KWA - Preliminary Engineering Report - Sept 2009 - Appendix 7

8/7/2019 KWA - Preliminary Engineering Report - Sept 2009 - Appendix 7

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Jones&HenryEngineers,Ltd.

Lake Huron Water Supply Study

Appendix 7

Technical Memorandum

Reservoir and Reservoir Pump Station

Karegnondi Water Authority

o City of Flinto Genesee Countyo Lapeer Countyo Sanilac County

January 16, 2009


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Jones & Henry Engineers, Ltd.

7.1 RESERVOIR

7.1.1 General

This technical memorandum describes the general design criteria for an upground reservoir and reservoirpump station as components of the Lake Huron Water Supply Study.

7.1.2 Reservoir Size

The raw water reservoir has been sized to hold 94 percent of the projected 25-year, maximum-daydemand (MDD) or 78.5 mgd for a period of 7 days, plus an approximate 20 percent of additional workingvolume. This is considered a sufficient amount of time to make any emergency repairs to the pipeline,pumping station, or other. The additional working volume would be to maintain a minimum pool depthand possible water quality issues that comes with shallow water. The reservoir will turn over in terms ofvolume several times in the course of a year. The number of times is contingent on the volume of waterused. Seasonally, the reservoir will turn over (temperature inversion) twice.

In terms of water loss due to evaporation, there should be an approximate balance from precipitationannually. At times, there will be some water loss from evaporation during hot dry weather, but the lossshould be negligible percentage wise.

Seepage loss through the levee could be significant if it is not properly constructed with liners to reducethe loss. Bentonite clay liner of one-foot thick has been assumed in the cost estimate to reduce seepage.Final Design should include a blanket drain or toe drain at the base of the levee to accommodate seepage.

There is no ideal depth of water for a reservoir; generally, the deeper the better. A typical depth of 35 feet

has been selected. Reservoirs with depths less than 20 feet will have seasonal excess blue-green oranother algae growth with subsequent water quality problems.

The following is the recommended reservoir size for 2014 through 2039 and for a second cell to beconstructed by the year 2039:

Required Volume = 7 days x 0.94 x 78.5 mgd = 516.5 mg + 20 % = 620 mg

Wetted Perimeter Total 20 Total 2039

62 acres 100 acres 190 acres

The recommended size includes acreage to construct a reservoir pump station with access roads.

7.1.3 Reservoir Details


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As an alternative to the rate control valve, a minimum three million gallon storage tank should beconstructed on the bypass line to accommodate differences in pumping rates of the two pump stations (seeFigure 1).

Maintenance will include vegetative control (mowing) as well as control of burrowing animals andmaintenance and monitoring of drainage tiles.

A very preliminary study of the proposed property was conducted. Using well logs in the area andpublished geological information of that regional area. The conclusion was that it does appear that there

may be significant quantities of clay bearing soil materials from which to construct dikes with liners.

A typical reservoir cross section is shown in Figure 2. Actual recommendations for type and thickness ofliners can only be made after a thorough site investigation.

A single line entering near the top of the reservoir to prevent draining in the event of a pipe break isrecommended with a sediment trap (Figure 3). The trap will provide sufficient time for heavier solids tosettle out. The trap will have to be cleaned periodically.

A multi-port outlet structure will be provided (Figure 4). Sluice gates would be mounted at variousheights. A single sluice gate would be opened in order to draw off the best quality water. The best waterquality depth could change seasonally or for some other reason. The outlet structure could be accessed bya bridge from the top of the dike (vandal potential) or by boat (inconvenient). An overflow/reservoir drainstructure would be provided (Figure 5). The discharge line would run to an appropriate point. Nochemical feed provisions are contemplated. Hand broadcasting of copper sulfate via boat would likely benecessary at the onset of summer for curtailing blue-green algae.

An outfall structure will be provided to dissipate energy in the event of an accidental overflow.

7.1.4 Identification of Site

There are a number of potential sites in the area that may be suitable for an upground reservoir.

Sites in the area have significant changes in the topography and may be difficult if not impossible toachieve an earth balance. However, there will be more than sufficient backfill available from constructionof the transmission lines if needed.

A thorough evaluation will be necessary including an environmental site assessment and a wetlandsstudy.

7.1.5 Permitting


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As may be expected, the water quality will not be quite as good as directly from Lake Huron. However,because of its large size for any alternative and the multi-port outlet, it should not diminish by much.Seasonal application of copper sulfate will probably be a requirement. The small amount of copper sulfateapplied has no effect on corrosion and negligible effect on lead/copper programs.

7.1.7 Security

An eight foot high chain link fence with barbed wire around the entire reservoir site is recommended. Aseparate eight foot high chain link fence with barbed wire is recommended for the reservoir pump station.

7.1.8 Ice

Withdrawing water at a low velocity and choosing the proper outlet to withdraw water should eliminateany problems of ice in the reservoir pump station. A means of back flushing the intake line utilizing thereservoir pumps could be considered.

7.1.9 Construction CostTable 7-1

Estimated Reservoir Construction Cost

Item Unit Cost UnitEstimatedQuantity

EstimatedCost

Mobilization $100,000 Lump Sum 1 $100,000

Clearing $6,500 Acre 100 $650,000

Embankment $3.50 Cubic Yard 1,337,000 $4,679,500

12-inch Bentonite Liner $13,000 Acre 80 $1,040,000

Rip-Rap Liner $40 Cubic Yard 56,000 $2,240,000

Seeding $2,500 Acre 35 $87,500

Blanket Drain $30 Ton 36,200 $1,086,000

Structures $100,000 Each 5 $500,000

Access Roads $15 Ton 7,000 $105,000

Security Fence $18 Lineal Feet 9,500 $171,000

Subtotal $10,659,000

15% Construction Contingency $1,598,850

5% Design Contingency $532,950

17% Engineering, Legal, Bond,and Administrative $1,812,030

Total Construction Cost $14,602,830

The alternative three million gallon bypass storage tank would add an additional $2,800,000 to thesubtotal or $13,459,000 and bring the total construction cost to $19,784,730.


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7.2 RESERVOIR PUMP STATION

7.2.1 General

The pump station has been sized to provide the projected 25-year, maximum-day demand (MDD) for theproposed Genesee County Water Treatment Plant, Flint Water Treatment Plant, and Lapeer TreatmentPlant. Additional space will be provided for two future pumps and upsizing the original pumps to meetprojected 50-year demands.

The pump station can be considered two stations housed in a common building. The North Pump Stationwill have pumps which can be dedicated to pumping into the north transmission main and the SouthPump Station will have pumps which can be dedicated to pumping into the south transmission main. Onebackup pump will be able to serve either the north or south pump stations. Under normal circumstancesany or all of the pumps will pump through both lines.

7.2.2

7.2.3

Pumps and Piping

Five 20 mgd 400 Hp horizontal split case pumps will be provided, drawing water from the reservoirwith a common intake header and discharging into a common discharge header. The headers will bevalved so that two pumps can be dedicated to discharging through the north transmission route and twopumps can be dedicated to discharging through the south route. The fifth backup pump can be valvedthrough the headers to serve either the north or south routes. In an emergency, any or all of the five pumpscan pump to either route. (See schematic design drawing Figure 6). Normal operation would be to haveone or two pumps pumping through both routes to meet average-day demand. See Tables 7-4, 7-5, 7-6,and 7-7 for average, maximum, and emergency demands. Three pumps running can meet the north routeemergency demands; however, emergency demands using the south route will require four pumps

running.

The pumps will be provided with Variable Frequency Drives (VFDs) to control the rate of flow requiredat each treatment plant and to accommodate the differences in total dynamic head (TDH) between thenorth and south transmission lines routes.

An engine generator will provide one hundred percent backup power. The generator will be sized to becapable of running any four pumps.

Standby Power

7.2.4Bulk chemical storage tanks will be provided for pretreatment of the raw water. Two complete sets offeed systems will be provided and dedicated to each of the north and south transmission mains routes. The

Chemical Storage and Feed


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7.2.6 Construction Cost

Table 7-2Estimated Reservoir Pump Station Construction Cost

DescriptionEstimated

Cost

Structures $3,400,000

Equipment $2,300,000

Piping and Valves $1,800,000

Electrical $3,700,000

Subtotal $11,200,000

15% Construction Contingency $1,680,000

5% Design Contingency $560,000

17% Engineering, Legal, Bond, and Administrative $1,904,000

Total Construction Cost $15,344,000

7.2.7 Schedule

Many of the equipment items for the pump station will require long lead times for shop drawing approval,manufacturing, delivery, and installation. The reservoir pump station could take 18 to 20 months tocomplete and place in service.


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7.3 ANNUAL OPERATIONS AND MAINTENANCE (O&M) COSTS

7.3.1 General

Chemical costs for pretreatment at the reservoir pump station are unknown. An estimated allowance itemhas been added to the O&M costs.

7.3.2

$20 per hour for operators

Annual Operating Costs

The following assumptions were made for operating costs:

Power cost based on 6.3 cents per kilowatt hour.Direct Labor Costs based on the following labor rates:

$25 per hour for maintenance mechanics $15 per hour for seasonal workers

For the reservoir pump station, one operator for four hours each work day has been assumed. For thereservoir, one seasonal worker full time for four months. The daily operator could assist the seasonalworker occasionally and care for the reservoir in addition to the reservoir pump station during theremaining months. All per hour costs are increased by a 1.62 multiplier for fringe benefits.

7.3.3

Equipment 5 % of original cost (20 years)

Annual Maintenance Costs

Maintenance costs were assumed as follows:

Piping and Valves 2-1/2 % of original cost (40 years) Structures 1-1/3 % of original cost 75 years)

Table 7-3Annual Operation and Maintenance Costs

Reservoir and Reservoir Pump Station

Operating CostsLabor $39,886Power * * $168,626

Chemicals $50,000Subtotal $258,512

M i t C t


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MAX DAY FLOW RATE 23,799 gpm 34.27 mgd

Usage by Genesee County 10,563 gpm 15.21 mgdUsage by Flint 11,472 gpm 16.52 mgdUsage by Lapeer 1,764 gpm 2.54 mgd

SOUTH ROUTEFlow Reservoir to Lapeer - gpm mgdPipe Diameter (D = inches) 60 inches 5 ft

Pipe Length (L = feet) 44,930 ft 8.51 milesHazen & Williams Fric. Factor (C) 120

Velocity - ft/sFriction head loss 0.00 ft 0.00 psi

Lapeer to Genesee CountyDesign Flow Rate - gpm - mgdPipe Diameter (D = inches) 54 inches 4.5 ft

Pipe Length (L = feet) 28,520 ft 5.40 milesHazen & Williams Fric. Factor (C) 120Velocity - ft/sFriction head loss 0.00 ft 0.00 psi

Total Headloss from Reserv. to Genesee Co. 0.00 ft 0.00 psiDifference in Elevation 50.00 ft

Head Needed on Pump For Friction Loss -50.00 ft

Additional Head to Clear Hills 84.50 ftTotal Head Needed on Pumps: To Genesee Co. 84.50 ft

NORTH ROUTEComplementary Flow North Route 23,799 gpm 34.27 mgpd

Table 7- 4CURRENT AVERAGE DAY DEMAND / TWO LINES

Friction Loss, Head, & HP Estimates

Pipe Diameter (D = inches) 54 inches 4.5 ft

Pipe Length (L = feet) 77,760 ft 14.73 miles

Hazen & Williams Fric. Factor (C) 120Velocity 3.33

Friction head loss 53.78 ft 23.30 psi

Difference in Elevation 50.00 ftHead Needed on Pump For Friction Loss 3.78 ft

Additional Head to Clear Hills 0.00 ftTotal Head Needed on Pumps: To Genesee Co. 25.00 ft

Genesee County to FlintDesign Flow Rate 11,472 gpm 16.52 mgdPipe Diameter (D = inches) 48 inches 4 ftPipe Length (L = feet) 74,560 ft 14.12 miles

Hazen & Williams Fric. Factor (C) 120Velocity 2.03 ft/s

Friction head loss 23.71 ft 10.27 psiTotal Head Needed on Pumps: To Genesee Co. 25.00 ft 10.83 psi

Additional Head to Clear Hills 26.49 ftTotal Head Needed on Pumps: To Flint 51.49 ft

Power RequirementsAssumed efficiency 85%Power Required 400 h p 298 73 kw


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MAX DAY FLOW RATE 31,840 gpm 45.85 mgdUsage by Genesee County 12,215 gpm 17.59 mgd

Usage by Flint 13,368 gpm 19.25 mgd

Usage by Lapeer 6,257 gpm 9.01 mgd

SOUTH ROUTE

Flow Reservoir to Lapeer 3,132 gpm 4.51 mgd

Pipe Diameter (D = inches) 60 inches 5 ft


Hazen & Williams Fric. Factor (C) 120

Velocity 0.36 ft/s


Lapeer to Genesee County

Design Flow Rate - gpm - mgd



Hazen & Williams Fric. Factor (C) 120Velocity - ft/s


Total Headloss from Reserv. to Genesee Co. 0.44 ft 0.19 psi

Difference in Elevation 50.00 ft


Additional Head to Clear Hills 84.62 ft

Total Head Needed on Pumps: To Genesee Co. 84.62 ft

Table 7- 525-YEAR AVERAGE DAY DEMAND / TWO LINES


NORTH ROUTE

Complementary Flow North Route 28,708 gpm 41.34 mgpd






Head Needed on Pump For Friction Loss 26.09 ft



Genesee County to Flint

Design Flow Rate 13,368 gpm 19.25 mgd




Velocity 2.37 ft/s


Total Head Needed on Pumps: To Genesee Co. 36.55 ft 15.83 psi



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MAX DAY FLOW RATE 54,528 gpm 78.52 mgdUsage by Genesee County 24,160 gpm 34.79 mgdUsage by Flint 20,056 gpm 28.88 mgd

Usage by Lapeer 10,313 gpm 14.85 mgd

SOUTH ROUTE





Velocity 2.84 ft/s








Total Headloss from Reserv. to Genesee Co. 28.54 ft 12.36 psi





Table 7- 625-YEAR MAXIMUM DAY DEMAND / TWO LINES


NORTH ROUTE

Complementary Flow North Route 29,497 gpm 42.48 mgpd














Velocity 3.56 ft/s





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SOUTH ROUTE


Lapeer to Genesee County 32,903 gpm 47.38 mgd

Genesee County to Flint 14,729 gpm 21.21 mgd

Flow Reservoir to Lapeer











Velocity 4.61 ft/sFriction head loss 35.91 ft 15.56 psiTotal Headloss from Reserv. to Genesee Co. 86.57


Desi n Flow Rate 14 729 m 21.21 m d

Table 7-7

75% of Maximum Day / South Route Only


25 YEAR EMERGENCY CONDITIONS

,




Velocity 2.61 ft/s


Total Friction Head Loss 124.22 ft 53.81 psi

Total Head Needed on Pump 97.86 42.39 psi

Minor Loss & others (10%) 9.79 4.24 psi

Total Head 107.64 ft 46.63 psi

Power Requirements

Assumed efficiency 85%

Power Required 1438 h.p 1073.03 kw

Assumed number of pumps

operating simultaneously 4

Pumping Rate 10,222 gpm 14.72 mgd

Power Required (each pump) 360 hp 268.26 kw


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MAX DAY FLOW RATE 33,161 gpm 47.75 mgdUsage by Genesee County 18,120 gpm 26.09 mgd

Usage by Flint 15,042 gpm 21.66 mgd

Usage by Lapeer - gpm mgd

NORTH ROUTE

Flow North Route 33,161 gpm 47.75 mgpd

Pipe Diameter (D = inches) 54 inches 4.5 ftPipe Length (L = feet) 77,760 ft 14.73 miles


Velocity 4.65









Table 7- 825-YEAR EMERGENCY CONDITIONS

75% of Maximum Day / North Route Only




Velocity 2.67 ft/s



Additional Head to Clear Hills 48.43 ftTotal Head Needed on Pumps: To Flint 106.55 ft

Power Requirements

Assumed efficiency 85%

Power Required 1155 h.p 861.39 kw

operating simultaneously 3

Pumping Rate 11,054 gpm 15.92 mgdPower Required (each pump) 385 hp 287.13 kw


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North Route from Reservoir to Genesee WTP

frictionloss g

radient

HGL to meet Flints needs

Elev.=74

7ft(weir)

friction loss gradient

HGL needed to clearhills

Q = 21.66 mgdPipe Size = 48 inchesVelocity = 2.67 fpsFriction head Loss = 39.14 ft

FLINT TRANSMISSION LINE

103

ft

NORTH ROUTE PUMPING TO FLINT WTPEMERGENCY CONDITIONS

75% OF MAXIMUM DAY DEMAND

Q = 47.75 mgdPipe Size = 54 inchesVelocity = 4.65 fpsFriction head Loss = 99.35 ft

Genesee Co. WTP

Reserv. P

HGL needed

to clear hills

FIGUHGLEvalofNor

th&

SouthRoute.cdr

Dec-11-2008

Cut

Cut


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54

ft

friction los

s gradient

Q = 58.88 mgdVelocity = 4.64 fpsFriction head Loss = 54.17 ft

Reserv. PS

Genesee Co. WTP

44

ft

SOUTH ROUTE PUMPING TO FLINT WTP

HGLneed

ed toclear

hills

Elev.=747ft(w

eir)

friction loss gradient

HGL needed to clearhills

Q = 21.21mgdVelocity = 2.61 fpsFriction head Loss = 24.26 ft

FLINT TRANSMISSION LINE

EvaluationSouthRouteOnly.cdr

Jan-13-2009

Lapeer

Cut

Cut

Cut

Cut

Q = 47.38 mgdVelocity = 4.61 fpsFriction head Loss = 39.89 ft

Documents

KWA - Preliminary Engineering Report - Sept 2009 - Appendix 7