WELLHEAD PROTECTION PROGRAM
Borough of Grove City, Pennsylvania
July 1993
Submitted To:
U.S. Environmental Protection Agency
Region 3
Prepared By:
HORSLEY & WTTTEN, INC.
ENVIRONMENTAL SERVICES
WASHINGTON, DC BARNSTABLE, MA
-------
-------
TABLE OF CONTENTS j
i
i
Page
Introduction ! i
Purpose I i
i
Step #1 - Identify Duties and Responsibilities 1
Step #2 - Delineation of Wellhead Protection Areas 2
i
Step #3 - Identification of Potential Contamination Sources 6
Step #4 - Management Tools ; 8
Step #5 - Public Education i 14
LIST OF TABLES
Table
1. Summary of Wellhead Protection Tools
LIST OF FIGURES
Figure
Wellhead Protection Areas
-------
-------
member of the Utility Committee and the Borough Manager attended a
workshop in Grove City, sponsored by EPA Region 3 on 5 May 1993. Also
present were representatives of the Pennsylvania Rural Water Association
and the Pennsylvania Department of Environmental Regulation and the
EPA. All of these organizations will play key roles in the development and
implementation of a wellhead protection program for Grove City.
i
i
The Grove City Borough should set up a wellhead protection! committee
made up of local officials (including water department, planning board, and
the Borough Manager), a representative of Pennsylvania DER, and a
representative of the Pennsylvania Rural Water Association. Specific duties
of each member should be defined by local officials. The Grove City Borough
Water Department is responsible for delivering potable water to consumers
and it may be the most appropriate lead agency for the wellhead protection
program. Technical assistance is available from Pennsylvania Rural Water
Association, Pennsylvania Department of Environmental Regulation and the
U.S. Environmental Protection Agency. !
i
Step #2 - Delineation of Wellhead Protection Areas
The Borough of Grove City is dependent upon ground water as its source of
drinking water. Three wells (#1,2 and 3), located in the downtown area, were
abandoned due to trichloroethylene (TCE) contamination. Foiir new wells
(#4, 5, 6 and Memorial Park) currently serve 8,162 Grove City eind 890 Pine
Township residents. These four wells have a rated maximum! pumping
capacity of 2.6 million gallons per day (MGD), and an average pumping rate of
1.2 MGD (or 46% of capacity). i
j
|
Wells #4, #5, and #6 are approximately 350 feet deep and tap the Upper and
Lower Connoquenessing Sandstone Aquifer which is confined between layers
of low-permeability shale. A great deal of hydrologic information can be
obtained from the pumping tests of the Grove City wells, the tests
immediately preceded most of the constant pumping rate tests with step tests
without sufficient recovery before beginning the constant rate long-term tests.
Grove City WHP Program -2- Horsley & Witten, Inc.
27 July 1993 |
-------
GROVE CITY
WELLHEAD PROTECTION PROGRAM
Introduction
The wellhead protection (WHP) program was established in 1986 after
amendments to the Safe Drinking Water Act (SDWA). The WHP program
was designed for, and has been extremely successful in, protecting ground
water which supplies wells and wellfields that contribute drinking water to
public water supply systems. Wellhead protection requires the participation
of all levels of government. The foremost responsibility for ensuring that
ground water is adequately protected lies at the local government level.
Purpose
Because of their interest in promoting wellhead protection iri local
communities, Region 3 of the Environmental Protection Agency (EPA)
funded a project to provide wellhead protection in two Pennsylvania
communities, one of which is Grove City. The purpose of this project was to
provide "hands on" training for applying EPA's Wellhead Protection
Program. This report summarizes our analysis of background materials, a site
visit, and a public meeting coordinated in Grove City, Pennsylvania. It is
structured according to the five steps for wellhead protection outlined in the
Safe Drinking Water Act Amendments of 1986. The report was prepared by
Horsley & Witten, Inc. (H&W) under contract to the EPA Region 3 office in
Philadelphia, Pennsylvania. The project was also coordinated with the
Pennsylvania Rural Water Association and the Pennsylvania Department of
Environmental Resources.
Step #1 - Identify Duties and Responsibilities
The primary contact for coordination of the wellhead protection program has
been the Borough of Grove City. Three members of the Borough Council, a
Grove City WHP Program -1- Horsley & Witten, Inc.
27 July 1993
-------
-------
.
T -aSM
".C^ '';- s| :sg|| '.
- $! '' '
.'. -. \ r
",-, - . o
. -^ . LB ./
.
f? ~ ' "' "
Aquifer and
Wellhead Protection Areas
Grove City, PA
Aquifer Protection Areas
Burgoon Sandstone Outcrop
Connoquesnessing Formation Outcrop
Wellhead Protection Areas
| | WHPA
North
1000 0 2000 3000
scale (feet) H&W,
-r .' , . ! :...--
«-.. i f ". A i ' . ;
. - .."/ v-«*, :) '.
" ^.- r Sx"1 - \'>. ,- I'"" ,
\ A ,% '.vV ., -//- I;
'
4rfN
-------
1
Analyses for aquifer properties are not possible from these data effected by the
step tests. The data also could not be analyzed with the Jacobs equations for
distance-drawdown because the more distant observation well (#6 at 900 feet)
had a greater drawdown that a closer observation well (#4 at 800 feet). This
deviation from expected conditions indicates that the aquifer transmissivity
and/or storativity are not homogeneously distributed throughout the aquifer.
However, analysis of one test, that of pumping well #6 while observing water
levels in well #4, which was not effected by a step test, yields a transmissivity
of 55,000 gpd/ft. and an artesian (confined conditions) storativity of 0.0001.
Radii of influence calculated with these confined aquifer values would be
exceedingly large (about 5 miles after 2 days!). Possible reasons could be that
the town overlays deep coal mines and this well could be inducing flow from
Wolfe Creek. I
i
i
All of the semilog plots of drawdown versus time showed boundary
conditions were encountered during the tests. Pumping well #4 at 310 gpm
showed the development of steady state conditions in which recharge equals
discharge after about 14 hours of pumping (no increase of drawdown from
800 to 2,880 minutes). This indicates a nearby recharging boundary
contributing 310 gpm. Definite decreases in anticipated drawdown (deviation
from the straight line plot) for observations in wells #4, #5 and #6 are shown
at about 600, 600, and 560 minutes respectively while pumping well #5. The
significance of the times of encounter for these boundaries isi uncertain
because of the complications created by the effects of the step test, but all three
of these deviations represent the presence of a recharging boionclary near the
three wells and, perhaps, somewhat closer to well #6, the most westerly of the
three wells. Indeed, well #6 is closer to Wolf Creek. Well #6 is located
between the pumping well and where Wolf Creek crosses th«> outcrop areas of
the sandstone aquifer. It is concluded that where Wolf Creek crosses the
aquifer outcrop area, a significant recharge to the aquifer occurs under
pumping conditions. j
I
In addition, observations in well #4 during test pumping of well #6 shows
the effect of a recharge boundary at about 1,440 minutes, whi<;h strongly
Grove City WHP Program -4- Hprsley & Witten, Inc.
27 July 1993 i
-------
suggests that the recharging boundary is on the opposite side of well #6 from
well #4. This test of well #6 also showed some deviations toward increasing
drawdown at earlier times during this test. These could represent low
permeability boundaries or, more likely, other wells pumping in the vicinity.
The 48-hour test of the Memorial Park well, to the west of Wolf Creek, does
not reveal any boundary conditions, either because they are too close or too
far away. There is no tendency toward stabilization during the 48-hour test
on this well. The Burgoon Aquifer, which is tapped by this well, is
stratigraphically below and separated by a confining shale bed from the Upper
and Lower Connoquenessing Sandstone aquifer tapped by wells #4, #5, and
#6, and does not outcrop nearby at Wolf Creek, but outcrops farther to the
north of Grove City. Although the engineering report determined a
transmissivity of 61,600 gpd/ft. for the aquifer here, observations from the
pumping well cannot be analyzed for storage coefficient, except to say that it is
small as typical with confined conditions.
Three methods were applied to delineate wellhead protection areas for the
Grove City wells. Aquifer recharge areas were mapped utilizing United States
Geological Survey and Pennsylvania Geologic Survey bedrock geology maps
of the area (reference). Recharge areas were mapped where the producing
unit (Connoquenessing for wells 4, 5 & 6 and Burgoon for Memorial Park)
were mapped as an outcrop (appearing at the land's surface and therefore
susceptible to contamination sources).
A semi-analytic model developed by U.S. Environmental Protection Agency
(EPA) known as the WHPA Code (MWCAP Module) was utilized to map the
area which contributes to the #4, 5 & 6 wells. This method was selected
because sufficient data was available and it incorporates ground water flow
direction. Aquifer properties (hydraulic conductivity and aquifer thickness)
were determined from the pump test data and boring logs as discussed above.
Ground water flow direction was assumed to be northwesterly toward Wolfe
Creek as indicated in the mapping of piezometric surfaces at the Osborne
landfill. A hydraulic gradient of 0.0036 was utilized based upon piezometric
Grove CityWHP Program -5- ' Horsley & Witten, Inc.
27 July 1993
-------
measurements in the Connoquenessing Formation at the Osborne landfill
site. Wolfe Creek was modeled as a stream boundary recharge zone because
the Connoquenessing Formation has been mapped to coincide with the
stream. Five-, ten-, and fifteen-years time of travel was selected for use in the
model. Two pumping rates (average and maximum rated) were modeled.
]
A calculated fixed radius method was employed to determine the WHPA for
the Memorial Park well. This method calculates that portion of the aquifer
which contributes water to the pumping well over a specified time period (10
years was modeled). In this case, because no information about ground water
flow was available, a flat water table was assumed with ground water flowing
into the pumping well radially from all directions.
The mapping of both aquifer and wellhead protection areas for the Grove City
wells is appropriate due to their unique hydrogeologic setting. All of the
wells draw water from aquifers which are overlain by low permeability strata
(shale) resulting in a semi-confined condition. For this reason the outcrop
areas were mapped showing were water enters these aquifers. However, the
confining shale layers are likely to be fractured allowing the pumping wells to
draw ground water downward from overlying aquifers and ultimately from
the overlying land's surface. The WHPAs show those land areas where water
may be induced downward through the semi-permeable shale layers and into
the producing aquifer. j
Step #3 - Identification of Potential Contamination Sources
i
Potential sources of contamination within the delineated wellhead protection
areas to the two existing wells and the proposed well were determined from
USGS topographic maps and from information supplied by the Grove City
Municipal Waterworks. The delineated WHPAs contain two sites where
ground water contaminants have been reported in the past. First, the
Osborne Landfill site is located to the southeast of the wellfield and at the 15
year time of travel boundary when the wells are pumping at maximum
capacity. Two considerations make this source unlikely to actually impact the
Grove City WHP Program -6- Horsley & Witten, Inc.
27 July 1993
-------
wells: a) the wells have never been pumped at this rate for extended periods
of time, and b) ground water contamination at the site is reported to be
limited to the upper aquifer and not in the deeper Connoquesnessing and
Burgoon formations where Grove City's wells are screened.
The second potential source is the industries which reportedly caused the
contamination of wells 1, 2 and 3 located to the south of the current wellfield
(4, 5 and 6). The WHPA delineation shows that these industries are located to
the south of the wellfield. The delineations suggest that the industries would
not impact the wells at lower pumping rates (whereby the WHPA does not
extend as far southwesterly). Furthermore, even if contaminants from this
site enter the WHPA, sufficient dilution may occur between the
contamination source and the wellfield to prevent concentrations in excess of
drinking water standards.
The numerous coal mines (commonly 40 feet in depth) throughout the
delineated WHPAs are a potential source of contamination which were noted
during the 5 May workshop . These mine shafts may serve as direct conduits
from the land surface to the producing aquifers making the ground water
more vulnerable to surface-derived contamination sources such as road
runoff and accidental spills. These mine sites should be inventoried and
evaluated as potential sources (or conduits) of contamination.
Numerous small businesses along Main Street and South Madison Avenue
may utilize hazardous materials and may generate hazardous wastes. While
the quantities may be small, they may represent a serious threat to the ground
water quality. A door-to-door inventory of these land uses may be the most
effective method of evaluating these potential sources. An example of a
successful volunteer inventory of this type is the City of El Paso, Texas who
utilized retired senior citizens to complete such an inventory. This case study
is documented in guidance materials available from USEPA.
The modelling of the wellfield shows that a significant .amount of water is
likely to be induced from Wolfe Creek under pumping conditions. This
Grove City WHP Program -7- Horsley & Witten, Inc.
27July 1993
-------
y
being the case, additional potential sources upstream must be considered in
the wellhead protection program. Extensive farmlands and ^Interstate 84
represent potential contamination threats in these areas. Farmlands may
generate pesticides and fertilizer runoff which could find its way into Wolfe
Creek and be induced by the pumping wells. Stormwater drainage from
Interstate 84 may contain metals, oils, greases and de-icing chemicals.
I
i
Step #4 - Management Tools j
Management approaches to wellhead protection can include both regulatory
and non-regulatory measures. Regulatory resources include zoning,
subdivision, and health ordinances. The Pennsylvania State; Enabling
Legislation provides extensive authority to local governments to protect
water resources. Non-regulatory measures include monitoring and public
education. Table 1 provides a summary of potential wellhead protection
measures. ;
i
i
Several non-regulatory tools may be appropriate in beginning Grove City's
wellhead protection program. Several of the potential contamination sources
identified in the preceding section of this report could be further evaluated
(and possibly managed) with non-regulatory techniques such, as public
education and monitoring. It will be important to educate business owners
within the delineated WHPAs who utilize hazardous materials that even
small quantities of these materials must be handled carefully. Monitoring of
water quality at the abandoned wellfield (1,2 and 3) may be important in
evaluating the potential movement of contaminants toward the new
wellfield. Similarly, monitoring at the Osborne landfill site should be
coordinated with Grove City's wellhead protection efforts. Horsley & Witten,
Inc. has made the initial contact with EPA's Superfund site manager for this
facility. Additional contacts should be made by the municipality to encourage
the sharing of information. \
Grove City WHP Program -8- Horsley & Witten, Inc.
27 July 1993 !
-------
.2
2
w
a
ra :s 3
£
a
O
°
I
TJ 3
2 C CO
22 =
S=60I
01 X
4) C «
»!H
00
c
i
o
a
c
a>
n
S g 8
.»- a ."^
i §
3 .5
a: o
f S
° '5i
^§
J|<
?H
-~-f
a ^ w
ll>
O! > .5
p > 3 § 5
S S eo S E
S 1 * £ .= S
§ 11 g II
fi 1 f 11
S .^ ei cj Q i
C£ O Su^ Cu.5
60
C
§
a
e
O»
flj cj
s
Grove City WHP Program
27 July 1993
-9-
Horsley & Witten, Inc.
-------
s
12 § 12
tJ5l 3tS E 3
mi^
i>|il|
U t3 O U "u S
n XI
= 03 S .50"
S-1 S lags
||1I1I2^
s E
S a s
E c S
Hi
in u.
§ *O ."
= i§S
o "3 "^ ~
oo So cj =^
c ?r as
* w <3 _
a-5.5 J
« 5 5 -
a.Sj-5-g
S8 |
&S a '«
§2 a 3
c3 32 =
o
T3
'«
I
" .= 1 i ^
£ ? « .2P~
5 S> "5. "2. e
1H iff
2 -S r 2 |
11-5 I §1
i
s
I
» S-
g. I
O 01
«
Grove City WHP Program
27 July 1993
-10-
Horsley & Witten, Inc.
-------
I
5
m
1
c ra 60 «
.2 i: c «
1:111
I'll
C-
-II
S 2
g «
-E Si
.
o 3 S
-o "
o S i s
K c
ll
§*§
I
i
o
o
I
JU
H.
§ o:
o oo
II
O jn
i .2
jj S
II
Grove City WHP Program
27 July 1993
-11-
Horsley & Witten, Inc.
-------
g
.a
.s
s
a
Z
S
I
a
J
el
g.2
S 8
II
11
1*
§!§! s
*ll« I
IH* 1
2 S « o 9-
S-3 ^> - §
§ 8-5? | .
w * S s M
&2 I t §.5
S S 2 S .38
IjiH?*
Hil
.
-2 B.-
till
«o
§ 8 §
O, S «
S g
3 O
f S
3 | 1 §
IIS
* w o
a. S
^§
JJPS
ft
g
i.
i
|
"S
o
1
Of
g
Grove City WHP Program
27 July 1993
-12-
Horsley & Witten, Inc.
-------
c
o
S
c
E
a
n
I
C
JF
tl!
Ill
ill
01
SB eotJ
2 = 2
3 c ra
f sg-
*
c
o
||
i i s 11 < a
E 60 .5 .2 <= .5
5S
2 ~
a 2
tsiSs
S >N.2 £ 3 S-i 3 S
3 h eo ra 5- O. c S->-
< S 2iS £3 8 8 2L
II
O 3
u a
II
'EblE
3 a
II
60-C
'w g .5*
a £g
-g. S 'S
Ss«8
III
(3 eft *.S
Sis =
Hi
« s-
.2.JS n
5 ~ tn
W 3 " O
11 HI
ItJif
8 x E ||g
3* S- O §i £ G
*75 ** ^o o * ***"*
1 1 I f -i f
a e Q-
!a a >, o a
js -° 60 x =
Ultfl
It! Ill
tl
1
"I
= 5^0-
lill
!i.
II'
*H«
1 c5^ §
till
i
o
o
ffl
> >
1 1
m o
? 1
g5
' «2
T3
J
Grove City WHP Program
27 July 1993
-13-
Horsley & Witten, Inc.
-------
Watershed protection efforts for the Wolfe Creek may also play a key role in
Grove City's wellhead protection program. Stormwater management
activities related to Interstate 84 by the Pennsylvania Department of Public
Works should be coordinated with the objective of water quctlity protection of
Wolfe Creek. Best management practices should be encouraged by the
farmers within this watershed (upgradient of Grove City).
Step #5 - Public Education
A public meeting was held on 5 May 1993, in the Borough of
Grove City. This
preliminary wellhead protection plan was presented and discussed.
Approximately twelve citizens and local officials attended. Future public
meetings and workshops are recommended to ensure implementation of the
wellhead protection plan. To ensure full development implementation of
Grove City's wellhead protection program, a Committee should be
formulated. The Committee should meet at least quarterly and preferably
monthly (to ensure better continuity). Regular agenda items to be discussed
could include water quality monitoring data, progress at the Qsborne landfill
site, well pumping information, review of proposed development projects,
and public education efforts. j .
i
The posting of "Wellhead Protection Area" signs would serve as an effective
public education tool. Such signage would alert truck drivers carrying
hazardous cargo that they are entering a sensitive environmental resource
area. They would also serve to remind citizens that they live on top of their
drinking water supply and therefore need to take preventative actions to
protect it. i
Grove City WHP Program -14- Horsley & Witten, Inc.
27 July 1993
-------
------- |