Technical Memorandum December 2011 - … · Feasibility Study Technical Memorandum ... 44422\Final White Paper \Final White Paper_Technical Memorandum December 2011.doc Page 2

$Page 1: Technical Memorandum December 2011 - … · Feasibility Study Technical Memorandum ... 44422\Final White Paper \Final White Paper_Technical Memorandum December 2011.doc Page 2$
City of Lompoc Onsite Untreated Groundwater Irrigation Well

Feasibility Study

Technical Memorandum

December 2011

1199 S. Fullerton Road City of Industry, CA 91748-1232

(626) 912-3391 www.lee-ro.com

City of Lompoc Onsite Untreated Groundwater Well Feasibility Study December 2011 Page 2

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TTEECCHHNNIICCAALL MMEEMMOORRAANNDDUUMM Date: June 9, 2010 To: Gene Margheim, City of Lompoc From: Tom Holliman, LEE & RO Subject: Onsite Untreated Groundwater Well Feasibility Study 1. Introduction and Overview

The City of Lompoc (City) is considering allowing the development of local irrigation wells to provide untreated groundwater for landscape irrigation at local schools and parks. Several schools and parks were identified as potential location for untreated groundwater irrigation wells. These include,

Schools: • Clarence Ruth Elementary • Filmore Elementary • Hapgood Elementary • La Canada Elementary • La Honda Elementary • Lompoc Valley Middle School • Miguelito Elementary • Mission Valley School • Lompoc High School

Parks:

• Barton Park • Beattie Park • Briar Creek Park • Johns-Manville Park • Ken Adam Park • Ryon Park • Thompson Park • Westvale Park

The purpose of this study is to determine the feasibility of developing onsite untreated water irrigation wells for landscape irrigation versus continuing to purchase treated water from the City of Lompoc. Exhibits showing each site and a proposed location for the well, connecting piping, electrical power connection, and electrical conduit, are included in the report. It should be noted that College Park and Centennial Park were eliminated from further consideration due to the very limited demand and lack of space to install a well.



2. Untreated Irrigation Water Demand Evaluation

LEE & RO first evaluated each of the candidate sites to determine the potential untreated groundwater demand. The assumption was that the schools would continue to provide treated City water for drinking, toilet flushing, and local irrigation around the classrooms. Only landscaping areas would be converted to use the untreated groundwater. LEE & RO examined historical water demand records for the candidate sites and conducted field visits. Where complete water usage data was not available estimates were made based on the size of the irrigated areas and demand rates from the other schools or parks.

To determine the percentage of the existing treated City water demand that could be switched to the untreated groundwater system an estimated percentage was used. The percent usage factors for different types of uses are shown in Table 1 – Potential Water Demand by User Type.

Table 1 Potential Untreated Groundwater Demand by User Type

Type No. User Type

Potential Use

Type No. User Type

Potential Use

1 Agricultural 95% 22 Landscape 100% 2 Apartment 70% 23 Laundry 90%

3 Automobile Dealer 80% 24 Manufacturing 60%

4 Bank 85% 25 Metal Finishing 50% 5 Car Wash 90% 26 Metal Plating 50% 6 Cemetery 95% 27 Nursery 95% 7 Church 85% 28 Nursing Home 50% 8 City 100% 29 Office 90% 9 Construction 50% 30 Paper Recycle 95% 10 County 90% 31 Park 85% 11 Day Care 50% 32 Post Office 85% 12 Dry Cleaner 20% 33 Power Plant 90%

13 Fabric Dyeing 95% 34 Property Mgt 85%

14 Food Process 5% 35 Recharge 100%

15 Gas Station 20% 36 Restaurant 5% 16 Golf Course 95% 37 Retail 50% 17 Health Care 65% 38 School 65% 18 Health Club 85% 39 Storage 90% 19 HOA 70% 40 Supermarket 50% 20 Hospital 20% 41 Theater 90% 21 Hotel 20% 42 Warehouse 50%

43 Water Purification 90%

Percent Use = Percentage of current consumption that may be converted to recycled water.



The list of candidate sites and their respective untreated groundwater demands are shown in Exhibit A. The total potential untreated groundwater demand is 142.36 AFY.

3. Cost of Developing Local Untreated Water Supply

In order to evaluate the feasibility of developing local untreated groundwater supplies the total cost for each site must be developed. These costs include all construction costs to establish the well, and then the annual operation and maintenance (O&M) costs. The total annual cost of construction and O&M is then compared to the cost of purchasing City treated water. A summary of all costs is shown in Exhibit A. A description of each element is provided in the sections below.

A. Construction Cost

i. Depth to Groundwater

In order to size potential irrigation wells and develop the required pump capacities a depth to groundwater of 200 ft was assumed. This is consistent with the City’s groundwater management plan.

ii. Irrigation Pump Horsepower Required

To develop the required horsepower for the pump motors it was assumed that the irrigation would take place over a period from 9 PM to 6 AM which are normal irrigation hours which would result in a peaking factor of 6.9. This peaking factor was used to size the output of the irrigations pumps

iii. Well Construction Cost Including Pump

Well construction costs were developed from costs received from a local well contractor located in the City of Lompoc. A & A Pump and Well Service provided cost estimates for various pumps based on the horsepower requirements developed for each site. The cost of drilling the well was also quoted and was used for all well sites. A copy of the proposal from A & A Pump and Well Service is contained in the Appendix.

iv. Electrical Power Panel/Base

This cost was derived from previous projects by LEE & RO and were assumed to be the same for each site. It further assumed that the electrical meter could be provided at the same point the existing power enter the site and would not require a new service connection from the street.

v. Pipeline Cost

Pipeline installation between the well and the existing RPPD was assumed to be $60/LF based on construction on the site and without pavement excavation or replacement. If the lateral from the pump to the existing RPPD connection must be



installed in the street the cost will be approximately $120/LF. These costs are consistent with other similar LEE & RO projects.

vi. Power Conduit Cost

Electrical conduit installation between the power panel and the pump was assumed to be $25/LF based on construction on the site and without pavement excavation or replacement. This cost includes 4-inch PVC conduit, wires, and a burial depth of 24-inches. If the electrical conduit from the pump to the existing power panel must be installed in the street the cost will be approximately $100/LF. These costs are consistent with other similar LEE & RO projects.

vii. Onsite System Modifications/Marking/CDPH Documentation

In order to provide untreated groundwater only to the irrigation systems on the sites the existing irrigation system must be disconnected from the existing potable system and new piping installed to the irrigation well. In addition non-potable systems must be identified with color coding and signage. The California Department of Public Health must be notified that there is an auxiliary water supply on site and appropriate documentation will be required. The cost of this work is assumed for each school site to be $10,000, and for each park to be $5,000. These cost figures are consistent with other LEE & RO onsite conversion projects.

viii. Total Construction Cost

A total construction cost was developed for each site as shown in Exhibit A. In order to develop annual costs for construction it was assumed at the cost of construction would be spread over ten years with a 5% cost of funds applied. The total cost of construction including interest will be $1,143,000, or an average annual cost of $114,300 for ten years for all of the sites combined.

B. O&M Cost

i. Cross Connection Testing

For each site annual cross connection testing will be required because the site now has both potable water and an untreated auxiliary water supply. Under Title 17 of the California Water Code the testing will be required. LEE & RO’s experience has been that school sites will be required to test annually and provide the information to the California Department of Public Health. Based on other cross connection testing contracts a unit cost of $2,000 per site was used for the schools. Because the parks are typically not considered high risk sites such as schools only testing once in four years is typically required, therefore a unit price of $500 per park site was used.

ii. Annual Pump Maintenance

It was assumed that although the pumps were small that a minimum of one visit per month would be reasonable and an annual cost of $1,500 per site was assumed. It was further assumed that no repairs would be required within the



first ten years of operation and that no capital recovery cost would be included to replace the pumps at the end of their service life.

iii. Power Cost

A power cost of $0.13/KwH was assumed for power, and that the pumps would be operated five days a week, eight months each year (allowing for winter rains and reduced irrigation).

iv. Debt Service Repayment

Currently all water customers pay $0.40/CCF for existing fixed debt on the water system. If the schools and parks begin to take auxiliary water for irrigation the debt service must be paid for the user or the rest of the City of Lompoc customers will see the debt service cost passed back to them. For the purposes of this analysis this debt service obligation was carried forward as an annual O&M cost.

v. Total O&M Cost

A total annual O&M cost was developed for each site as shown in Exhibit A. The total cost of O&M will be $146,300 for all of the sites combined.

vi. Annual Cost of City Water

The current City potable water rate of $2.75/CCF was used to generate the current cost of City treated potable water for irrigation for each site. The total combined cost of City treated potable water is $170,600.



4. Results and Recommendation

Site Name

Total Water

Demand (AFY)

Irrigation Demand

(AFY)

Total Construction

Cost ($)

Annual Construction Cost (10 yr.

Amortization)

Total Annual O&M

Cost ($)

Total Cost Construction

+ O&M

Cost of City Water

Clarence Ruth Elementary 9.00 5.85 $ 74,700 $ 9,700 $ 7,700 $ 17,400 $ 7,100

Filmore Elementary 10.00 6.50 $ 81,900 $ 10,700 $ 7,800 $ 18,500 $ 7,800

Hapgood Elementary 11.00 7.15 $ 40,000 $ 5,200 $ 7,900 $ 13,100 $ 8,600

La Canada Elementary 18.00 11.70 $ 62,900 $ 8,200 $ 15,300 $ 23,500 $ 14,100

La Honda Elementary 12.00 7.80 $ 43,800 $ 5,700 $ 8,000 $ 13,700 $ 9,400

Lompoc Valley Middle School 8.00 5.20 $ 60,600 $ 7,900 $ 7,600 $ 15,500 $ 6,300

Miguelito Elementary 7.00 4.55 $ 83,600 $ 10,900 $ 5,900 $ 16,800 $ 5,500

Mission Valley School 3.35 2.18 $ 50,500 $ 6,600 $ 5,500 $ 12,100 $ 2,700

Lompoc High School 28.00 18.20 $ 49,400 $ 6,400 $ 16,400 $ 22,800 $ 21,900

Barton Park 10.00 8.50 $ 36,000 $ 4,700 $ 6,600 $ 11,300 $ 10,200

Beattie Park 21.00 17.85 $ 66,800 $ 8,700 $ 14,900 $ 23,600 $ 21,400

Briar Creek Park 9.00 7.65 $ 30,400 $ 4,000 $ 6,500 $ 10,500 $ 9,200

Johns-Manville Park 10.00 8.50 $ 37,600 $ 4,900 $ 6,600 $ 11,500 $ 10,200

Ken Adam Park 9.00 7.65 $ 36,900 $ 4,800 $ 6,500 $ 11,300 $ 9,200

Ryon Park 20.00 17.00 $ 51,000 $ 6,700 $ 14,700 $ 21,400 $ 20,400

Thompson Park 5.00 4.25 $ 32,600 $ 4,300 $ 4,400 $ 8,700 $ 5,100

Westvale Park 2.15 1.83 $ 37,300 $ 4,900 $ 4,000 $ 8,900 $ 2,200

142.36 $ 876,000 $ 114,300 $ 260,600 $ 170,600

*Centennial Park and College Park are not considered due to small irrigation demand. *Well construction cost (include equipment) based on estimate from A & A Pump & Well Service.

*Assumed pipeline unit price : $60/LF *Assumed power conduit unit price : $25/LF

Cost of treated water = $1,198/AFT Assumed Interest Rate 0.05 Amortization Period 10 years

Based on the analysis, the total annual cost of operating the untreated groundwater wells is higher than purchasing City treated water. Therefore it remains more cost effective for the schools and parks to remain on City treated groundwater rather than developing a local onsite untreated groundwater supply for irrigation.

EstimateDate

12/8/2011

Estimate #

557

Name / Address

Sung Choy

In Reference To

A & A PUMP & WELL SERVICE123 INDUSTRIAL WAYBUELLTON, CA 93427ST LIC # 577455

Thank You This bid may be revised after 14 days

Signature________________________________

Phone #805-688-8805Fax #805-686-8282

Total

Subtotal

Sales Tax (7.75%)

Date____________________

If you have any questions, please give us a call. If you would like to proceed with the work listed above, please sign and return a copy of this estimate. Payment is due upon completion.

DescriptionQty Cost Total

County Drilling Permit 750.00 750.00Drill 12" Bore, Case with 6" PVC & Provide .032 Screen where needed250 50.00 12,500.00Provide #8 (Lapis #3) sand pack 0.00 0.00Provide 50 foot sanitary seal 1,500.00 1,500.00

$14,750.00

$14,750.00

$0.00

EstimateDate

12/8/2011

Estimate #

558

Name / Address

Sung Choy

In Reference To

A & A PUMP & WELL SERVICE123 INDUSTRIAL WAYBUELLTON, CA 93427ST LIC # 577455

Thank You This bid may be revised after 14 days

Signature________________________________

Phone #805-688-8805Fax #805-686-8282

Total

Subtotal

Sales Tax (7.75%)

Date____________________

If you have any questions, please give us a call. If you would like to proceed with the work listed above, please sign and return a copy of this estimate. Payment is due upon completion.

DescriptionQty Cost Total

Grundfos 25S50-26 with Franklin Electric 4" 5 Horsepower460 Volt Motor 2,022.75 2,022.75TGrundfos 150S200-10 with Franklin Electric 6" 20 Horsepower 460 VoltMotor

5,199.00 5,199.00T

Grundfos 85S100-9 with Franklin Electric 6" 10 Horsepower 460 Volt Motor 3,824.25 3,824.25T

$11,902.07

$11,046.00

$856.07

EXHIBIT A - City of Lompoc - Park/School Irrigation

Site Name

Total

Water

Demand

(AFY)

Irrigation

Demand

(AFY)

Average

Irrigation

Demand

(GPM)

Peak

Hour

Irrigation

Demand

(GPM)

Average Depth

to

Groundwater

(FT)

Irrigation

Pump HP

Required

(HP)

Well

Construction

Cost

($)

Electrical

Pedestal

w/motor

starter

($)

Pipeline Cost

($)

Power

Conduit Cost

($)

Irrigation

System

Modifications

($)

Total

Construction

Cost ($)

Annual

Construction

Cost (10 yr

Amortization)

Cross

Connection

Testing

($/year)

Annual

O&M Cost

($)

Annual

Power ($)

Debt Service

Repayment

$0.40/BU

Total

Annual O&M

Cost ($)

Total Cost

Construction +

O&M

Cost of City

Water

Clarence Ruth Elementary 9.00 5.85 3.63 25.04 200.00 10.00 18,900$ 5,000$ 39,600$ 1,125$ 10,000$ 74,700$ 9,700$ 2,000$ 1,500$ 3,100$ 1,100$ 7,700$ 17,400$ 7,100$

Filmore Elementary 10.00 6.50 4.03 27.82 200.00 10.00 18,900$ 5,000$ 45,120$ 2,800$ 10,000$ 81,900$ 10,700$ 2,000$ 1,500$ 3,100$ 1,200$ 7,800$ 18,500$ 7,800$

Hapgood Elementary 11.00 7.15 4.43 30.60 200.00 10.00 18,900$ 5,000$ 2,280$ 3,750$ 10,000$ 40,000$ 5,200$ 2,000$ 1,500$ 3,100$ 1,300$ 7,900$ 13,100$ 8,600$

La Canada Elementary 18.00 11.70 7.26 50.07 200.00 20.00 20,400$ 5,000$ 19,980$ 7,500$ 10,000$ 62,900$ 8,200$ 2,000$ 1,500$ 9,700$ 2,100$ 15,300$ 23,500$ 14,100$

La Honda Elementary 12.00 7.80 4.84 33.38 200.00 10.00 18,900$ 5,000$ 7,980$ 1,850$ 10,000$ 43,800$ 5,700$ 2,000$ 1,500$ 3,100$ 1,400$ 8,000$ 13,700$ 9,400$

Lompoc Valley Middle School 8.00 5.20 3.23 22.25 200.00 10.00 18,900$ 5,000$ 19,440$ 7,200$ 10,000$ 60,600$ 7,900$ 2,000$ 1,500$ 3,100$ 1,000$ 7,600$ 15,500$ 6,300$

Miguelito Elementary 7.00 4.55 2.82 19.47 200.00 5.00 17,000$ 5,000$ 42,360$ 9,150$ 10,000$ 83,600$ 10,900$ 2,000$ 1,500$ 1,600$ 800$ 5,900$ 16,800$ 5,500$

Mission Valley School 3.35 2.18 1.35 9.33 200.00 5.00 17,000$ 5,000$ 5,100$ 13,350$ 10,000$ 50,500$ 6,600$ 2,000$ 1,500$ 1,600$ 400$ 5,500$ 12,100$ 2,700$

Lompoc High School 28.00 18.20 11.29 77.89 200.00 20.00 20,400$ 5,000$ 10,500$ 3,425$ 10,000$ 49,400$ 6,400$ 2,000$ 1,500$ 9,700$ 3,200$ 16,400$ 22,800$ 21,900$

Barton Park** 10.00 8.50 5.27 36.38 200.00 10.00 18,900$ 5,000$ 2,640$ 7,400$ 2,000$ 36,000$ 4,700$ 500$ 1,500$ 3,100$ 1,500$ 6,600$ 11,300$ 10,200$

Beattie Park 21.00 17.85 11.07 76.39 200.00 20.00 20,400$ 5,000$ 36,840$ 2,500$ 2,000$ 66,800$ 8,700$ 500$ 1,500$ 9,700$ 3,200$ 14,900$ 23,600$ 21,400$

Briar Creek Park 9.00 7.65 4.74 32.74 200.00 10.00 18,900$ 5,000$ 2,040$ 2,375$ 2,000$ 30,400$ 4,000$ 500$ 1,500$ 3,100$ 1,400$ 6,500$ 10,500$ 9,200$

Johns-Manville Park 10.00 8.50 5.27 36.38 200.00 10.00 18,900$ 5,000$ 3,720$ 7,950$ 2,000$ 37,600$ 4,900$ 500$ 1,500$ 3,100$ 1,500$ 6,600$ 11,500$ 10,200$

Ken Adam Park** 9.00 7.65 4.74 32.74 200.00 10.00 18,900$ 5,000$ 8,040$ 2,900$ 2,000$ 36,900$ 4,800$ 500$ 1,500$ 3,100$ 1,400$ 6,500$ 11,300$ 9,200$

Ryon Park 20.00 17.00 10.54 72.75 200.00 20.00 20,400$ 5,000$ 15,720$ 7,800$ 2,000$ 51,000$ 6,700$ 500$ 1,500$ 9,700$ 3,000$ 14,700$ 21,400$ 20,400$

Thompson Park** 5.00 4.25 2.64 18.19 200.00 5.00 17,000$ 5,000$ 7,800$ 750$ 2,000$ 32,600$ 4,300$ 500$ 1,500$ 1,600$ 800$ 4,400$ 8,700$ 5,100$

Westvale Park 2.15 1.83 1.13 7.82 200.00 5.00 17,000$ 5,000$ 12,300$ 1,000$ 2,000$ 37,300$ 4,900$ 500$ 1,500$ 1,600$ 400$ 4,000$ 8,900$ 2,200$

142.36 88.30 609.25 876,000$ 114,300$ 146,300$ 260,600$ 170,600$

*Centennial Park and College Park are not considered due to small irrigation demand.

*Well construction cost (include equipments) based on estimate from A & A Pump & Well Sevice.

*Assumed pipeline unit price : $60/LF

*Assumed power conduit unit price : $25/LF

Cost of treated water = $1,198/AFT

Assumed Interest Rate 5%

Amorization Period 10 years

Construction Cost O & M Cost

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