Please fill all required fields
Osa Mountain Village Phase 1              
Potable Water System Design  
Peak Design Flow
Plumbing Fixtures
Units Qty Lav WC Kit Sink Shower HB Washer
1 Bath Units
2 Bath Units
Community Center
Individual Lots
Fixture Totals
WSFU Total
Fixture Units Total WSFU
Peak Flow GPM (Does not include swimming pool.)
Peak Flow F3/Sec
Pipe Size Inch (Distribution from storage tank. Sized to handle peak.)
Velocity (Max 6-8 FPS) FPS (Recommended Max = 6-8 FPS.)
Average Daily Flow
Dwelling Units Qty People % Occ
1 Br 1 Bath Units
2 Br 2 Bath Units
Individual Lots
Total Number of People: Each
Avg Daily Use Per Capita: GPCPD
Community Center/Bar
GPD (Incl public toilets, kitchen sinks, laundry)
Swimming Pool
GPD (makeup for evaporation, washing decks, etc)
Total Daily Demand
Gal (Including swimming pool water)
Safety Factor:
Total Demand w/ Safety:
Gal (Existing Storage tank ~ 5,800 Gallons)
Continuous Flow Rate (24 hr) GPM
Peak Flow
Minimum Pipe Size
Inch (From Stream Intake to Treatment Plant.)
Velocity (Max 6-8 FPS)
FPS (Recommended Max = 6-8 FPS.)
Sedimentation Tank Design Metric English
Total Daily Demand M3/Day GPD Includes Swimming Pool
Flow Rate (Total/24 Hr) M3/Hr GPH Daily Demand / 24 Hr
Particle Settling Velocity M/Hr
(Select value from table below)
Required Surface Area M2 SF
Tank Width M Inches
Tank Length M Inches
Surface Area M2 SF
Tank Depth M Inches
Volume M3 Ft3
Total filter media volume including gravel bed over underdrain blocks
Intake Structure Detail   Outlet Detail
Slow Sand Filter Design Metric English Comments
Total Daily Demand M3/Day GPD From Phase 1 Demand Worksheet (not incl swimming pool)
Hourly Flow Rate M3/Hr GPH Daily Demand / 24 Hr
Surface Loading Rate M3/Hr/M2 G/Hr/SF Recommended Rate = 0.1 - 0.4 M3/M2/Hr
Required Surface Area M2 SF Hourly flow / Surface loading rate
Tank Width M Inches
Tank Length M Inches
Number of Tanks EA EA
Total Surface Area M2 SF (Total of all MSSF tanks. Must exceed Required sfc area)
Tank Depth M Inches (sum of following items…)
Underdrain M Inches 15x20x40 cm blocks laid 1 cm apart.
Filter Bed (0.3 - 0.8M) M Inches Recommended depth, not incl underdrain, between 0.3 to 0.8 meters
Max Water over Filter Media M Inches
Freeboard M Inches Distance from top of tank to normal overflow level.
Sand Volume M3 Ft3 Total filter media volume including gravel bed over underdrain CMU
Elevation Of OF/Fill Pipe AFF
Inches Min Water level above media, established by OF/fill pipe level (5 cm)
Total Water Volume (to Weir) M3 Gallons Volume of water to overflow weir level (NI media)
Tank Volume (Incl freeboard) M3 Gallons Volume of water to top of tank (NI media)
Backwash Flow rate / M2 Surface 1.00 L/S/M2 GPM/M2
Pump Flow Rate L/S GPM
Pressure Drop
Pipe Size
Pump Efficiency
Pump Size
Design Notes
Flow rate through the filter bed is controlled using valves or weirs with adjustable height.
Filter media: crushed and washed quartzite or similar materials. It is important that the filter media not have particles made of soft shale or mud stones high in oxidized metals. Particle size between 0.15 and 0.35 mm, uniformity coefficient < 2  
The wastewater produced during the backwash process is removed, after allowing the finest media to settle (about 30 seconds), using perforated pipes located along and attached to the interior walls of the filter. The holes in the pipe are slightly downward facing to avoid capturing any of the fluidized media and are located approximately five centimetres above the surface of the media (all of the water is not removed).  
An air-vacuum control valve attached to the top of the outlet standpipe ensures that the filter produces treated water with the outlet under atmospheric pressure and backwashes under full backwash pump pressure.  
The perforated pipes are attached to a siphon spillway system that also acts as an emergency overflow system. The rate of flow through this system is controlled by a dedicated waste water flow control valve (not greater than the capacity to take the wastewater to disposal). A second, waste water operations valve is used to alternatively prevent flow from the filter until backwash is completed and then opened to facilitate the siphon evacuation process. The same valve is left open after backwash is completed to provide emergency overflow protection.  
Description (Wilberth) (Translation) Qty Unit Price Cost Comments, Questions  
Mallas Electro Soldadas WWF EA what unit of measure?
Blocks CMU 15x20x40 (6" x 8' x 16") EA
Varillas De 3/8 Rebar # 3 EA what is length?
Alhambre Negro Tie Wire (black) Kg
Disco De Corte Rapido para metal Metal Cutting Saw Blades, 7" EA
Base Gravel? Mortar mix? MT
sacos de cemento Sacks Of Cement EA
Hidromax Hidromax (Concrete Additive, Impermeable) Gal
reglas 1x3 en 3 varas 1x3 Studs(?) for formwork framing? EA
formaletas de 12" en 3 varas formwork boards? EA
Clavos, 4" Nails, 4" Kg
Clavos, 2-1/2" Nails, 2-1/2" Kg
Clavos, 2" Nails, 2" Kg
Clavos, 1-1/2" Nails, 1-1/2" Kg
Clavos, 1" Nails, 1" Kg
Rollo De Cuerda Nilon Nylon Cord Roll
Disco Para Patin De 7' Calsado Saw blade, 7" EA
Impermeabilisante Blanco Waterproofing coating, white Sacks
Poste Electrico Con Caja Y Medidor meter base and pedestal -- NOT REQUIRED
Not necessary if run wire up from meter at water tank. Distance info from Warner
Varillas De Copper ground rods EA
Cable #6 3 Colores Boxes of #6 cable (what is length?) EA Depends on info from Warner
Breakers circuit breakers (Qty & size to be determined)
(1) 1 HP pump, 240V, (4) ext lighting, (1) ctrls, (2) outlets
Tubos Conduit De 1-1/4" Conduit (LF & size to be determined) EA Depends on info from Warner and elec loads calc'ed
Cajas Cuadradas J-Boxes, square EA To be determined
Cajas Rectangulares Outlet Boxes, Rectangular EA To be determined
Tomas Para Exteriores Dobles Outlets, Duplex, GFI In WP Box EA To be determined
Apagador Para Exteriores Dobles Switch, Wp Box EA To be determined
Rollo Tape 3M Electrico Submersible Roll Electrical Tape EA To be determined
Uniones Conduit de 1-1/4" Couplings, 1-1/4" EA To be determined
Curvas Conduit de 1-1/4" Long Sweep Elbows EA To be determined
vave de chorro R.P. 1/2 1/2" valve???? EA To be determined
tuvos de pvc de alta 1/2" PVC sched 40? EA To be determined
tuvos de pvc de don't know why twice
To be determined
everything else on the list is too soon