to
everyone that wanted to make use of those resources also looking at the
capacity we realized we do not have the capacity if we were to do a very large
scale outreach campaign it would likely overwhelm our current capacity in a
given year we typically will collect water samples from about 400 or 500
wells and if we were looking at trying to get thousands of people to test their
wells that would easily overwhelm who our current human resources and budget
capacity the county manager’s office and budget office were able to allocate some
funds for a one-time increase to assist us with capacity but this was not going
to we weren’t going to staff up for a large permanent well water testing
campaign and through that we determined that we
really needed to direct well users out to qualified commercial labs as the
primary way of getting their well water tested and lastly in terms of the
impacts on other agencies and jurisdictions we needed to communicate
well to those other agencies and jurisdictions especially our neighboring
counties and officials at the state level about what we were doing so that
when their phones began to rang their to ring they would know where to send
people and how to answer those questions so some additional work on that
ultimately coalesced on June 24th of last year we mailed 19,000 notices out
to the addresses of suspected well users in the eastern half of the county we
don’t have a centralized database of every well within the county but we were
able to use County property records and other GIS layers to identify those
properties that are likely served by private Wells and send mailers to them
we made sure that whenever the property address did not match the mailing
address we sent the mail or to both of those addresses because we’re we suspect
that’s a landlord-tenant situation and we put this mailer out in both English
and Spanish and it contained all of the information that we were going to be
putting on the web and included information about how to get your well
water tested through commercial laboratories and some information about
what the health risk was and why it was important to have well water testing in
addition we know that once you get that mailer you’re going to have questions
and so we needed to have mechanisms for supporting people and getting answers to
those questions we established a dedicated webpage with
a simple URL that people could go to that webpage included an interactive
online map so that people can type in their address and see if they were in
the area where we were recommending these
tests we established a hotline that initially for the first couple of weeks
was 24 hours a day 7 days a week had operators who could speak both English
and Spanish to receive calls and we recognizing that we were going to be
sending individual well users out to commercial labs to collect well water
samples and there were some sensitive aspects of the sample collection we
produced a video of how to properly collect a sample for radon and water
analysis and put that on the website we also at the launch of this campaign held
six general awareness community meetings I think we had about 500 people and all
attend those general awareness meetings so that we repeated the message to them
face to face and we took their questions and then because people have been taking
their own water samples to commercial laboratories and getting the results
back commercial laboratories are not qualified to provide technical advice
about the test results we made ourselves available at a series of monthly
initially weekly and then monthly technical advice sessions where well
users could walk in with a lab report and sit down with one of our well
specialists and have someone walk them through how to read that lab report and
what it means for their health risks and how they might go about reducing those
risks also since this testing is fairly
expensive a few hundred dollars just for the Radiological piece we made some
improvements to an existing program to help lower-income residents afford the
testing they we have a discount program that allows anyone whose income is less
than two and a half times the federal poverty guideline get reduced fees for
testing through the county and from the launch of this campaign into the fall we
actually prioritized the county services so that we only served the lower-income
residents and they did not have to go out to these commercial laboratories and
pay full price there and we streamlined the qualification process for that so
it’s a simple notarized affidavit completed by the resident where they
attest to their own income level and we don’t require them to submit a lot of
w-2s or other documentation in order to qualify for that discount so we did all
this and there was quite a bit of excitement throughout the county and
other people impacted by this campaign but has it worked by the numbers we had
a pretty big response over 350,000 views of our web pages at the dedicated URL
that we set up we had 1300 calls to our hotline within the first few weeks and
we were able to do that without disrupting the normal phone numbers that
we use for scheduling construction related inspections and so forth we
received over 70 requests for financial assistance with testing from
lower-income residents and we had over 500 people attend those community
meetings ultimately we we reached out to the private labs and asked them to
report to us each week how many samples they received from Lake County residents
we don’t have perfect numbers on that but it looks like an additional 1,200
wells were tested during the height of the campaign over the summer so 1,200
Wells is a far cry from the nineteen thousand or so that we estimated ought
to be tested but I will note that that is three times the number of wells that
my staff and I can sample in a given year
so within three months we got three years worth of testing done so that’s a
pretty big advancement and just looking again in a semi-quantitative
cartoon here the scope of the problem in 2018 and is there on the left and in
2020 we have moved the needle quite a bit in terms of the number of total
wells that have been tested for radionuclides and a little bit in terms
of the wells we have confirmed to be contaminated but we still think there
are a number of a few thousand wells in the county that are likely contaminated
and probably have not been tested so we’ll continue to push this issue under
sort of more normal steady-state conditions but through this campaign
we’ve produced a number of advancements in well user support and well water
testing one of these being an improved and streamlined process for the
financial assistance with testing also with some help from the state of New
Hampshire and counterparts in Vermont and through the US EPA we were able to
implement an online test interpretation tool called be well-informed in a
version that’s customized for Wake County and based on state
recommendations specific to North Carolina
and there is a link in this slide I think Philip is going to make these
slides available to anyone who attended today later on and you’ll be able to
click on that link and go in and see Wake County’s customization of be
well-informed but you can also go and compare how New Hampshire Wyoming couple
over there a couple of other states have used that tool to allow users to enter
their test results and receive a report that tells them what’s wrong with their
water what their health risks are from those problems and what fixes they might
want to consider in order to reduce their risk our technical assistance
meetings have also been a very helpful and popular forum for getting technical
assistance it’s a little more efficient for us than having to talk to each
individual for 20 or 30 minutes on the phone and walk them through their
results so we’re going to be continuing that as a regular part of our program
now into the future in addition because of our outreach to stakeholders during
the planning of this campaign we now have much greater awareness about this
issue among the various professionals who support well users our neighboring
county health departments are aware of this issue and because we had to
privatize our response to it the resources that we’ve put online have
been approachable to to their residents as well we’ve been doing quite a bit of
outreach to home inspectors and Realtors so that when people are at a point of a
real estate transaction they’re aware that there may be other tests they want
to run beyond what the normal VA or FHA loan requires like coliform and nitrate
but also these radionuclides we’ve provided training to water
treatment contractors and plumbers in the mitigation of these issues so that
professionals that well users will be going to to mitigate these problems are
aware of the issue and have received some training and how to do it what the
cautions and caveats are around mitigating these particular contaminants
and we’re also making inroads with the medical community advising them about
these things our conversations with the medical community during the planning
stage showed us that if physicians and ER professionals were thinking about
well water at all they tended to be thinking about fluoride in terms of
childrens dental health and bacteria in terms of intestinal illness but they
were generally not aware of the prevalence of uranium in well water
within Wake County and the potential fairly short term health risks
associated with uranium in addition we’ve made some progress in educating
commercial labs about how to serve private well users better conversations
with private labs with with one lab during the planning phase of this
indicated that if a private well user approached that lab and wanted testing
they would give that customer a list of all regulated drinking water
contaminants and ask them which ones they wanted we’re trying to encourage
those labs to use simple shorthand with well users and to adopt the same
recommended tests that we have on our website within easily named packages so
when a well user comes in and says I’ve never had my well water tested we tell
them they should get their first-timers package and that test that package
includes certain tests we’re encouraging the commercial labs to think in those
same terms and include those same recommended tests likewise in terms of
the radionuclides we have something called the rads
package and it contains those three water tests or it includes those
three water tests uranium grouse alpha radon in water but we give it an easy
user-friendly name and we’re encouraging commercial labs to adopt a similar
approach so what’s next we’ll be continuing this push one thing we found
was that low-income residents seem to be responding to the campaign at much lower
rates than higher income residents overall it looks like we had about a
seven percent response rate to our mailers but low-income residents that
response rate is less than two percent of the estimated population of
qualifying households so through the end of February we’re offering free well
water testing for households who qualify at that two-and-a-half times the federal
poverty guideline threshold which is about sixty five thousand dollars for a
family of four we’re continuing our training for the supporting
professionals giving presentations to Realtors home inspectors and also at
Grand Rounds at one of the major hospitals here in the area next month we
are working with those commercial labs to try and get some data summaries
unfortunately we’re not able to get the results directly from them because
that’s part of a private business transaction and their attorneys and our
attorneys have both advised us that we shouldn’t be trying to get that data
directly but we are asking them to provide us with summaries of what
percent of the samples that they received exceeded thresholds for these
contaminants and we’re currently trying to identify resources to help affected
well users one of the biggest challenges in this is that we can make the testing
affordable or even free but if you cannot afford the testing then and you
need mitigation on your well you are likely not going to be able to afford
the mitigation we have identified some financial
assistance programs to help with that but there is no silver bullet in this
North Carolina has quite a few programs aimed at protecting private well users
from man-made contamination but naturally occurring contamination is
generally not covered by those programs offered by North Carolina and even
through the EPA like through Superfund the focus of that is on man-made
contamination and that in particular is an issue we see that we like to see
taken up statewide going back to this map of areas of susceptibility to radon
in groundwater the issue we face here and the financial assistance needs for
residents of Wake County is not limited to Wake County but it’s likely going to
be felt in other places and we could overlay onto this other maps such as
susceptibility to arsenic contamination in other parts of the state and those
well users are going to have similar needs for financial assistance a half
give credit to a lot of states and I’m not going to read this slide don’t worry
but when Philip provides this deck of slides you’ll be able to click on the
links here and actually go directly to these reports so we benefited from years
worth of work by others in assessing this issue and providing guidance in
particular I will note again the radon and water advisory committee report and
Ted Campbell’s excellent leadership on that and I’ll note also the USGS
circular about the quality of water from domestic wells again I think highlights
the point that Wake County is not unique in facing these naturally occurring
contaminants this is probably a national issue in general and then the rest of
these are a number of guides to radionuclides how to protect your well
water from them and reduce the levels in your well water with that I will turn it
over to Philip and open up for questions if we have time thank you it’s great if
you have questions please feel free to type them in the chat box people typing just to make a note this
is Philip again so I will acknowledge Evan I don’t know if you knew this or
not but I’ve been in conversations with Ted Campbell and certainly there are
other people for example Rick Wooten from the North Carolina Geological
Survey here in Asheville area about reaching out to those areas that have
similar geological formations that are identified there in the advisory report
that you referred to so that is something that’s going on I noticed that
someone says they don’t see any reports or slides to download I’ll email them
out to everybody as well just in case you’re not able to download them from
the chat box we have three different questions now Phillips okay I’m is there
a direct indicator between uranium and Gross Alpha so there is a relationship
uranium is an emitter of gross alpha activity and the EPA’s small entity
compliance guide for the radionuclides rule provides some useful strategies for
interpreting gross alpha initially we implemented our testing recommendations
just using gross alpha and radon in water but we found that because radium
226 is also a contributor to gross alpha well users were having to come back for
follow-up testing to determine specifically how much uranium was
contributing to their gross alpha and how much was radium so we felt like
running the uranium and the gross alpha together was an effective way of finding
out how much uranium was contributing and getting an approximation of the
radium it’s not a perfect way of measuring radium but the radium test
itself is quite expensive to all the others and we felt like
providing a low barrier to entry was important for this testing in in our
testing it looks like uranium is the primary contributor to our gross alpha
readings but different areas with different geology might have more
prevalence of radium and so specific radium testing might be more important
there I would point out like New Jersey’s requirements for point of sale
testing of wells they actually have different recommendations for the
radionuclides or different requirements for the radionuclide testing depending
on which county you’re in because there’s different ratios of uranium and
radium okay here’s another what are some of the recommended water treatment
choices at a low cost well it really depends on the specific mix of
radionuclides in your well water and other what we call confounders like iron
manganese and hardness if your problem is with mineral radionuclides then
reverse osmosis is a fairly low cost system because you can install that just
in the kitchen and treat the water there but if you have radon in your water at
levels that needs to be treated then you’re going to have to go with a whole
house solution and that’s going to increase the cost quite a bit and we
really can’t point to a recommended water treatment choice until you know
each person has their specific test results should individuals and low
moderate areas be concerned about testing their water wells
are there well water I’m gonna assume that that’s referring to the
susceptibility map yes in terms of in Wake County we have included that
moderate susceptibility area in our testing recommendations and so okay take
that for what it’s worth all right what is your recommended
retest frequency that’s an excellent question from what we have seen most of
the testing for radionuclides in private wells has been one-time or the testing
that’s been published has been from one time campaigns and we haven’t seen a lot
of repeat testing to tell us what the interval is and how much variability you
see over a year or more generally I think we would suggest that people who
are in the recommendation area they want to retest every year or two years if you
if you get clean results then maybe you retest in two years to make sure there’s
not been any changes but there’s not a lot of real solid guidance out there yet
have you seen in the Reds package any evidence that supports the EPA’s
outdated information that 10,000 picoCuries per liter and water generates
one because later radon in air it’s a little bit of a loaded question but we
don’t so the radon in air testing that we make available to well users actually
becomes a transaction between them and the testing company we drop off a kit
they mail it off and we generally don’t see the results of that there is this
rule of thumb out there about 110 thousand picoCuries per liter of radon
in water correlates to one pika carry per liter in air but that’s really going
to depend on how the occupants of that home use water in that home if they take
long hot showers it’s going to be different than if they take very short
showers just to psych one behavior that’s highly variable can you discuss
the four thousand and ten thousand picoCuries per liter
that you mentioned in a little bit more detail and as well water remediation
recommended at the 4000 level or the 10,000 and somebody else has said that
they used 2000 as recommended action yeah
so we’re I’m trying to follow the advice from the radon and water advisory
committee that North Carolina convened several years ago their recommendation
was that at levels between 4,000 and 10,000 well users may want to consider
treatment of that water in conjunction with dealing with an overall indoor air
problem and that at 10,000 or higher treatment was recommended again in
conjunction with the overall indoor air issue it’s a little bit gray but I think
essentially it’s a much stronger recommendation to treat above 10,000 and
sort of a advisory to consider it between 4,000 and 10,000 let’s see
assuming that treatment is installed what ongoing testing strategy is
suggested to confirm that the treatment is really working so number one thing we
would say is to follow the treatment installers recommendations for retesting
but definitely get a confirmation test once the system is installed we have
seen a number of systems go in that were partially effective but did not achieve
the outcomes that we would like to see or that the even that the Installer was
expecting to see so you want to get those issues worked out right away after
installation and then after that it’s really going to depend on the particular
system that’s installed and what the lifespan
the media and other components of that system is how frequently you’ll want to
retest it okay and then we’ve got two more and then I
think we’ll probably break it off in any other questions we can try to answer via
email but how is a thousand people carries per liter action level
established so I think this is the maybe he’s referring to a 10,000 people maybe
perhaps just a zero there I’d really have to point you to that radon in water
advisory committee report they that team looked at a lot of studies including the
National Research Council report on radon in water and took a lot of
information into account in coming up with that so rather than try to
summarize all that here I would point you back to that okay and just as a
follow-up what are the what are the dangers of drinking contaminated water
well again depends on the contaminant that you’ve got present but in terms of
radionuclides many of these things are associated with an increased risk of
cancer from chronic exposure so repeated exposure over a long period of time but
as we understand it from reading information that the talks guide for
uranium the shorter term risk with uranium is reversible kidney toxicity
from uranium’s behavior as a heavy metal and then I guess there well there’s one
more question and then this will be it and didn’t let Philip just sort of wrap
it up but would it be possible to have well water reading that’s data that’s at
10,000 people Curie’s per liter and yet had the indoor air rating be below the
action level of floor right and if so would water treatment you recommend it I
think it’s highly possible to have that happen
and yeah generally we we think people should look at the cost of remediation
of water versus the cost of remediation of a soil vapor issue and choose the one
that provides the greatest overall radon reduction for the least cost and in that
situation your well I can’t speculate on a particular situation but Philip do you
want to sort of wrap it up and tell them what you’ve shared and talk about the
the one on February the six that will go into more depth about um water as well
yes thank you Sarah and Evan thank you again so much for sharing your expertise
experiences I think this is going to be significant wake up for some folks other
areas of the country but also the experience that you shared at the
process that you’ve been dealing with this is I believe spot I’m thankful that
you’re being willing to share that with regard to some of the questions I don’t
know if everyone is able to download or know how to download those things that
I’ve uploaded to the chat box but what is happening on February the 6th and
that’s a the next webinar in the February series and that is Jay Highland
from the Maine the state of Maine’s radon program they’ve been actually
addressing radon and radionuclides in well water for a few decades so they’re
actually going to share what are some of the treatment systems for radionuclides
and radon in water so that the details will come out in that the radionuclide
the fact sheet someone asked about health impacts so i’ve uploaded that
that is from another division of Public Health in North Carolina so you’ll be
able to see those health impacts and that fact sheet and then
there is there’s a number of other things so and hopefully you’ve also
received heavens slides so you’ll be able to link to those resources that he
has referred you to if not email me and I’ll email it out to you there folks
asking in questions about personal homes so forth feel free to give me a call and
I will help you with that process so again Sara Evan thank you so much thank
you everybody for participating and hopefully I’ll see you all in the
February workshops or webinars thank you thanks

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