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Report Summary
Introduction.
Authorization
Pursuant to the contract agreement between MTC, Inc. (MTC) and Eagle
Water Company, Inc. (EWC or "the Company ), MTC, Inc. has performed this
water distribution system study on the Company s system.
Purpose, Need, and Plan of Study
The purpose of the investigation wc:s 1) to identify current system
pressure and supply deficiencies, if any; 2) to identify and analyze potential
remedial actions; and 3) to generate a model for the Company to use as a tool in
current and future planning, monitoring, and management. The scope of the
investigation was system-wide. At the current time, the Idaho Department of
Environmental Quality (IDEQ) has placed a development moratorium on the
Company certified service area until system pressure deficiencies are
identified, quantified, and a remediation plan is approved and financed.
The principle need for the study was to identify facility improvements, if
any, needed to eliminate low pressures.
The need for additional supply has long been recognized by Eagle Water
Company due to continued growth in the area. In the early 1990's, a well was
proposed near State Highway 55 (SH-55) and Hill Road, however, access was a
major obstacle and the well was never drilled. Well #4 was completed in 1992
near the South-central area of the service area. Well #61 was completed in 1996
near the West end of the service area. The plan is to connect to the existing
Floating Feather mainline to create a system loop and maximize the use of Well
#6. To date this plan has been thwarted due to the allocation of the requisite
service area of United Water-Idaho.
In the mean time, the City of Eagle has been in a significant growth
pattern. Census and population estimates, as obtained from the Idaho State
Department of Commerce and Labor and other sources, are shown below:
I There is no Well #5.
1990 577
1995 777
2000 085
2004 16,176
The 2006 population estimate by the City of Eagle is 20,130.
The demographics group of COMPASS of IDAHO, the regional planning agency,
provided the following population figures:
2005 19, 124
2010 227
2015 25,854
2020 28,216
2025 29,785
2030 31 ,043
(See chart on next page.) Portions of this growth were by annexation and were
outside the Company s service area. However, growth has occurred within the
EWC service area as well through population growth, residential infilling, and
an expanding commercial base as shown by the increase in the number of
residential and commercial accounts serviced. From 2002 to 2004 well
production increased about 23 percent. The need for additional supply remains
to this day.
Eagle Water Company wants an updated master plan to keep pace wit.h
the growth in its service area and to continue to provide cost-effective, quality
service to its customers. Such a plan will help the Company stay ahead of the
curve and anticipate domestic water supply needs and fire flow requirements.
The plan of study was to utilized a computer-based modeling software,
calibrate the model to available existing system data, and then test various
scenarios in the model to see their impact on the overall system s modeled
operation. Following the evaluation, prioritization, and recommendations.. of
various alternatives, a funding methodology will be recommended and an
implementation schedule proposed based on the availability of funding.
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2
Generalized Description of the Existing Conditions and Water System
The certified service area of Eagle Water Company, Inc. lies in portions of
Sections 2, 3, 4, 8, 9, 10, 11 , 14, 15, and 16, in T. 4N., R. IE., B., City of
Eagle, Ada County, Idaho. Physiographic ally it is on the alluvial fan of Dry
Creek together with portions of the adjacent Boise Front foothills and the Boise
River floodplain, all North of the North Channel of the Boise River between River
Miles -42 and -46. Portions in the North and East lie on terraced alluvium left
by the down cutting of the Boise River. Topographically the majority of the
service area lies West of the Boise Front foothills between elevations 2650' and
2500 feet; the balance rises to the East to an elevation of 2800::t feet. The
geology, as read in the well logs , is generally coarse sand to silts and clays, with
minor horizons of coarser grained materials from major storm events, as would
be expected at the mouth of a major drainage. The soils in the alluvial fan areas
are in the Notus-Moulton-Falk series while those on the foothills are in the
Quincy-Lankbush-Brent series.2 With the exception of Dry Creek, the surface
hydrology has been significantly modified by over a century of agricultural
activity and by urbani suburban development. Groundwater is encountered
between -2' and -40' depending on proximity to the river; well depths vary from
230' to 466 feet; and drawdown varies from 60' to 130 feet.
There are no known cultural resources, prime agricultural lands, or
wetlands in the service area. The Southern boundary of the service area is the
North Channel of the Boise River that is in the City of Eagle s designated Scenic
Corridor. Most of the area is developed and in general. the native fauna and
flora have been supplanted by domestic pets, decorative plantings and grasses.
One well is located planimetric ally in the mapped fringe area of the Boise
River floodplain; however, it is elevated above the 100-year base flood elevation
as required by the City ordinance.
With an estimated 2006 population of 20,130, the City of Eagle covers
about 17 square miles. The Company s water distribution system lies generally
within the City of Eagle and it's area of impact. Service is provided to 2936
residential accounts, 178 commercial accounts, and 112 landscaping accounts.
2 Soil Survey of Ada County, Idaho; USDA Soil Conservation Service, 1977.
The supply and distribution systems, owned and operated by the
Company are the subject of this study. Included are five wells (# 1, #2, #4, #6,
and #7) arid associated pumping stations, one reservoir, one booster pump
station, and approximately 54 miles of waterline, with appurtenances, of which
about one mile (less than 2% of the overall system) is smaller than 6-inch. All
these smaller lines serve five or fewer customers and/or short cul-de-sacs, and
all are without fire hydrants. These are acceptable. See Appendix One for
details.
The existing water supply is pumped groundwater from the deep aquifers
under the Boise River floodplain. All wells have been permitted by the Idaho
Department of Water Resources and logs are on file in their offices. See
Appendix Two for well details.
Water Quality /Security
The water quality is good and meets the public drinking water standards.
In addition to specific testing required by the IDEQ, EWC personnel perform
wellhead tests monthly. There have been no known problems with water
quality.
All well/pump house facilities are securely locked. Each facility is
inspected daily and the pumping quantities and pressures are recorded.
A Brief System History
Eagle Ranch Water Company was authorized as a public utility in 1976
bt the Idaho Public Utilities Commission ruled in case No. U-l116-, Order No.
12621. At that time, there were 150 customers and Well No.1 was the only
well in the system. As the customer base grew, Well No.2 was drilled and
integrated into the system. Eagle Hills subdivision water system was acquired
and it's well designated as Well #3. Due to problems of sand production,
however, Well No.3 has been removed from general operation and is currently
used only for backup.
In the 1980's, the company name was changed to Eagle Water Company,
Inc. Water meters were added in 1986 and the billing rate was changed from a
flat rate basis to a meter rate basis. Well No.4 was drilled and added to the
system in 1992. With the expansion of the City of Eagle, Well No.6 was drilled
in 1996 in order to:
) Serve the West side of the service area, and
) Provide additional supply for the system once this well was looped to
the North and connected to the existing EWC 12" mainline on
Floating Feather Road.3 (This connection has yet to be made.
WaterCAD(ID Modeling
Current ModelinQ; Project:
The modeling began in the Fall of 2005 utilizing Haestad Methods
WaterCADCID v7.0 software. The following input was required for the analysis:
i. Horizontal and vertical geometry
ii. Water source information
iii. Pumping information
iv. Consumption data
v. Performance criteria
i.) Horizontal and vertical Q;eometrv was obtained from the Company
and MTC's records. Pipe number and junction node numbers were assigned in
an AutoCADCID model. The model was imported as the background layer of the
WaterCADCID model and used as the guide in constructing the WaterCADCID
model. Node elevations were obtained from existing record drawings,
interpolating as necessary. The well locations were modeled as well as other
controlling hydraulic features. This established the base model.
ii.) Water source for the EWC system is pumped groundwater from five
wells. Information regarding the wells was obtained from the IDWR well logs,
test pump records, the Company records, and MTC'records. This
information includes: well stratigraphy, depth, diameter; casing and screen
placement; and pumpingjdrawdown data. A new well (Well #7) is located in the
NEI/4 of the SWI/4 of Section 15, TAN., RIE., B., Ada County, Idaho. Well #7,
under an IDWR permit, has been drilled and is been test pumped. It has been
3 The Floating Feather line is a major link to the higher East end of the service area. The service area has an
elevation difference of ~ 160 feet from its Westel1l edge, West of Well No.6 (elevation 2560 feet), to the
East end of Big Springs Boulevard (elevation 2720 feet). This equates to a pressure difference of 70::1::
pounds per square inch.
included in the model at the test pumping rate of 1250 gpm with a drawdown of
130 feet. Further testing may lead to a modification of these data.
iiL) Pump information was obtained from the pump identification plates,
manufacturer s catalogues, well logs and test pump records, and EWC records.
These included the pump manufacturer s performance curves, a primary piece
of information needed for the modeling. Information on the pump controller
settings for the variable speed pumps (VSP) and the fixed speed pumps with
on/off pressure settings was also provided by EWC.
iv.Consumption data for commercial and residential customers were
provided by the EWC. Consumption data for commercial customers were
acquired in a monthly format by commercial account and consumption data for
residential customers were acquired, by account, in both total-annual and
total-monthly formats. Total annual consumption in cubic feet (cf), was
obtained for the years 2002 through 2005, and used to generate the average
annual demand. Following analysis of the monthly consumption, and in
consultation with EWC's staff, data were obtained for the months of November
through January (to represent the average winter low demand season) and
June through August (to represent the average summer high demand season)
for the years 2002-3, 2003-, and 2004-
Commercial account consumption figures were entered into a Microsoft
EXCELCID spreadsheet program and the data manipulated, reduced, and
analyzed. The annual commercial account analysis resulted in an annual
average commercial demand being assigned to specific nodes as designated by
the EWC personnel.
Using the AutoCADCID/WaterCADCID model each residential account was
assigned to a specific node. An average annual residential consumption figure
was derived based on the total annual residential consumption figures from
2002 through 2005 and the number of dwelling units (D.s) served. The
average annual residential D.U. consumption was determined to be 0.3891
GPM/D.U. This was applied to the residential D.U. assignment at each node to
generate the node s residential demand. At this point, the model contained the
average annual composite demand. Using the winter and summer averages,
peaking factors were determined and applied to the average annual composite
demand to generate the average-winter and average-summer composite
demands. For the Maximum Day and Maximum Hour Peaking Factors were
selected from Dewberry & Davis' Land Development Handbook! as follows:
Maximum Day/Average Annual 1.80
Maximum Hour/Average Annual 2.
These values are similar to the values published in Seeley (1946)2 and Davis &
Sorensen (1969)3 and judged representative and acceptable. Using the average
summer composite demand as the parent demand, the maximum day and
maximum hour composite demand files were created. Diurnal patterns were
established for residential, commercial. and irrigation demands.
Following the initial analysis an effort was made to separate landscaping
(LS) water out as a separate item. It was found that the LS water in the
residential accounts could not be separated out. However, the LS water
accounts in the commercial accounts were identified by the EWC staff and then
entered as fixed seasonal demands in the average summer composite demands.
See Appendix Three for more information.
Performance criteria are listed in the general requirements for all
public water systems found in the Idaho Rules for Public Drinking Water
Systems (IRPDWS) and the Recommended Standards for Water Works (RSWW).
Additional information, supplementing the IRPDWS and RSWW, was provided
by Mr. Monty Marchus, P., IDEQ-Boise Office, in his Design File Notes (DFN)
titled Pressure Requirements-Public Water Systems and Design Flows-Public
Water Systems. Specific standards utilized in this modeling were pressure-
related rather than demand-related. For example , fire flow during the peak-
hour demand, including irrigation flows, requires satisfying the pressure
standards of 20 psi residual and a system-wide minimum of 20 psi.
WaterCADCID Modeling Results
Past Conditions Pre-2006 Scenario
The first models run were in the Pre-2006 scenario. The active topology
and initial settings were established to model the system as close as possible to
I Dewberry & Davis (1996).
Land Development Handbook. McGraw-Hill, New York
Seeley, Elwyn E. (1960). Data Bookfor Civil Engineers-Design. John Wiley & Sons, New York
3 Davis & Sorensen (1969).
Handbook of Applied Hydraulics. McGraw-Hill, New York
the system as it existed prior to 2006 when the hydrant flow tests were run.
Prior to 2006 several subdivisions near SH-55 and Floating Feather were not on
line; the 12" line crossing SH-55 to the booster station had not been re-
installed; the flow control valve on Old Horseshoe Bend Road was fully open;
and work on Well #7 had not been started. With the Pre-2006 model built,
thirteen hydrant flow tests from 2002 to 2005 were selected for comparison
runs. Each test was modeled separately and the calculated model residual
pressure was compared with the field record. The summary of the results is
shown in Appendix Four. Eleven of the 13 hydrant tests modeled produced
residuals from 1 psi to 37 psi (13-psi average) higher than the field results. Two
modeled lower by 20+ psi. Four extreme values were thrown out and a mean
value determined of 8.13 psi (SD=7.43 psi). The small differences between the
modeled residuals and the field residuals is probably due to differences between
the modeled demands and the actual system demands at the times of the field
tests. The model used figures averaged over several months from three to four
years records. A lack of detailed field demand data during the time of the flow
tests makes it impossible to precisely correlate the model residuals with the
field residuals.
Present Conditions 2006 Scenario
In the Present Conditions 2006 scenario, the active topology was updated
to include all service lines installed and all subdivisions currently being served;
the re-installation of the 12" trunk line across SH-55 to the booster station; and
the closing of the flow control valve on Old Horseshoe Bend Road. In addition,
Well #7 was modeled as on line and in service4
Using junction J-415 at the East end of Big Springs Boulevard as the
critical point, the updated model was run for the peak hour witl1 irrigation and
with fire flow at J-415. The Veteran s Cemetery service, areas Easterly and up
gradient of the intersection of Big Springs Blvd. and Bridle & Lariat Ways, and
the Northerly end of the line on Goose Creek Road, all East of Horseshoe Bend
Road, had resultant pressures less than the required 20 psi. Consequently, the
4 Well #7 is anticipated to be online late summer, 2006.
booster station pump was re-modeled vvith a pump capable of 2000+ gpm at
200+ foot head and the model re-run. This time the residual exceeded 30+ psi.
The Company has effectively zoned its system using gate valves as flow-
control valves. These are operated manually. The replacement of all these
manually operated pressure-controlling valves with automated pressure-
controlling valves would provide for smoother system operations and make the
fine tuning of the system easier.
Future Conditions 2006 Scenario - Items for further study.
No scenarios were run at this time due to the positive results obtained in
the Present Conditions 2006 Scenario analysis above. Various scenarios can be
run in the future to evaluate their ability to meet the requirements of future
growth. Further study could include items such as:
the addition of a "West End Connection" tying Well #6 into the 12-
inch mainline on Floating Feather Road
the extension of the 12-inch line through the proposed Optimist
Business Park to Horseshoe Bend Road,
the addition of a 12-inch line connection from Well #6 East to the
12-inch line at Eagle Road and SH-
the addition of a 12-inch replacement line on Floating Feather
from Eagle Hills Way to Edgewood Road, and
the increase of groundwater supply by new well construction and
existing well rehabilitation.
Exhibit "
Preliminary I1nplementation Plan
The Proposed Three-Phase Improvement Plan:
Phase lA - Increase pumping capacity
Completion of the fifth well (Well #7) to online status
Mid 2006 ($570,6402)
Phase 18 - Create upper pressure zoning
Installation of PRSV on Floating Feather Road
Late 2006 ($ 19,5002)
Upgrade pump at existing booster station
Winter 2006-($ 29,3602)
Phase 2 - Increase water resource, add looping, and improve pressure zoning
Construct an additional well near SH -55 /State Street, as needed
Explore potential storage requirements and possible alternatives
Explore need to loop from Well #6 to the 12" on Floating Feather Road
I All time estimates are contingent upon approval of financing by the IPUc.
2 Plus any and all legal, accounting, and permitting costs. Engineering and contingency costs are included.
Exhibit "
Preliminary Cost Estimates
The Proposed Three-Phase Improvement Plan:
Phase 1A - Increase pumping capacity
Completion of the fifth well (Well #7) to online status
Estimated Cost:$570,6401
Phase IB - Create upper pressure zoning
Installation of PRSV on Floating Feather Road
Estimated Cost:$ 19,5001
Upgrade pump at existing booster station
Estimated Cost:$ 29,3601
Phase 2 - Increase water resource, add looping, and improve pressure zoning
Construct an additional well near SH-55jState Street, as needed to
support future development
Explore potential storage requirements and possible alternatives
Explore need to loop from Well #6 to the 12" on Floating Feather Road
1 Plus any and all legal, accounting, and permitting costs. Engineering and contingency costs are included.
Exhibit "
Financing Plan
I"Id::! .,:)1 Ub UC:: U"Tp paper 208-939-6738 p. 1
Eagle Water Company
Calculation of Surcharge Amount Phase 1A
at May 31 2006
Cost of this Phase $ 570,640.
Financing Detail:
Amount Financed
Term
Interest Rate
Monthly Payments Required
$ 570 640.
7 years
10.00% * estimate based on current prime rate
$ 9,473.30 (approximate)
Annual Cash Required 113 679.
Multiplied by Gross-up (from below)127.88%
Total Annual Surcharge $ 145 373.47
Divided by Total Annual Revenue $ 711,440.
Surcharge 20.434%
.. Information supplied by Becky, Idaho Banking Co., 5/31/06
Estimated
Revenues
$ 555,790.
155 650.
$ 711 440.
Percent of
Total
78.12%
21.88%
100.00%
2005 Customers '
Residential
Commercial
Totals
Calculation of Gross-Up Factor for Taxes:
100.00% taxable
00%State Tax Rate
92.00% Federal Taxable
13.80%Effective Federal Tax Rate (Federal Rate 15%)
21.80% Composite Tax Rate 2) + 4)
78.20% Net After Tax Income
127.88% Gross-up Factor
"~"" ~L ......... ""'--UUf'"r-' cq-' E' 208 -939 -6738 p. 1
Eagle Water Company
Calculation of Surcharge Amount Phase 1 B
at May 31 , 2006
Cost ofthis Phase $ 45 860.
Total Surcharge
Multiplied by Gross-up (from below)127.88%
$ 58 645.
Divided by Total Annual Revenue $ 711 440.
Surcharge 243%
Estimated
Revenues
$ 555 790.
155 650.
$ 711 440.
2005 Customers
Residential
Commercial
Totals
Percent of
Total
78.12%
21 .88%
100.00%
Calculation of Gross-Up Factor for Taxes:
1 )100.00% taxable
00%State Tax Rate
92.00% Federal Taxable
13.80%Effective Federal Tax Rate (Federal Rate 15%)
21.80% Composite Tax Rate 2) + 4)
78.20% Net After Tax Income
127.88% Gross-up Factor