Presentation on theme: "Las Delicias, El Salvador Water Supply Project Implementation Proposal Phase I Trip Dates: May 2012 Presented to TAC: March 6, 2012."— Presentation transcript:
Las Delicias, El Salvador Water Supply Project Implementation Proposal Phase I Trip Dates: May 2012 Presented to TAC: March 6, 2012
Presentation Outline Overview of Las Delicias Community Current Water Supply System and Challenges Proposed Improvement to Water System – Summary of alternative analysis – Phase I (May 2012) New Water Tank at Intermediate Elevation New Supply pipeline and distribution pipeline – Phase II (Fall 2012) New pump (or VFD) Improvements to distribution system Control system improvements and pumping at night Logistics and Implementation
Las Delicias, El Salvador Community Facts – ~600 homes, 2700 residents – 15 miles NW of San Salvador – On Western Slopes of Volcan San Salvador – Homes Spread Out, but Las Delicias is Bordered by Several Similar Communities – Water Storage & Piping System installed 20 years ago With Water Delivery by Truck – Well and Pump Installed < 5 years ago – Residents are Poor (<$10/week income) – Community Well-Organized through Adesco and NGOs (FIAT & FIMRC) – Able to spend about $5 per household on water each month Project History Project FIAT and FIMRC have been active in Las Delicias for > 5 years Initial Contact with Project FIAT (Dave H.) January 2009 Application to EWB-USA March 2009 Project Approved May 2009 Preliminary Assessment Visit July 2009 First Assessment Trip July 2010 Second Assessment Trip November 2011
Challenges to Las Delicias Water Supply System High electric cost – Typical ADESCO revenue from water fee ~$2300/mo – Typical monthly cost for water system ~$2000/mo (mostly electicity ~$1500/mo) – Pumps run about 26 hr/wk – Not taking advantage of nightime off-peak rates – Power factor on pumps leads to monthly fine of $50/month. Inequitable water distribution – Some homes report receiving water <1x/week and low flowrates – Valvulero controls distribution via valves to zones (Tramo) throughout community – Large number of new homes at low elevation Culture of scarcity where residents hoard water when it is flowing Water Quality: – Effectiveness of in-line chlorination is not clear
Electric Bill Monthly Income for Las Delicias ADESCO Water System Expenses
Alternatives Analysis Summary Drilling another well ($3500 for hydrogeological study) We spoke with a hydrologist in country and drilling a new well at higher elevation is considered to have low probability for success. Solar power for pump (eliminated due to high cost >$50K) Additional tank locations (three considered – current location on public land and co-located with current tank) Other locations require land purchase which could be costly and time consuming. VFD (variable frequency drive – possibility but must consider approx. 10% loss in pump efficiency at lower head) New pump for better efficiency at lower head.
Proposed Updates to Las Delicias Water System Objectives – Utilize existing and new tank at intermediate elevation to supply water to lower half of Las Delicias with lower pumping head required. – With new pump (or VFD on existing) and supply line reduced electricity costs due to lower head will result in more water for the community. – Improved distribution system more equitable water supply to all homes (especially at lower elevations) Phase I (May 2012) – New Water Tank at Intermediate Elevation – New Supply pipeline and distribution pipeline Phase II (Fall 2012) – New pump (or VFD added to existing) – Improvements to distribution piping system – Improving power factor for pump via capacitors to eliminate penalty. – Enabling pumping during nighttime to take advantage of lower rates by adding a timer circuit to the pump controller. (approx. 20% savings)
117 Homes Served by Tanque 3 33 Homes Served by Tanque 2 154 Homes Served by Tanque 1 Proposed Water Distribution System 280 Homes Served by New Tank DOWNHILL
Summary of potential changes in water distribution system CURRENT SYSTEM Storage – Tanque 1: 35,000 gal – Tanque 2: 11,000 gal – Tanque 3: 25,000 gal Pump supplies water to Tanques 1 & 3 at 175 gpm, ~4 days per week Spring supplies water to Tanque 2 (and other tanques) Homes serviced by Tanques 1.291 2.33 3.260 PROPOSED MODIFICATION Storage – Tanque 1: 35,000 gal – Tanque 2: 11,000 gal – Tanque 3: 25,000 gal – New Tank (combination): 28,600 gal Current 65 HP Pump supplies water to Tanques 1 & 3 at 175 gpm New 20 HP pump will supplywater to new tank at 175 gpm with much lower head and energy savings. Homes serviced by Tanques 1.154 2.33 3.117 New: 280 New tank reduces demand of water from Tanques 1&2 (which require high head) by roughly 50%
Map of Current Water System (section relevant for EWB-MAP modifications) RED lines – supply lines to tank (uphill by pump) BLUE lines – distributions lines by gravity DOWNHILL Exisiting 11,000 gallon tank
Proposed update to Water System (section relevant for EWB-MAP modifications) RED lines – supply lines to tank (uphill by pump) BLUE lines – distributions lines by gravity NEW SUPPLY LINE 1 NEW DISTRIBUTION LINE 2c NEW DISTRIBUTION LINE 2a NEW DISTRIBUTION LINE 2b NEW TANK A B C D E F DOWNHILL
New Tank Design – Location and Coupling with Old Tank
Design of New Tank – 3D view of Block/Rebar construction
Tank Design response to J. Knight concerns Concrete block vs poured concrete. Block recommended by local Structural Engineer (Daniel Rivera). Assumed strength of concrete (2000-3000 psi acceptable – steel strength controls) Local Engineer accepted 3000 psi concrete although 2000 psi concrete will work as well. Tank seal at base of wall – We will look into this in further detail and will add it if necessary. We will contact seal manufacturer and seek advice of a water engineer before making a decision. Supply pipes will be connected to both tanks with shutoff valve to each.
Proposed update to Water System (section relevant for EWB-MAP modifications) RED lines – supply lines to tank (uphill by pump) BLUE lines – distributions lines by gravity NEW SUPPLY LINE 1 NEW DISTRIBUTION LINE 2c NEW DISTRIBUTION LINE 2a NEW DISTRIBUTION LINE 2b NEW TANK A B C D E F DOWNHILL Design of Additional Pipelines for - supplying water to tank - distributing water
A B C 105 m 240 m D 638 m 640 m 643 m 651 m Elevation: 640 m 655 m Supply Pipe 1 Pipe Profile NEW TANK Tee connect to 6 pipe Gate Valve 45° Elbow 90° Elbow with anchor Gate Valve 90° Elbow Pipe Exit PIPE FITTINGS Tee with Manual Air release valve Tee with Manual drain valve Road Crossing
Estimate of head losses in supply pipe 1 (smooth PVC) 4 PVC sufficient to keep major and minor losses to <10% of the elevation change
Supply Pipe 1 Trenching Based on recommendations from EWB Water Resource Guidelines and advice from Tony Sauder: – 70 cm trench depth (45 cm depth acceptable except in road crossing) with pipe buried below 50 cm – 10 cm bedding (2-12 mm soil) if stones/rocks present in trench – Back-fill with soil that is free of lumps, from stones (>3 cm), and from organic matter – PVC pipe joined in trench and cure for >10 hr prior to pressurizing. Keep joints exposed to check for leaks. Expansion joints not necessary – For road crossing, may bury PVC pipe inside steel or concrete pipe (ID > diameter of PVC joints); final decision to be made in the field after evaluating potential for erosion 70 cm trench depth 10 cm bedding 10 cm 50 cm
Valve Boxes Design options – Obtain pre-cast valve boxes with lockable lids locally – Build from bricks and mortar with metal lids Specifications – 4 Pipe centered about 55 cm below ground level – Box should extend 10 cm above ground level – Internal dimensions roughly 45cmx45cm – Place support under valve Photos of current valve boxes installed in Las Delicias
Valve Box Design Drawing of valve boxes to be constructed at Las Delicias
Thrust Anchors for Elbows &Tees From Russ Turner, Tetratech
Summary of May 2012 Implementation Keys to Success: Success assured by working closely with: – Local community providing excavating equipment, funds, land and labor. – Local Rotary Club and Structural Engineer Daniel Rivera providing funds, logistics and expertise. – NGO – Project FIAT helping with funds, logistics and volunteers as well as arranging for a cement mixer. FIAT has vast experience doing these types of projects in El Salvador. – The Honorary Consul of El Salvador in Philadelphia is working with one of our members (Paolo) to help coordinate the project with the local Mayors office. She has also informed us that she will arrange to allow us to ship components (such as pumps) to the country tax and duty free. – NGO - FIMRC providing local health related services to the community and EWB by helping us define objectives and measure results.
Summary of Finances for Implementation Local community provides excavation equipment, land, material transportation and field labor (assume avg. 4 people, 8 hrs/day for duration of project) Chapter currently has about $28,500 available for this project including. – $15,000 Rotary Grant (must be used by September – specifically ear- marked for tank) – $8,000 from Project FIAT – $5,500 in chapter funds Costs are estimated at about $27,000 including: – Tank estimate - $12,500 – Piping estimate - $10,500 – Transportation estimate $4,000 – We plan to raise additional funds to cover gap costs between now and May. We will delay piping if funds prohibit completion until the Fall.
Logistics and Implementation Plan Engineer – Daniel Rivera of Local Rotary in San Salvador will coordinate with local government, obtain building permit, help organize material delivery and oversee installation through periodic visits. Project FIAT volunteers will coordinate with local community, organize material deliveries, hire an albañil, provide secure space for materials, provide cement mixer, supply working volunteers and provide lodging and transportation for EWB volunteers. Local community will provide land, excavating equipment and labor as well as help in transporting materials to site. EWB volunteers will provide supervision, project management and labor. EWB volunteers will cover entire 5 week installation.
Contingency Plans (worst case scenarios) for Implementation Project can proceed even if EWB members are not present every day. Control runoff and use tarps if heavy rains become problematic.
Material Procurement Project Fiat has executed many similar projects. They know exactly where the type of materials used on this project can be obtained locally. Project FIAT will provide a locked building close to the tank site where materials can be securely stored. All material will be sourced locally. All materials are common everyday building materials. Daniel Rivera has reviewed the material list and did not have any issues with our selections. (He did recommend using grade 40 rebar instead of 60 and we followed his recommendation) The area near the village includes heavy industry and business enterprise and the community is only 15 miles from a major city. We foresee no major issues sourcing materials.
Plans for Phase II Implementation (Fall 2012) Install new pump (or VFD) Install Power Factor Correction Capacitors Install Timer Circuit to allow Night time Operation Install additional distribution pipes.
Metrics Increase water supply by ~40% without increasing operating cost Increase in % of homes receiving sufficient water (at least 2x per week)
Concluding Remarks Project is sustainable through community involvement and use of: – Locally available materials – Standard construction techniques typical to the area. – Adding to existing water system infrastructure using identical technologies. O&M will be the same as they are doing now. – The community already has people in place to operate and maintain the water system. Community will benefit through better distribution and more abundant supply with no increase in operating cost.