20121207Engineer Report.pdf

B1
DEC-7 AM T' 9
Brian Water crp6ration - Facility
Plan
Boise, Idaho
Brian Water Corporation
Prepared By:
Jesse Chan, P.E.
Diane Baconguis, P.E.
Brian Water Corporation Facility Plan
Level of Study
This technical document provides the alternatives of the appraisal level
engineering evaluation for bringing Brian Water Corporation into compliance
with IDAPA 58.01.08. This facility plan will identify the alternatives from which
the homeowners will choose a preferred alternative that will meet drinking water
standards of nitrate minimum contaminant level (MCL) and treatment
requirements, where appropriate.
Introduction and Background
Brian Water Company (J3WC) entered into a consent order (amended date
March 7, 2012) with the Idaho Department of Environmental Quality. BWC is
a community public water system (System) that serves forty six (46) homes,
refer to Appendix A-i and A-2. The system currently supplies drinking water
to the homeowners that does not meet the drinking water standards for
nitrate. Samples staked from the system show nitrate levels that exceed the
MCL of 10 milligrams per liter (mg/U.
Existing Conditions
Brian Subdivision is located near the intersection of Warm Springs Avenue
and Highway 21. It is outside the limits of the City of Boise in Ada County,
Idaho. The subdivision is flanked by the Boise River to the west and Hammer
Flats to the east. The subdivision has 48 homes. The remainder of the homes
has individual wells. Most of the homes in the subdivision were built in the
1970s, while others were built earlier in the 1960s.
Brian Water Company serves drinking water to 46 of the 48 homes in Brian
Subdivision, It is deemed unlikely that additional homes will be served by
the drinking water system. The community drinking water system has two
wells located in parcel legally described as Lot 2 Block 2, refer to Appendix A-
2. It is our understanding that well #1 has a flow capacity of approximately
110 cfs and has a depth of 75 feet and well #2 has a flow capacity of 110 cfs
and a depth of 80 feet. Both wells are contained in a well house. The wells
have no metering devices. Information on the capacity and depth of the wells
is based on the well driller's report and an approximation set forth by the
BWC's operator. The proximity to agricultural lands and the relatively
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Page 1
shallow depth of the wells has led to an increase in the nitrate levels of the
sources beyond the allowable MCL.
There are two homes that are not connected to the PWS. One home on 5890
Boven Drive has a 150-foot well, refer to Appendix A-2. Nitrate levels at the
well were at 0.6 mg/L, refer to Appendix C-3 and C-4. Another home on 6199
Brian Way has a 200+-foot well with nitrate levels at 0.2 mg/L, refer to
Appendix A-2 and C-S. The drill reports of these individual wells are
included in Appendix C-7 and C-8. The data from the well driller's reports of
these homes prove useful in terms of how deep new wells would have to be
drilled if BWC chooses to drill two completely new sources.
Figure 1. Location of Brian Subdivision on Warm Springs Avenue.
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Page 2
Evaluation of Alternatives
Rejected Alternatives
Several alternatives were considered to treat or replace the existing drinking water
sources. One alternative that was considered, but rejected, is to drill one well to a
minimum depth of 150 feet below ground surface. Provided that the new well
produces water that meets drinking water standards, water from that source would
be used to blend with the nitrate-contaminated water from the two existing
sources. This alternative has up-front uncertainties in cost to the homeowners.
BWC would have to drill a test well to a depth of at least 150 feet to determine the
capacity of the source and to test for water quality. If the test well indicates that
the hole will have to be drilled deeper due to insufficient yield or nitrate or poor
water quality, then the homeowners will be subject to even more uncertain costs
.beyond the cost of a test well. In addition, should the new well be subject to
maintenance or repair indefinitely, homeowners would be subject to contaminated
water from the remaining sources or Brian Water Corporation would be required
to inform homeowners of the potential of consuming high nitrate laden water
from the existing wells during the renovation or maintenance of the new well.
Another alternative was to drill deeper through the existing wells, but was
rejected due to the age of the existing wells. It is assumed that the existing wells
are of questionable condition. Also, there needs to be a redundant source at all
times.
Finally, the last alternative that was considered but rejected was to install an ion
exchange unit or a reverse osmosis system in each home. The reasons for
eliminating these alternatives include cost. More importantly, the installation of
individual treatment units puts the burden on the homeowner to purchase a unit
that will range from $400 to $1,500. It would also put the expense on the
individual homeowner to recharge a unit, which is one of the major costs of
maintenance and operation. Lastly, ion exchange and reverse osmosis units also
require constant monitoring of the unit to ensure that they are producing "clean"
water, a task that should not be the responsibility of BWC, not the homeowner.
Refer to Appendix C-9 through C-171 for reference information.
For the remainder of this section, the viable alternatives to mitigating or replacing
the existing drinking water system will be described. The following.alternatives
were analyzed:
• Connect to existing public drinking water system
• Incorporate ionization treatment at the source
• Drill two new wells
• Incorporate RO system at each house, for information only (HO)
Brian Water Corporation Facility Plan
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The engineer's preferred alternative will be given; however, it does not mean that
the BWC will choose the preferred alternative. BWC and Brian Subdivision have
the option to discard alternatives or selectively choose alternatives to develop into
a detailed predesign.
Connect to Existing Public Drinking Water System
The majority of the residences in the city of Boise are serviced by United Water
Idaho (UWI). Connection to UWI is an option that would require no
maintenance and operational efforts once the homeowners of Brian Subdivision
are connected. As an existing drinking water system, UWI monitors the water
quality and ensures adequate pressure and quantity of water to the customers they
service. UWI also has the technical, financial, and managerial capacity to
maintain their drinking water system. However, the nearest water main to Brian
Subdivision is located approximately 7,600 feet away. Assuming the installation
of an 8-inch pipe plus a pump station to maintain adequate pressure, the cost to
extend the water would be approximately $400,000 at minimum, refer to
Appendix E-2.
If BWC chooses to connect to an existing drinking water (i.e. United Water
Idaho), they would need to provide a written agreement with the existing water
system that provides a timeline of the connection to the existing distribution
system in Brian Subdivision. Similar to the remaining alternatives discussed in
this report, the cost to connect to an existing system would be a monumental
burden on the homeowners. Each homeowner would have to pay a minimum of
$8,700 to construct the lines and the booster pump that would allows them to
connect to the system.
Incorporate Ion Exchange Unit at the Sources
Another alternative to remediating the nitrate levels is to install nitrate removal
systems at the sources. The ion exchange unit works like a household water
softener. For nitrate removal, unit uses a resin that exchanges chloride ions for
nitrate (and sulfate) in the water. However, the resin only contains so much
chloride ions that is eventually depleted after so many gallons of water. The resin
is recharged of chloride ions using a concentrated solution of sodium chloride.
Backwash brine from recharging theunit will be in high nitrate concentration and
will require proper disposal, which is a large portion of the operation and
maintenance costs.
Another drawback of an ion exchange system is that the resin prefers the sulfate
exchange. It is not certain if the BWC sources are high in sulfate. Water high in
sulfate would reduce the system's effectiveness. Once the resin is saturated, it
releases nitrates in place of sulfates, which would increase the nitrate
Brian Water Corporation Facility Plan
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concentration in the water. Ion exchange also makes water corrosive, but the
water can be neutralized. The drinking water operator will need to be certified to
operate and maintain an ion exchange unit to ensure that the unit continues to
produce compliant water and will need to conduct continuous and frequent
monitoring of nitrate levels. Finally, ion exchange is expensive and requires
maintenance.
One study developed by the Minnesota Department of Agriculture and the
Minnesota Department of Health summarized the costs of several public water
systems that used ionization or reverse osmosis to remove nitrate from the
drinking water system, refer to Appendix C-9 through C-171. The study shows
that the cost per resident increases as the population served decreases. In their
example, the largest public water system is Lincoln-Pipestone Rural Water, which
serves 4,100 people. The construction cost of nitrate removal.added up to
$1,706,000, which amounted to $416 per resident. The summary also included
the cost to produce every 1,000 gallons of clean water assuming a 20-year
amortization (without interest expense) plus annual operating costs, which was
$1.35 for the Lincoln-Pipestone system. The smallest public water system was
Clear Lake, which serves 435 people. Their construction cost of nitrate removal
was $412,390, which was about $970 per resident. The cost to produce every
1,000 gallons of clean water was $4.38. For a very small community like BWC,
these extrapolated costs would be much higher. Based on the Minnesota study, an
extrapolated construction cost is estimated to be $190,066, or $1,358 per resident
and the cost to produce every 1,000 gallons of clean water would be $7.20, refer
to Appendix D-3. At an estimated per capita use of 0.14 acre-feet (WRIMIE
report, 2010), the annual water use of Brian Water is about 6.4 million gallons per
year. It would cost the BWC customers an estimated $46,080 per year to produce
clean water from their existing sources, or $329 per resident per year.
Drill Two New Wells
The system modifications would be designed using the following flows: total
consumption on a maximum day of 153 gallons per minute (GPM) and a peak use
for an expected one-hour duration of 308 GPM excluding fire flows, refer to
Appendix D-2. The flows were calculated based on 46 homes, 2.47 houses per
acre and a factor of safety of 2, in the absence of metered usage data from the
drinking water system. The design flow rates were estimated using the Design
Flows Calculation (dated 7/9/2007) spreadsheet provided by DEQ.
BWC has an estimate from a local drilling and pump company, refer to Appendix
E-5. The existing pumps have a capacity of 110 GPM, which we understand has
been adequate. The estimate was based on a 110 GPM standard or VFD pump
system at $29,734 or $32,645, respectively. This estimate is for one well. If this
well is not in operation, there must be another well that can provide the peak hour
demand flow, plus fire flows. BWC will be required to drill a second well of
Brian Water Corporation Facility Plan
Page 5
equal or greater capacity. The cost estimate provided will need to be revised for
drilling two wells that meet the peak hour demand of 308 GPM, plus what will be
required for fire flows, unless the 110 GPM is authorized. If the wells do not
provide sufficient flow for fire suppression, Brian Water will need to install
elevated storage to cover the fire flow requirement. Other concerns that will need
to be addressed if BWC chooses to install two new wells and the existing capacity
pump is not authorized is the water right. The drinking water standards require
more flow capacity than what the existing system provides. BWC will need to
request for sufficient water rights to meet the required capacity of the two new
wells. In addition, BWC will also need to request a waiver to drill in the same lot
as the existing wells as the current lot does meet current setback requirements.
Other significant costs not accounted for in this estimate are the operation and
maintenance costs to replace all of the mechanical parts of the drinking water
system. In addition to having a redundant source, Brian Water will need to
provide a generator that is large enough to maintain power in the largest well and
provide an automatic transfer switch to the generator in the event of a power
outage to avoid service interruption. A 20-year life cycle cost analysis to replace
the two pumps, the generator, and other mechanical parts, in addition to the power
requirement to maintain at least one of the pumps year round is shown in Table 1
below. In the long term, if the current owner can no longer manage or serve as
the drinking water operator of the system, the burden will be on the homeowners
to find the means to manage, operate, and-maintain the system.
Incorporate a Reverse Osmosis System in Each Home
(For Information Only) -
The system is a multifaceted system that includes a reverse osmosis (RO) system
that will remove 99 percent of most contaminants in the , waterand 70 percent of
any nitrate levels. The other 30 percent will be cleaned up by the deionization
canister filter which will take place of a "polish" carbon filter and will fit in one of
the bottom housings of the RO system. There is a monitoring system required
with an audible alarm to alert the homeowner of any problem associated with the
system. The alarm will plug into the system using a tee on the line going to the
faucet. A separate water line can be run to the refrigerator to supply clean water
to the refrigerator water dispensers.
This alternative is not considered due to yearly cost of item shown in life cycle
costs below.
Brian Water Corporation Facility Plan
- Page
Cost Estimate
Table 1 summarizes the initial cost of each alternative, the life expectancy, as well
as the annual cost for the life of each alternative.
Table 1. Cost Summary of all alternatives
Alternatives Initial Cost life Expectaney Annual Cost
Connect to Existing Drinking Water System $400,000 150 $2,667
Ineorporate Ion Exchange Unit at the Sources $190,000 5 $38,000
Drill Tw New Wells $81,000 20 $4,050
Inxporate RO Sys at houses (for info only) $40,020 1 2 1 $20,010
Life cycle cost information is prepared as a decision making tool. The costs
indicate an alternative's cost per year for the life of the alternative.
The cost estimate developed for this option is for the purpose of planning only
and is not intended to be at a the level required for construction.
Recommendation
All of these alternatives will be costly to the homeowners and it will impose
financial hardship on every single homeowner that is currently being served by
Brian Water as the cost of any of these alternatives will be passed on to them.
The ultimate goal of this report is to ultimately provide recommendation for what
would be the most reliable alternative source of safe and clean drinking water for
the homeowners at Brian Subdivision.
The recommended alternative is to connect to an existing drinking water, such as
United Water Idaho. First, once the homes in the subdivision are connected to the
system, the homeowners will have peace of mind that the quality of their water
will meet strict drinking standards and that they will always have adequate
pressure at the tap. Second, smaller drinking water systems are likely to have
more difficulty in meeting the increasingly stricter drinking water standards.
Third, the cost to maintain and operate a drinking water system once all standards
are met, may be high when considering the long term need to replace parts and
pay staff. A smaller drinking water system would have to relay a higher share of
those costs per household than a home that is connected to a large drinking water
system. Also, it is likely that property values will rise with the peace of mind that
a connection to a large, established drinking water system.
Brian Water Corporation Facility Plan
Page 7
APPENDIX E
BRIAN WATER CORPORATION
FACILITY PLAN
COST ESTIMATES
E-2 UWI CONNECTION
E-3 - E-4 HIDDLESTON 2012 WELL COSTS
E-5 IDAHO WATER SOLUTIONS REVERSE OSMOSIS COSTS
E-6 HIDDLESTON 2011 WELL/PUMP COSTS
E-1 BRIAN WATER CORPORATION - FACILITY PLAN APPENDIX E
UWI Connection Cost Estimate
Cost/ft of 8" pipe Length of pipe Booster pump and pump house Total
$50.00 1,600.00 $20,000.00 $400,000.00
E-2 BRIAN WATER CORPORATION - FACILITY PLAN APPENDIX E
Mountain Home bflic
j24Ci N W Beaman St
Mountain Home, ID 83647
208-58T-9055
f6x2561-9618
LEs
DRILLING & PUMP Co.
y . ,.hidd!estondrj!,pocrn
0-ffide
5932 W Victory'
BOiSe ID 83709
232-290O
20-36Z 97R:$
ESTIMATE
Dater October42012
Jesse'Charn
Bose,'Idaho
Phone: [phone].
Ernaih Jcha.rn33vecdrn:
RE: 1-8'* k 150. Corriffitylity well for'Brlan Water Corp. StibIvision, BOIse Idaho'
I Eath Drilling, Permit Comniunity Welt $22500 $225.00
100 Feet 12 Diameter Borehole $95.'GG $9,500,00
$0 Feet 8" Diameter Borehole $24 00 $i 200.00
.1$0 Feet 801casing $3327 $4,990.50
1 .Each 8"Drive..Shoe $3.4435 $34435
20, Feet 8" S$ Well Stren $187.92 $3,758.40
100 Each State of Idaho required Surface Seal $25 00. $2,500 00
DiiISubtotaL .. $22,518.25
Drillhg prices are based on current fuel prIces,Wé reserve the ritt to chargea reasonable;
fuel surcharge to cover fuel price kcreases.'
Thank:you for the opportunity-to bIdthTs.'prOjet,
Gary Oyler
.Hiddleston Drilling and Pump CO.
Accepted By' Date:_____________
Estimate good for 30days I 0F41201'2:
E-3 BRIAN WATER CORPORATION - FACILITY PLAN APPENDIX E