Proposal - Rehab LW-31 Evaluation High Chlorides

Headquarters
19505 NW 184th Terrace
High Springs, FL 32643
South Florida Office
26 NW 12th Street
Delray Beach, FL 33444
Office: 386.462.0781
Fax: 386.462.0059
Cell: 561.479-8031
Email: [email protected]
_____________________________________________________________________________
Water Resource Consultants
November 30, 2015
Fred Greiner
Palm Coast WTP 2
2 Citation Drive
Palm Coast, FL
Re: Proposal – City of Palm Coast – LW-31-Evaluation-Revised
List of Figures
1. Well Location Map
2. Well Site- LW 31
3. Pump Base & Well Head
4. Pump Bowls
5. Well Head Photo
List of Tables
1. South Well Field-Existing and Proposed Wells
2. LW 31 Well Construction Details
3. Before and After Well Performance
4. Comparison of South Well Field Performance
Dear Fred:
Connect Consulting, Inc. (CCI) is pleased to submit our proposal to conduct an evaluation
and develop a remedy to address increases in Conductivity/Chlorides at Public Water
Supply Well LW 31. LW 31 is an Upper Floridan aquifer (UFA) well, constructed in 1990
and serves Water Treatment Plant (WTP) No. 2 (see Figures 1-5). Towards that end, we
have developed a primary scope of work with alternates to complete the project as
requested by the City.
Discussion
LW 31 was constructed in early 1990 as part of the first South Well Field expansion, which
also included the construction of wells LW 21, LW 23, LW 30 and LW 32. Wells LW 14,
LW 17 and LW 49 had been constructed in the mid/late 1970s. LW 17 is now plugged and
abandoned. Wells LW 17R (a replacement well for LW 17), LW 105, LW 107 and LW 108
Page 1 of 5
are currently under construction. LW 84 and LW 106 were constructed in 2009 as part of
an Aquifer Performance Test (APT). LW 22, LW 83 and LW 85 are future, proposed wells
(see Table-1)
Table 1- South Well Field-Existing and Proposed Wells
No.
Well1
No.
Year
Constructed2
Current
Status
DID2
1
2
3
LW 14
LW 17
LW 17R
1973
1979/2015
2015
4
5
6
7
8
9
10
11
12
13
14
15
LW 19
LW 21
LW 22
LW 23
LW 30
LW 31
LW 32
LW 49
LW 83
LW 84
LW 85
LW 105
2009
1990
TBD
1990/2006
1990/2007
1990
1990/2013
1977/2004
TBD
2009
TBD
2015
16
17
LW 106
LW 107
2009
2015
18
LW 108
2015
In service
Abandoned
Under
Construction
In service
In service
Proposed
In service
In service
In service
In service
In service
Proposed
Constructed
Proposed
Under
construction
Constructed
Under
construction
Under
construction
Notes:
1.
2.
3.
4.
Casing3
Depth
(ft.)
105
101
101
Total3
Depth
(ft.)
300
215
150
Rate4
(GPM)
6673
6623
TBD5
Casing3
Dia.
(in)
8
12/8
12
6648
6649
6650
35373
6639
6640
6641
6674
39255
39256
39257
438762
12
12
12
12/8
12
12
12
14/10
12
12
12
12
116
109
110
102/116
108
105
101
98/110
110
115
110
110
230
335
250
250
120
320
258
225/310
150
135
150
150
165
358
189
300
80
200
130
260
145
145
145
145
438763
438764
12
12
105
110
130
150
145
125
438762
12
110
150
125
80
145
145
Year constructed or re-constructed as LW 32 or modified as LW 14, LW 17, LW 23, LW 30 and LW 49 or for
proposed wells LW 105, LW 107 and LW 108, or if unknown then TBD-To Be Determined.
Casing diameter, casing depth and total depth are indicated as Original/Modified e.g. LW 17 was originally
constructed with 12-inch casing but will be modified with an 8-inch liner, shown as 12/8.
SJRWMD modeled pumping rates.
TBD-To Be Determined
The purpose of this project is to provide for the furnishing of all labor, equipment, and
performing all operations for the evaluation of one (1) Public Water Supply (PWS) well
(LW-31) for the City of Palm Coast , Palm Coast, Flagler County, Florida, referred to as
the Primary scope of work. Also, we have included three (3) alternates for your
consideration at this time. Table 2 lists the well construction details for LW 31.
Table 2 – LW-31 Well Construction Details
Notes:
Casing
Material
Casing
Depth
(Feet)
Open Hole
Diameter
(Inches)
Total
Depth1
(Feet)
Rated
Yield
(GPM)
Current
Yield
(GPM)
12-inch
PVC
105
11
320
833
700
Depths are from land surface.
Depths are approximate and based on existing well construction details.
In 2013, LW 31 was acidized(1,000 gallons of 200 Baume hydrochloric acid(HCL)) and
rehabilitated. Before and after rehabilitation, the well performance was as listed in Table
3 below:
Page 2 of 5
Table 3- Before and After Well Performance
Status
Test
Date
Before
After
New
8/6/2013
9/4/2013
3/23/1990
Static
Water
Level
(ft.)
15.50
16.10
9.60
Pumped
Water
Level
(ft.)
19.24
18.00
19.60
Drawdown
(ft.)
Pumping
Rate
(GPM)
Specific
Capacity
(GPM/ft.)
Improvement
(%)
3.74
1.90
10.00
600
600
1,200
160
316
120
98
-
Also shown in Table 3 are the results of the final pumping test conducted when the well
was new, constructed and tested in 1990. Note the regional decline in the static water
level recorded in 1990 at 9.60 feet below top of casing versus 16.10 feet today. Water
levels in the region have declined approximately 10 feet over that +20 year period.
Table 4 lists LW 31 performance after rehabilitation as compared to the other UFA South
Well Field wells which are currently in service. LW 31 specific capacity of 316 GPM/ft.
ranks as the highest for all eight UFA wells, average being ~126 GPM/ft. However, water
quality, as indicated by Chloride concentration for LW 31 measured at 195 mg/l in August
2013 ranks higher than the average value for all UFA wells, that average being 131 mg/l.
Table 4- Comparison of South Well Field Performance
Well
No.
Test
Date
LW 14
LW 19
LW 21
LW 23
LW 30
LW 31
LW 32
LW 49
8/7/2013
8/1/2013
8/1/2013
8/1/2013
8/6/2013
9/4/2013
8/7/2013
8/6/2013
Static
Water
Level
(ft.)
18.46
20.39
17.80
16.02
14.08
16.10
21.90
19.54
Pumped
Water
Level
(ft.)
28.75
30.10
22.36
26.35
17.63
18.00
24.50
38.27
Drawdown
(ft.)
Rate
(GPM)
Specific
Cap.
(GPM/ft.)
Chlorides
(mg/l)
10.29
9.71
4.56
10.33
3.55
1.90
2.60
18.73
510
360
650
890
660
600
390
470
50
37
45
86
186
316
150
25
200
30
45
105
250
195
190
35
Scope of Work
Primary
A. Hydrogeologic Services:
1. Project management
2. Data collection & interpretation
3. Oversight
4. Reporting
B. Well Field Services
1. Mobilize all equipment necessary to successfully complete the work as
specified.
Page 3 of 5
2. Remove and inspect the pump, a 40 HP submersible pump set on 80 feet of
8-inch Certalok column, in the field. Report any pump issues to the City, store
the pump on site (note: since the Afton, 4-stage pump was refurbished in 2013,
we don’t expect there to be any pump issues).
3. Install a test pump capable of producing up to 800 gallons per minute (GPM).
4. Remove/re-set the test pump from the well as needed.
5. Conduct static and pumped geophysical logs/TV survey on the well.
Geophysical logging/TV services are to be provided by a pre-approved logging
service provider, as follows:
a. Static caliper
b. Static electric (Resistance & Self Potential)
c. Static natural gamma ray
d. Static fluid temperature
e. Static fluid resistivity
f. Static fluid velocity
g. Pumped fluid temperature
h. Pumped fluid resistivity
i. Pumped fluid velocity
j. Static and pumped TV survey
6. Raise well head and discharge piping to comply with current Florida
Department of Environmental Protection (FDEP) regulations.
7. Re-install the pump and re-grout the base.
8. Disinfect the well.
9. Flow test the pump.
10. Clean-up and restore the site.
11. Demobilize all equipment and secure site.
Alternate No. 1- Conduct Packer Test
1. Hydrogeologic services.
2. Install an inflatable packer at ~150 feet inside the open hole section of the well.
3. Conduct a short duration pumping test.
Alternate No. 2
1. Hydrogeologic services.
2. Permit and back plug the well
Alternate No. 3
1. Hydrogeologic services.
2. Conduct post back plugging static and pumped geophysical logs/TV survey.
Note: Alternate No. 1 consists of conducting a packer test to isolate the lower water
producing zone from the upper water producing in order to quantify more accurately the
contribution that the lower zone has to water quality degradation and the subsequent loss
of well yield if that zone is eliminated by back plugging. It is highly likely that LW 31 will
need to be back plugged to maintain water quality, similar to recently modified/back
plugged Well LW 14 located just 2,000 feet north of LW 31, requiring the need for Alternate
No. 2. Once the well is modified by back plugging, LW 31 will perform quite differently.
Alternate No. 3 is intended to document those changes before the well is put back into
service.
Page 4 of 5
Cost
We propose to team with Freeman Well Drillers, Inc. and will complete this project as a
lump sum fee as follows:
Primary- Provide hydrogeologic & well field services to evaluate LW 31
Time of completion
$27,500
70 Days
Alternate No. 1-Packer Test
Time of completion
$8,000
20 Days
Alternate No. 2- Permit & Back Plug Well
Time of completion
$8,000
20 Days
Alternate No. 3- Post back plug geophysical logs/TV survey
Time of completion
$8,500
10 Days
We can begin within 3-weeks after receipt of a P.O. Field work will be started on the
Primary scope of work immediately.
Let me know if this is acceptable.
Sincerely:
Gary E. Eichler
Gary E. Eichler, P.G.
Hydrogeologist
Connect Consulting, Inc.
Cc:
Richard Adams
Jim Hogan
Page 5 of 5
Figures
LW 31
Figure 1- Well Location Map
Figure 2- Well Site- LW 31
Figure 3- Pump Base & Well Head
Figure 4- Pump Bowls
Figure 5- Well Head Photo