PRELIMINARY PUBLIC HEALTH ASSESSMENT
DUBLIN WATER SUPPLY
DUBLIN, BUCKS COUNTY, PENNSYLVANIA
DUBLIN WATER SUPPLY (DUBLIN TCE) SITE
SUGGESTED TIME FRAME TO IMPLEMENT ACTION TO PROTECT HEALTH
AND MONITOR TAP WATER FOR ALL USES
X = TCE Level in well.
(µg/L or ppb)
TO REDUCE EXPOSURE
|5 > X
5 < X < 50
50 < X < 130
130 < X < 260
260 < X < 2000
2000 < X
yr = year, mo = month, wk = week, immed = immediately, and TCE = trichloroethylene.
The above table presents a suggested time frame to implement protective measures in order to
protect public health from both chronic toxicity and an excess lifetime cancer risk (1 x 10-6) due
to multiple pathways (i.e., drinking, bathing, and showering). Note that the above table assumes
no previous exposure or other routes of exposure. The time-frame for implementing actions to protect public health and/or to monitor tap water would also be
dependent upon the length of previous exposure, current exposure, the status of the groundwater
contamination plume, or continued use of the groundwater resources for drinking, cooking,
bathing, or showering.
Dublin TCE Site Work Plan Developed by EPA in 1987 Consent Agreement
and Order - Page 1
In accordance with criteria established by EPA, point-of-use water treatment systems will be installed and periodic water sampling will be performed on selected private wells. The EPA established four categories, or tiers, to guide appropriate action for each well. Each tier addresses a TCE concentration range and appropriate corrective action and follow-up monitoring. The following outline describes each of the tiers. Tables 1 through 4 list the wells and observed TCE concentrations in Tiers 1 through IV respectively.
- - TCE concentration range: Greater than nondetected but less than 5 micrograms per liter (µg/L).
- - Corrective Action: None required.
- - Monitoring: Well water will be sampled twice annually.
- - TCE concentration range: 5 to 75 µg/L.
- - Corrective Action: At the discretion of the well user, either bottled water will be supplied or a
granular activated carbon (GAC) treatment system will be installed at the tap used for cooking
and drinking (kitchen tap).
- - Monitoring: Treated tap water will be sampled quarterly, and untreated well water will be
sampled twice annually.
- - TCE concentration range: 76 to 260 µg/L.
- - Corrective Action: A GAC treatment system designed to treat the entire water system will be
installed at all residential dwellings. At businesses, bottled water will be supplied, or a GAC
treatment system will be installed at the tap used for drinking water.
- - Monitoring: Treated tap water and untreated well water will be sampled quarterly. In the event
treatment systems are in place, samples will be conducted before and after treatment.
- - TCE concentrations range: Over 260 µg/L.
- - Corrective Action: Same as Tier III.
- - Monitoring: Treated tap water and untreated well water be sampled quarterly. In the event
treatment systems are in place, samples will be conducted before and after treatment.
The work plan includes a phased approach for the completion or implementation of all tasks outlined by the four tier system, as described below.
BCM will perform the following tasks prior to initiation of Phase II:
- - Determine the accessibility of each residence or business listed in Tables 1 through 4.
- - Obtain bids from contractors who can provide and install appropriate treatment systems within
a specified time table.
- - Determine the preference of each residence or business for bottled water or kitchen tap
- - Prepare a specific sampling schedule for treatment systems and wells.
- - Retain a contractor who will provide bottled water on a demand basis.
Phase II will include the provision of supplied water and installation of GAC treatment systems.
The following tasks are included in Phase II:
- - Implement a bottled water delivery program for those residences in Table 2 (Tier II) and
businesses in Tables 2, 3, and 4 who choose bottled water over kitchen tap treatment or drinking
water supply treatment systems.
- - Install a kitchen tap water treatment system at those residences in Table 2 (Tier II) and a
drinking water supply treatment system in businesses in Tables 2, 3, and 4 who choose treatment
over bottled water.
- - Install a full water treatment system at those residences listed in Tables 3 and 4.
- - Install a flow meter on all residences and businesses with treatment systems.
Phase III will consist of the monitoring program, maintenance of treatment systems, and provision of bottled water.
The following tasks are included in Phase III:
- - Conduct periodic sampling of treated water from those systems with GAC treatment and of
untreated well water in accordance with the schedules described above for each tier.
- - The first full set of samples (all wells before and after treatment) will be analyzed for volatile
organic compounds (VOCs) by gas chromatography (GC), using EPA Method 601. Thereafter,
samples will be analyzed for TCE, PCE, and vinyl chloride by Method 601, unless other VOCs
are detected in the first set of samples, in which case, such VOCs will also be analyzed.
- - Conduct a full round of sampling at the completion of Phase II.
- - Record flow rates concurrent with sampling each residence or business with a treatment system.
- - Periodic maintenance of GAC treatment systems will be performed in a manner consistent with
the system provided. This will normally consist of replacing the carbon bed.
- - Maintain the provision of bottled water, as appropriate.
- - BCM Quality Assurance/Quality Control (QA/QC) procedures will be followed in collecting
and analyzing all samples. QA/QC for monthly sampling will be covered during quarterly
The effectiveness of treatment systems will be evaluated after each sampling event. System repairs of maintenance will be performed whenever TCE concentrations are found greater than 5 µg/L in drinking water. The work plan shall remain in effect for at least 1 year after the effective date of the Consent Agreement. After 1 year, the sampling program will be evaluated, the sampling frequency and treatment system maintenance schedules may be adjusted and a new, modified work plan, approved by EPA, may be placed into effect.
Treatment and sampling will continue until it has been demonstrated to the satisfaction of EPA that TCE levels are consistently less than 5 µg/L. Such determinations will be made for each well on a case-by-case basis.
The implementation of the work plan will be triggered by the signing of the Consent Order.
|Task||Completion Time (Days)|
* Dependent on access to the individual properties
The following section was not available in electronic format for conversion to HTML at the time of preparation of this document. To obtain a hard copy of the document, please contact:
Agency for Toxic Substances and Disease Registry
Division of Health Assessment and Consultation
Attn: Chief, Program Evaluation, Records, and Information Services
1600 Clifton Road NE, Atlanta, Georgia 30333
RESPONSE TO PUBLIC COMMENTS
This document was released to the public for review and comment. Although the public
comment period ended April 5, 1991, some comments were received after that time. Those
comments and a response to the comments follow.
|COMMENT:||Water at the Whistlewood Apartments had TCE concentrations as high as
2,000 ppb, not a maximum of 500 ppb as reported.|
|RESPONSE:||PADOH contacted the EPA Remedial Project Manager for the site to
determine if data were available to indicate that the well water at
Whistlewood Apartments contained higher levels of TCE than previously
reported. No data are available to indicate that levels of TCE in water at
the Whistlewood Apartments were greater than reported.|
|COMMENT:||Whistlewood Apartments has 244 units, not 144 as reported.|
|RESPONSE:||The Whistlewood Apartment manager states that the complex contains 144
units, not 244.|
|COMMENT:||The installed charcoal treatment units for Tier I and Tier II did not treat
TCE-contaminated water for all uses, as reported. These units treated
kitchen tap only.|
|RESPONSE:||That is correct. The 1987 Consent Agreement stated that the owners of
water supplies that contained 5 to 75 µg/L TCE could choose to be supplied
bottled water or have a treatment system installed at the kitchen tap. Those
water supplies with less than 5 µg/L TCE were to be monitored twice a year,
and the owners were not supplied bottled water or a treatment system.
After consultation with ATSDR, EPA amended the consent agreement in
1991 to provide full-house treatment systems for all water supplies that
contain TCE above 5 µg/L.|
|COMMENT:||At a 1986 conference between the On-Scene Coordinator and ATSDR, it
was agreed that biological monitoring of the exposed population would be
conducted, but this was never implemented.|
|RESPONSE:||ATSDR agreed to inquire about the capability and usefulness of
biologically monitoring the exposed people. At that time, the Centers for
Disease Control and Prevention (CDC) had no methods to test TCE levels
in exposed people. Therefore, the study could not be conducted.
Currently, a test is available to measure VOCs, such as TCE, in blood
serum. However, that test is only for recent exposures. Some other tests
are now available that may indicate if damage has been done to certain
organ systems, such as the liver and renal systems, because of past
exposure. Tests such as those may be useful to the community.|
|COMMENT:||The  Thompson-EPA Consent Decree did not provide an adequate
level of treatment to the Tier II homes, which had levels of TCE up to 75
ppb and only received tap filters. This went on for over four years.|
|RESPONSE:||The 1987 Consent Agreement was modified on April 25, 1991, by EPA, in
consultation with ATSDR, to provide for full-house water treatment. Until
that time, either tap filters or bottled water were provided.|
|COMMENT:||The Roy F. Weston hydrogeologist opined in 1986 that, when the
Whistlewood Apartments opened in 1974, the water delivered to the 244
families contained over 500 ppb of TCE. Individual homeowners and
businesses surrounding 120 Mill Street were dosed with levels at or
exceeding this at an even earlier date. These exposures continued until 1986.|
|RESPONSE:||The contamination was not discovered until 1986. No data are available to
substantiate or dispute the hydrogeologist's opinion.|
|COMMENT:||ATSDR ignored one or more tests of installed, on-site monitoring wells, as
opposed to the two pre-existing plant wells. The levels of TCE in the
monitoring well directly downgradient from the rear of 120 Mill Street
plant was in excess of 15,000 ppb.|
|RESPONSE:||PADOH contacted EPA and inquired about this information. EPA does
not have any data to reflect that information. You are welcome to provide
any laboratory data that you have for our evaluation. Please include any
quality control/quality assurance information with the laboratory data.|
|COMMENT:||Dublin Borough officially requested ATSDR to include the residents of the
Borough in its national TCE Registry, but was turned down.|
|RESPONSE:||The TCE subregistry is closed at this time to new registrants. However,
the information on the health of people that are included on the registry
will, hopefully, provide important information in the future that can be
used by all people exposed to known levels of TCE. Some publications on
the information obtained to date are available through ATSDR's Division
of Health Studies. Additionally, if data indicate a need to expand the
registry or if new members are needed, Dublin residents will be considered
|COMMENT:||Tier II families bathed, showered and did their laundry in
TCE-contaminated water (up to 75 ppb) for over four years after EPA and
ATSDR knew of their predicament.|
|RESPONSE:||All of the actions, including descriptions of the two ATSDR health
consultations, taken at the site are described in this public health
assessment. Any specific questions about EPA's decisions should be
addressed to EPA.|
|COMMENT:||The statement...that "[A]ffected parties in Dublin are currently being
supplied treated water by the municipality to correct the problem" is
incorrect. The municipality does not have the funds to take any actions to
remediate the release of hazardous substances from 120 Mill Street.
Although the Borough has not done so, it will install public water to the
affected homes, if provided funds from the PRPs or EPA.|
|RESPONSE:||The correction has been made in this document.|
|COMMENT:||..., ATSDR states that: "[S]pecifically, if data or information indicate that
exposure to TCE through the domestic use of groundwater is currently
occurring, then this site will be evaluated." TCE exposure through use of
domestic water wells is occurring. See [previous] comment.|
|RESPONSE:||Some clarifications have been made in this document to better reflect what
information is needed for further evaluation.|
|COMMENT:||The Borough reiterates its call to ATSDR to undertake medical and
biological monitoring of the residents, along with an epidemiological study
of those persons exposed to TCE.|
|RESPONSE:||Your request will be given to ATSDR's Division of Health Studies for consideration. The Division will determine if a health study would benefit the community. If ATSDR determines that the community would benefit from a health study, one will be considered as resources become available.|