HomeMy WebLinkAboutPSD-008-16 Clarington
Planning Services
Report
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Report To: Planning and Development Committee
Date of Meeting: January 11, 2016
Report Number: PSD-008-16 Resolution: '
File Number: PLN 26.14.1 By-law Number:
Report Subject: Clarington Transformer Station —Additional Professional
Services
Recommendations:
1. That Report PSD-008-16 be received; and
2. That all interested parties listed in Report PSD-008-16 and any delegations be
advised of Council's decision.
Municipality of Clarington
Report PSD-008-16 Page 2
Report Overview
Council requested a costing estimate for additional work relating to private wells and
tritium testing from the peer review hydrogeologist for the Surface and Groundwater
monitoring program being carried out by Hydro One on the Clarington Transformer Site
and surrounding area.
1 . Background
1.1 At the December 7th, 2015 Planning and Development Committee meeting, the
following Resolution #PD-079-15 was referred to Staff to provide a report on the
estimated costs of a consultant's report regarding the general source of the
contamination and cost of tritium testing/analysis:
That Staff request a report from Steve Usher, SLR Consulting, to obtain his
opinion for the reason for the contamination of the shallow wells near the
Clarington Hydro One Transformer Station.
1.2 The Minister of Environment approved the Environmental Assessment for the
Clarington Transformer project in January of 2014. To address ongoing concerns
from community members and residents, Hydro One proposed to Clarington to
fund a peer review of their Surface and Groundwater monitoring program. Council
accepted and Mr. Steven Usher of SLR Consulting (Canada) Ltd. was retained as
the peer review consultant.
2. Peer Review Findings in relation to Private Wells
2.1 In October 2015, Mr. Steven Usher of SLR Consulting (Canada) Ltd. provided his
peer review on the information generated by Hydro One and their consultant
Stantec in relation to the Surface and Ground Water Monitoring Program. The
peer review included information from all parties, including Hydro One, Stantec,
G360 Group, Enniskillen Environmental Association, the Conservation Authority,
Clarington, the Ministry of Environment and Climate Change and the Oak Ridges
Moraine Coalition YPDT-CAMC.
2.2 Drilling of the deep borehole in November 2014 confirmed the absence of a
shallow sand lens at location MW5-14 at the western perimeter of the Hydro One
Clarington Transformer Site. However, below the east half of the site, extending to
the other side of the watershed divide and further downgradient east from the
divide, a sand lens exists and hosts local private wells that are part of the
monitoring program. SLR maintains that this sand lense is likely the Mackinaw
layer; Hydro One maintain that it is not continuous.
2.3 The reason private wells in the Farewell Creek Watershed were included as part of
the private well monitoring program is an evolution of the original program. At the
first Clarington Community Liaison Committee (CLC) meeting on June 5, 2014,
residents expressed an interest in having the private well monitoring program
expanded from its initial scope, which targeted only well owners adjacent to the
Clarington Transformer Station site. In recognition of the concerns raised by
Municipality of Clarington
Report PSD-008-16 Page 3
private well owners located further afield, Hydro One accepted this request and
extended the scope of the program to include interested residents within an
approximate 1,200 metre radius from the property boundary of Hydro One lands
where the Clarington Transformer Station is located.
2.4 As part of the peer review presented in October 2015, SLR concluded that the
presence of a strong groundwater divide exists at surface and depth between the
site and the closest Mackinaw wells in the Farewell Creek tributary near Langmaid
Road. Further, it concluded the private wells are not at risk from the Transformer
construction site, ongoing monitoring will continue.
2.5 Individual residents have allowed Hydro One/Stantec access to their properties for
the private well monitoring program and the results are provided directly to the
residents. We have been informed that some private wells experienced high
levels of coliform and E-coli in the fall 2015 round of testing. The Municipality of
Clarington, and hence our peer review consultant do not receive the results of the
private well monitoring program because of privacy concerns under the Freedom
of Information and Privacy Act.
2.6 According to the Durham Health Unit elevated coliform bacteria and E-coli
readings is not uncommon in shallow private wells. The Health Unit has a number
of resources on their website to assist private wells owners with common issues.
Attachment 1 to this report is the information on Well Safety including bacteria and
E-coli from their website.
2.7 Hydro One included bacterial analysis as part of the Private Well Monitoring
Program to help provide additional information to residents about their well water,
as it is used for drinking and household purposes. However, the scope of the
approved Groundwater and Surface Water Monitoring Program does not include
testing for bacteriological parameters for the monitoring wells located on-site as
they are not used as a potable water source.
2.8 At the November 30, 2015 CLC meeting, Mr. Usher asked a number of questions
on behalf of the residents with regard to contamination from the construction site
being able to affect the private wells in the Farewell Creek watershed. Mr. Brant
Gill of Stantec the consultant for Hydro One confirmed that no mechanism for
contamination on the construction site existed for water at surface or below ground
to affect the Farewell Creek private wells. (A recording of the meeting is available).
In addition, Mr. Gill indicated that bacteria is present anywhere at surface, the
private well testing is performed on the 'Yaw" water from the well (prior to any
internal treatment private residents may provide within their homes).
2.9 Council asked SLR for a proposal to on the estimated costs of a report regarding
the general source of the contamination (Attachment 2).
3. Tritium Testing
3.1 In August 2015, members of the EEA conducted some well sampling at PW1,
PW2 and PW10 for the purpose of tritium testing. Tritium is a rare isotope of
Municipality of Clarington
Report PSD-008-16 Page 4
hydrogen, with a half-life of about 12.3 years. (That is, for example, a
concentration of 100 Tritium Units (TU) would be reduced to half (50 TU) in 12.3
years.) Tritium is present in rain water and has been elevated since the 1950's
when atmospheric testing of nuclear devices drove up the natural values (a
maximum value of about 3000 TU was recorded in 1964). A record has been kept
of atmospheric tritium since 1953, and provides a unique tool for the age dating of
water. Tritium is not a contaminant, but due to its known rate of decay makes an
excellent tracer for dating water. Although tritium from this source has dropped
dramatically since this atmospheric testing was stopped in the early 1960's, levels
still have not returned to background (pre- nuclear testing) levels and are presently
around 14 TU. In recent decades, nuclear plants, which use lake water for cooling,
have low levels of tritium release. This second source means that background
levels will remain above pre-nuclear testing levels. (Attachments 3 and 4 provide
background information on Tritium from Durham Health Unit and the Canadian
Nuclear Safety Commission).
3.2 The tritium sampling conducted by the EEA has provided useful information. A
more complete picture of the site itself could be made if tritium sampling were
conducted in the onsite monitors as well.
3.3 Dr. Cherry and Dr. Clark questioned the preliminary conclusions drawn by Mr.
Usher in his Peer Review. Both submitted letters to Council calling for additional
work to be carried out in relation to the Tritium sampling. Following Mr. Usher's
Peer Review presentation he verbally recommended to Council that to confirm the
preliminary results of the Tritium testing six additional shallow wells, six additional
intermediate and six additional deep aquifer wells be tested, three in each horizon
upgradient and downgradient.
3.4 Council in receiving the peer review report on October 13th, 2015 passed the
following
Therefore be it resolved that the scientific representatives of Hydro One, the
Municipality of Clarington, the EEA and the Central Lake Ontario
Conservation Authority, including, but not limited to: Dr. Rick Gerber, Dr. Ian
Clark, and Dr. John Cherry, be asked to meet to provide an analysis of the
data on all 23 private wells, three blind samples, and ten site groundwater
monitors for sampling and measurement of tritium and helium isotope
concentrations;
That Hydro One be asked to cover the cost of this one-time sampling and
testing, in the spirit of working towards a solution;
That the four parties prepare a joint scientific report interpreting the results,
including dissenting opinions;
That Clarington request that the Minister of the Environment and Climate
Change amend the terms of the Environmental Assessment conditions to
require that Hydro One submit an addendum to the Environmental Site
Report to address the results of the recent studies showing elevated levels of
tritium within the framework of a conceptual model that explicitly assesses
Municipality of Clarington
Report PSD-008-16 Page 5
groundwater connectivity among shallow, intermediate and deep aquifers,
and identify changes to the Permit to Take Water to require monitoring of
tritium, and to be consistent with the addendum;"
3.5 The Ministry of Environment and Climate Change provided a letter on November
27, 2015 in response to this request indicating that "...the current program is
satisfactory and does not consider the tritium levels found in local wells to be
unexpected. The Ministry does not think it is likely that the underlying aquifer is
being recharged directly through the till cap. The tritium concentrations indicated
that the groundwater recharge, corresponding to the lower concentration of tritium
found in the wells, is likely coming from up-gradient sources a number of
kilometres to the north of the site. The shallow dug wells are typically recharged
locally, and more recently; this is why their tritium concentrations are more
elevated."
Further, the Ministry letter indicated that they had no objections to Hydro One
carrying out tritium testing; however, they did not view it as necessary.
3.6 Hydro One provided a subsequent letter, dated December 4, 2015 indicating that
"tritium/helium-3 sampling would not provide additional information relevant to the
objectives of the Monitoring Program and construction or operation of the
Clarington Transformer Site. Hydro One will continue to implement its on-site
Monitoring Program and the private well monitoring program and will continue to
review any requests from the Municipality or other stakeholders."
3.7 Attachment 5 is the SLR proposal for the cost of tritium testing/analysis; including
the methodology for carrying out this work.
4. Concurrence
Not applicable.
5. Conclusion
5.1 The purpose of retaining a peer review consultant was to assist with understanding
the technical information and to have an independent advisor monitor the practices
and methodologies being employed during the construction of the Clarington
Transformer Station. To date, the observations, recommendations and
conclusions by Mr. Usher of SLR Consulting (Canada) Ltd. have required
additional work by Hydro One and their consultants to demonstrate that the
conclusions of the Environmental Assessment and Permit to Take Water are
reasonable and conservative.
5.2 Council and residents were concerned for the safety of private residential wells in
the vicinity of the transformer construction and Farewell Creek. To date Mr. Usher
has advised that the transformer construction has had no adverse impact on
residential wells and discharge to the creek as demonstrated by the recent
monitoring report.
Municipality of Clarington
Report PSD-008-16 Page 6
6. Strategic Plan Application
Not applicable.
Submitted by: Reviewed by:
a id J. Crome, MCIP, RPP Franklin Wu,
Director of Planning Services Chief Administrative Officer
Staff Contact: Faye Langmaid, Manager of Special Projects, 905-623-3379 ext. 2407 or
flangmaid(c�clarington.net
Attachments:
Attachment 1 — Durham Health Unit information on bacteria and a-coli
Attachment 2— SLR Proposal for opinion for the reason for the contamination of the
shallow wells near the Clarington Hydro One Transformer Station
Attachment 3 — Durham Health Unit information on Tritium
Attachment 4 — Canadian Nuclear Safety Commission information on Tritium
Attachment 5 — SLR Proposal for tritium/helium 3 testing
The following is a list of the interested parties to be notified of Council's decision:
Brad Bowness, Hydro One
Clint Cole, Enniskillen Environmental Association
Drs. John Cherry and Beth Parker, Group 360, University of Guelph
Dr. Rick Gerber, YPDT-CAMC
Chris Darling, CLOCA
Steven Usher, SLR Consulting (Canada) Ltd.
DJC/FL/df
Attachment 1
Municipality of Clarington Report PSD-008-16
Well Water Safety
Contamination of Well Water
Pathways of Contamination
In aquifers,contaminants and recharge waters can follow similar pathways and can contaminate the groundwater
in the following ways:
• spills on the ground (fuel and pesticide spills) Ho e head Diesel Barn Shed
Storage
Septic Feild
• injection into the ground (septic leaching beds, poorly
maintained wells, disposal of waste in wells)
• improper handling of industrial solvents and --
chemicals(varsol and wood preservatives)
�3round Water
• leakage from wastes(manure,wastewater, septic clay
[Aquitard] r
tanks and landfills)
• leaking underground and aboveground fuel storage
tanks
• movement of groundwater between contaminated and clean aquifers
• over-application of soil amendments such as manure,commercial fertilizers or pesticides.
Bacteriological Contaminants
What are Total coliforms?
• Generalized group of bacteria found throughout the environment including soils, � ±
vegetation, and in human and animal feces. t • .`; ,��►+
• Their presence may indicate a problem with your water supply, possibly
010, 0
through surface water contamination.
What is E. coli?
• A group of bacteria that live in the intestines of warm-blooded animals
• Their presence indicates recent fecal contamination such as sewage, and that _--
there is a problem with your water supply.
http://www.durham.ca/health.asp?nr=/departments/health/health protection/wellWater/c
ontamination.htm&setFooter=/includes/health/healthFooterWelLinc#bac
Attachment 2 to
Municipality of Clarington Report PSD-008-16
SLR*'
5 January 2016
Ms. Faye Langmaid
Municipality of Clarington
40 Temperance Street
Bowmanville, Ontario L1 C 3A6
Proposal No.: 209-40541
Dear Ms.Langmaid:
RE: North Clarington (in Proximity To The Clarington Transformer Station)
- Bacterial Well Contamination Study
In the autumn of 2015, sampling of private wells by Hydro One revealed bacteria levels in many
shallow wells and some deep wells in the community. These wells are thought to be outside of
the groundwater flow field associated with the Transformer Station construction, based on the
Stantec reports. However, the municipality is not privy to actual well locations due to privacy
reasons so is unable to assist residents in any way. Recently the Standing Committee passed
Resolution #PD-079-15, which stated:
That Staff request a report from Steve Usher, SLR Consulting, to obtain his opinion
for the reason for the contamination of the shallow wells near the Clarington Hydro
One Transformer Station.
We have spoken with just one resident, and read in the Toronto Star of another resident's bacterial
count. Like the Municipality, we too are not privy to the actual results. These results are listed in
the recent Hydro One monitoring report prepared by Stantec Consulting but are not identified by
location. The wells are on private property. Without access to the location specific data, and
without access to the properties in question to examine their wellhead construction and
operational conditions of the wells, we cannot reliably form an opinion on the reason for the
bacterial contamination on an individual well basis. Both Stantec Consulting, and the resident's
themselves know which sampling results belong to which well. So it is a relatively simple process
to obtain the information if permission is granted, but we have no control on whether permission
would be given or not.
You will recall that our annual report in late September concluded that wells are safe from the
Transformer site. This was based on the physical flow system. Most of the wells sampled by
Hydro One are in the Farewell watershed to the east. There are no shallow wells downgradient
from the site. Bacteria cannot travel up and over the hills to get to these wells, because the water
flows the other way. The bacteria found in the sampling program are either Total Coliform, or a
member of that group, called E-Coli. Total coliform is naturally occurring and does not have to
come from animals. E-Coli is definitely from animals (including humans, dogs rodents, birds and
cattle). Our Provinical Standards call for no E-Coli in treated water (not raw water, that is a
common misapplication). In our experience, and well documented in the literature, raw water
often contains coliform, particularly in shallow wells, and most prudent rural residents have some
SLR Consulting(Canada)Ltd. 200-300 Town Centre Boulevard,Markham,ON L3R 5Z6
T:905.415.7248 F:905.415.1019
www.sirccnsulting.com
Municipality of Clarington Proposal No. 209.40541
Clarington North Well Contamination Concerns January 2016
form of treatment, including many of the residents near this site.' Under the new GUDI regulations
being developed now by the province, Total Coliform will no longer be used as an indicator
because it is ubiquitous in the natural environment.
Coliform bacteria typically lives as long as 50 days outside of a warm host, and generally do not
survive that long. Groundwater travel times are quite slow, in the order of less than 10 m a year.
This means that bacteria would only travel less than two metres during the 50 day lifespan in such
conditions. Therefore the presence of bacteria in a shallow well means that the source is only a
few metres away on any given property, and the cause is usally domestic or wild animals or birds.
Finally, the presence of bacteria in private rural wells is very common right across Ontario and
elsewhere, as many studies have shown.
To address the need for Council to have an opinon on bacterial contamination it would be best to
use the actual sampling results, coupled with an examination of the property and well in question.
Access to the information and property would have to be arranged for. In the absence of access
to this information, a general opinon as expressed above can be prepared with existing knowledge
of bacterial distribution patterns and characteristics, and a sense of the lay of the land and
hydrogeologic properties, such as is contained in the existing reporting and other technical
sources.
The estimated cost to provide a general opinion would be in the order of $5,000 plus HST. If
specific landowners were willing to participate, the general cost per well to review the data,
examine the wellhead and operation, and provide a written opinion in the context of the physical
setting and relationship to the Transformer Site would be about $1,500 per well plus HST.
Assuming 10 wellowners with bacteria problems came forward, this would total $15,000 (plus
HST). The estimated cost of do this work would therefore be about $20,000 plus HST,
dependant upon the degree of participation.
We trust this submission provides the information you were seeking.
Yours sincerely,
SLR Consulting (Canada) Ltd.
Steven Usher,M.Sc.,P.Eng.,P.Geo.,FGC
Seniro Hydrogeologist
SJuisu
' To be clear, Hydro One endeavours to sample the raw well water at each residence, which is normal
practice. That is, the sample is taken from a tap prior to the water entering the homeowner's particular
treatment system. In this way potential changes to the natural water quality can be properly assessed.
SLR 2
Attachment 3
Municipality of Clarington Report PSD-008-16
FACrS
HEALTH DEPARTMENT • •
Background
Tritium is a radioactive form of hydrogen that is created naturally in the environment, and is also released in very
small amounts by Canadian nuclear facilities as tritiated water.
Since radioactivity poses a health risk,the Ontario government has placed limits on the allowable amount of tritium
in drinking water.
Tritium levels in drinking water obtained from Lake Ontario are very low and have never exceeded the Provincial
limit.
How does radiation affect my health?
Exposure to any radiation source can result in an increased risk of cancer, genetic defects and reproductive
effects. Since we are exposed to radiation from many natural(e.g., radon gas in soil)and human sources(e.g.,
medical x-rays), it is important to control our total radiation exposure, not just our exposure to one source.
We can be exposed to tritium by eating and drinking contaminated food and water, and breathing contaminated air.
Where does tritium come from?
Tritium is produced naturally when cosmic radiation and gases in the atmosphere interact.
Tritium also originates from human activities such as nuclear weapons testing which has slightly contaminated all
surface water supplies around the world.
Canadian designed nuclear reactors(e.g., CANDU)also produce tritium.An accidental release of"heavy water"
used to cool the reactors can result in the release of tritium into the environment. Small amounts of tritium are also
released into Lake Ontario during the normal operations of the nuclear generating facilities.
How much tritium is in my drinking water?
In Canada,the average tritium concentration in drinking water ranges from 5 to 10 becquerels per litre.The
Becquerel is an international measure of radioactivity.
Water samples taken near Pickering and Darlington Nuclear Generating Facilities occasionally have a tritium
concentration of approximately 20 becquerels per litre which is well below the interim Provincial limit for tritium of
7,000 becquerels per litre in drinking water.
What is being done to make sure tritium levels stay low?
Ontario Power Generation in association with Provincial and Regional authorities has developed a comprehensive
emergency response plan in the event of an accidental tritium release to protect the health of the residents of
Durham Region.
Daily samples of drinking water are obtained from all water treatment plants within 20 kilometres of the two nuclear
generating stations on Lake Ontario.The Radiation Protection Branch of the Ontario Ministry of Labour tests these
samples for tritium content. Ontario Power Generation (formerly Ontario Hydro)also tests water samples as part of
its own monitoring program and the Health Department closely monitors the results.
More information can be obtained from
Durham Region Health Department, Environmental Help Line 905-723-3818 or 1-888-777-9613
http://www.durham.ca/health.asp?nr=/departments/health/facts_about/tritium.htm&setFooter=/includes/health/healt
hFooter.inc
Attachment 4 to
Municipality of Clarington Report PSD-008-16
t
Fact Sheet
Tritium
December 2012
Quick Facts
Tritium is a radioactive form, or"isotope", of hydrogen. It has two . Tritium is a radioactive form
neutrons where regular hydrogen does not have any, which makes of hydrogen that occurs both
tritium unstable and therefore radioactive. It is produced naturally naturally and as a by-product
from interactions of cosmic rays with gases in the upper of the operation of nuclear
atmosphere. It is also produced as a by-product of nuclear reactors. reactors.
Like all radioactive isotopes, tritium decays. As it decays it gives . One of the more common
off, or emits,beta radiation. uses of tritium involves glow-
in-the-dark lighting and
One of the more common uses of tritium involves glow-in-the-dark signs.
lighting and signs. Tritium gas is combined with phosphor to
create luminescence. The light source does not require electricity . Tritium exposure can pose a
or electrical wiring, making it ideal for exit signs, emergency health risk if it is ingested
lighting in commercial buildings and airplanes and for airport through drinking water or
runway lights. food, inhaled or absorbed
Tritium is also used as a tracer in biomedical and academic through the skin in largequantities.
research. Some countries use tritium as fuel for thermonuclear
weapons, although Canada is committed to nuclear non- . The CNSC regulates releases
proliferation. In the fixture,tritium may also be used to generate of tritium by nuclear reactors
electricity in fusion reactors which are currently under and tritium processing
development. facilities to ensure the health
.
The Canadian Nuclear Safety Commission (CNSC)regulates and safety of workers andthepublic, and the protection of
releases of tritium by nuclear reactors and tritium processing the environment.
facilities to ensure the health and safety of workers and the public,
and the protection of the environment.
' Canadian Nuclear Commission canadienne CWaaa
Safety Commission de surete nucleaire
Tritium
Tritium in Drinking Water
The most common form of tritium is tritiated water(HTO). This happens
when a tritium atom replaces a hydrogen atom in water(H2O)to form HTO.
HTO has the same chemical properties as water and is also odourless and
colourless.
The standard international unit for measuring radioactive decay or
radioactivity is the becquerel (Bq). The amount of tritium in water is
measured in becquerels per litre (Bq/1). Water with a tritium activity of 1 Bq/1,
contains less than I tritium atom per 100,000 million million (1 in 1017)
molecules.
The highest average annual tritium level measured in the drinking water of Canadian communities neighbouring
nuclear facilities is about 18 Bq/1. This is well below drinking water limits recommended by Health Canada of
7,000 Bq/1.
Tritium in the Body
Some of the tritium released into the environment will be naturally incorporated into nutrients such as
carbohydrates, fats, or proteins. This is called organically bound tritium(OBT). OBT can enter the body directly
by eating tritiated food. OB'C poses a slightly greater health risk because as an organic material,the body will
retain it longer than tritiated water. This means that there is a greater likelihood that the tritium atom will decay
while in the body and possibly cause damage. Generally speaking, OBT is at much smaller concentrations in the
body than tritiated water.
Health Effects
Tritium is a relatively weak source of beta radiation. The beta particle itself does not have enough energy to
penetrate the skin. However, it can pose a health risk if taken directly into the body in extremely large
quantities; for example, a person would need to take in billions of becquerels before seeing a health effect.
Tritium molecules can enter the body by breathing air containing tritium, or by ingesting tritiated food and
water. Tritiated water can be absorbed through the skin like regular water. Most tritium leaves the body as
tritiated water in urine,breath moisture and perspiration. Most inhaled tritiated hydrogen gas is exhaled
immediately.
A radiation dose from tritium is like a radiation dose from any other type of Radiation Dose
radiation, including natural background radiation and doses received during The effect of the
medical procedures. In Canada,members of the public receive annual doses of radioactivity on the body is
radiation from tritium of 0.0001 to 0.013 millisieverts (mSv), although very few, called a radiation dose and
if any, members of the public receive doses in the upper end of this range.Near is expressed in
nuclear facilities, where tritium levels are slightly higher, the average annual sieverts(Sv),or more
dose to adults is about 0.0015 mSv. These doses are well below the public dose commonly,in millisieverts
limit of 1 mSv as set in the Radiation Protection Regulations, and the average (mSv),which are one one-
Canadian dose due to natural background radiation of 1.8 mSv. thousandth in size.
2 Canadian Nuclear Safety Commission
Tritium
Studies have not shown health effects at a chronic exposure below about 100 mSv. The regulatory public dose
limit of 1 mSv is equivalent to 1% of this amount.
Regulating Tritium
Small amounts of tritium are released to the environment mostly from reactor operation and maintenance and
during the manufacture of tritium light sources. The CNSC imposes Derived Release Limits (DRLs)that restrict
the amount of radioactive material that may be released. Releases must also be "as low as reasonably
achievable"—a concept known as ALARA—and as a result, actual releases of tritium from nuclear facilities
have typically been less than 10% of the DRL.
The CNSC requires all Canadian nuclear operators to provide quarterly reports on monitoring results for routine
radioactive discharges, and annual reports on environmental monitoring programs.Licensees are also required
to report any accidental or unmeasured releases of nuclear substances into the environment.
Tritium Studies Project
In 2007,the CNSC launched
the Tritium Studies Project, a
multi-year research project
on tritium releases in Canada } ,
and an evaluation on the best
practices of tritium
processing facilities around MMMIMMMMM
the globe.
The project has expanded the body of knowledge on tritium. Six studies have been published, as well as a
synthesis report that rolls up the conclusions and makes recommendations for regulatory improvements. These
include actions to make the regulation of tritium even safer,protect future drinking water resources and enhance
environmental compliance monitoring.All of the studies are available on the CNSC Web site, in the Reading
Room.
To better regulate tritium releases in Canada,the CNSC continues to conduct research on tritium environmental
behaviour and health effects in technical collaboration with several national and international partners.
For more information:
1-800-668-5284 (in Canada)
613-995-5894 (outside Canada)
info(cD_cnsc-ccsn.gc.ca nudearsafety.gc.ca
Canadian Nuclear Safety Commission 3
Attachment 5 to
Municipality of Clarington Report PSD-008-16
5 January 2016 r
SLR40
Ms. Faye Langmaid
Municipality of Clarington
40 Temperance Street
Bowmanville, Ontario L1 C 3A6
Projposal No.: 209.40542
Dear Ms.Langmaid:
RE: North Clarington (in Proximity To The Clarington Transformer Station)
- Tritium Assessment
In the summer of 2015, members of the Enniskillen Environmental Association sampled three
water wells for analysis of the tritium content in the wells. The three samples provided
snapshots of the tritium content in the shallow subsurface, in the Mackinaw horizon (at about 20
m depth) and in the Thnorncliffe aquifer. Tritium presence in the first two are explainable as the
groundwater in these horizons have local recharge areas and represents recent water. The
presence of tritium in the deep well, although at a lower concentration than the others, indicates
post 1950's water, and there has been some debate as to its origin. The possibilities include:
1) Lateral subsurface flow from the Oak Ridges Moraine some 6 km to the north.
Independently calculated groundwater velocities support this possibility, however it is was
one point in distance and in time, and spatially offset samples are needed to assess this.
2) Poor well construction could cause a pathway from surface with the leakage of more tritium
concentrated water from above, mixing with the natural water at depth. An assessment of
the well casing and of other geochemical parameters to assess mixing are needed to assess
this.
3) Leakeage through discreet fractures in the dense Newmarket Till aquitard. Water quality in
the aquitard itself would be needed to assess this, and a calculation of the pathway
characteristics to see if it is plausible should be undertaken with this.
Based on the request from Council whereby Resolution #PD-079-15 was referred to staff to
provide a report n the estimated cost for a consultant's report regarding the source of
contamination and cost of tritium sampling/analysis, SLR has been asked to provide a cost
estimate to address the presence of tritium in the aquifer. (A separate cost for bacterial
assessment is provided under separate cover.) We propose a staged exercise to address the
most defineable items first which will in turn shed light on how to approach the more expensive
and less easily defined issues.
Prior to giving the reasoning and listing the tasks, we wish to ensure that the objective of this
work be clearly understood. If the objective is to identify if there is a linkage with the Hydro One
Transformer site, an analysis of tritium alone in the private wells may not be the way to assess
this. This is because the work done by Hydro One in response to Clarington's and MOECC
questions has established that there is little likelihood of a connection. This was reported by
SLR to Clarington in our report of late September, 2015 based on solid hydrogeologic and
physical evidence. Tritium was one minor line of evidence in that report that supported the
SLR Consulting(Canada)Ltd. 200-300 Town Centre Boulevard,Markham,ON DR 5Z6
T:905.415.7248 F:905.415.1019
www,slrconsulting.com
Attachment 5 to
Municipality of Clarington Report PSD-008-16
Municipality of Clarington Proposal No. 209.40542
Clarington North Tritium Study January 2016
interpretation of well safety from the Transformer Station. Point 1) above was deemed by SLR
to be the most likely possibility, although we did verbally recommend municipal support for the
requested tritium study at that time to close some of the other questions off. If on the other
hand, the objective is to provide insight as to well performance and to help assess the subtly
different conceptual hydrogeologic models proposed by SLR and Stantec, then the following
work is worthwhile.
Workplan
To reliably understand the tritium results to date, values must be reproducible and a spatial
pattern developed. The current three results are single points in time and geometry. We
propose first to do a "snapshot" of several strategically placed private wells in each aquifer
layer. Wells that are upgradient and wells that are downgradient in each layer should be
sampled and analysed. In the case of the Mackinaw and Thorncliffe aquifers there are many
private wells that qualify. The upgradient wells should be at least one half life away. At the
estimated flow rate of 100 m/year in the Thorncliffe this would be just over 1200 m to the north.
And downgradient it would be a similar distance. Some private wells not presently on the
program may have to be solicited to accomplish this. In fact all well owners will have to be
approached for their participation. We suggest doing this along three different north-south
transects to provide reproducible results. In the mackinaw the flow paths are shorter and locally
water travels at different rates and in different directions. In these cases wells upgradient of
Concession Road 7, along Concession Road 7 and downgradient of Concession Road 7
should be selected. Again three separate flow lines should be sampled. In the case of the
shallow dug wells, where the water source is at surface and near the well, six geographically
diverse wells should be selected, and it would be reasonable to assume that their measured
tritium values will be largely similar. This workplan does not include monitoring wells from the
site, as Hydro One has indicated they will not participate.
The above program is suggested as a starting point. It would be advisable to convene a
technical meeting of the parties (G360, CLOCA, Clarington, Hydro One, and MOECC) to refine
this design and ensure as reasonable a program is conducted from day one as possible. Once
the private well locations are selected and all are in agreement from a technical perspective of
what to expect, this sampling will then become the baseline from which to work. Once G360
has drilled their rotosonic boreholes and installed the multi-level monitors, further aquitard
sampling can be done (not costed here)for comparison and all parties can share data. We also
wish to point out that tritium is time sensitive, due to its half life. The logical future step would be
to resample this suite in 6 and 12 years to determine the rate of tritium concentration decay
which would provide insight into any mixing of water. (Future samples are not costed here.) It
would also be adviseable, as part of the baseline to capture and sample precipitation for tritium
analysis at the site to provide a realistic value for recharge water for at least the shallow wells.
Therefore a total of 19 samples plus two QA/QC samples (ond duplicate and one field blank),
totalling 21 samples have been budgeted for. The estimated cost' to do this first phase
would be $22,800 plus HST.
It is unknown if the four experts would charge to attend a scoping session, or would even agree to
attend. We have assumed four outside experts at a nominal$1000 a day retainer, that is, $4,000.
SLR 2
Attachment 5 to
Municipality of Clarington Report PSD-008-16
Municipality of Clarington Proposal No. 209.40542
Clarington North Tritium Study January 2016
Once the basline data has been collected and collated, the advisory group would reconvene.to
interpret the results and advise on supplementary testing. This second phase would include
integrity testing of deep wells (assume four for costing purposes)with abnormally high tritium
values, including geophysical logging, casing tests, video televiewer logs, and wellhead
inspections. Consideration on the need to include the helium testing discussed previously
would be given, however this has not been costed at this time. In addition, analytical scenarios
of leakage rates needed to influence water quality would be performed on agreed to wells. This
analytical assessment would also be applied to the more remote possibility of aquitard leakance
through undetected fracture networks, as postulated by G360. The cost2 to do this second
phase would be $26,000 plus HST. (This includes a budget for$10,000 for geophysical
testing.)
Once these steps have been completed, the advisory group should be reconvened to determine
if additional analytical scenarios would necessitate the use of a three dimensional groundwater
flow model, such as the one currently operated by CLOCA staff as part of the Oak Ridges
Moraine Coalition. Modelling is beyond the scope of this proposal. It is our understanding that
this model has the capability of running contaminant scenarios for a variable source such as
tritium. It should also be be able to assess longitudinal contaminant dispersion along any given
flow path. Confirmation of this would be sought from Dr. Gerber. The use of a groundwater
flow model allows one to explore differing scenarios, such as aquitard leakance, or the
coefficient of dispersivity, or the soil hydraulic conductivity. Once these aspects have been
considered, the results will be assembled in a comprehensive summary report. Review
comments will be collected from the advisory group and appended to the document, including
dissenting opinions. The cost2 to do this third phase would be $14,000 plus HST.
It is anticipated that this work could be completed in 6 months. The total cost will depend upon
participation by the various experts and their respective per diems and travel costs. We have
budgeted for 18 well samples, however this costs can be lower if the advisory group determines
a more streamlined program is possible, or they could be higher if more are technically
advisable. Therefore the total estimated cost of$62,800 is simply an estimate at this time to
provide the municipality some guidance of potential cost.
We trust this submission provides the information you were seeking.
Yours sincerely,
SLR Consulting (Canada) Ltd.
• I
Steven Usher
Project Manager
SJU/su
2 It is unknown if the four experts would charge to attend a scoping session, or would even agree to
attend. We have assumed four outside experts at a nominal $1000 a day retainer, that is, $4,000.
SLR 3