Presentation Transcript
Slide1: Household Water Systems
Household Water System Components: Household Water System Components Water Source (well, spring, pond, or cistern)
Pump
Pressure Tank
Pressure Switch
Check Valve
Piping
Optional Treatment Equipment
(Softener, Filter, Disinfection Unit, etc)
Slide3: Typical Shallow-Well Water System
PUMP POWER CONTROL BOX
SHALLOW-WELL JET PUMP CHECK VALVE WELL CASING SUCTION PIPE
SUPPLY PIPE TO HOUSE PRESSURE TANK
PRESSURE SWITCH
Water Pump Options: Water Pump Options
Slide5: Pump House with Shallow Well Pump PRESSURE SWITCH
Slide6: Jet Pump Installations Shallow-Well Jet Pump Deep-Well Jet Pump
(Two-Pipe System)
Slide7: Intake Pipe To Pressure Tank Pressure Pipe (Return Flow) Lift Pipe (Upward Flow)
Jet Ejector (Venturi) Nozzle Water Jet Pump Schematic Diagram
Increases practical suction lift by diverting part of the pump discharge to the ejector on the lift pipe
The greater the suction lift, the greater the percentage of discharge water must be diverted
Maximum practical lift is limited to approximately 200 feet by economics
Slide8: Deep-Well Jet Pump Ejector Units Two-Pipe System
Well Cap
Return Pipe
Lift Pipe
(w/ Venturi)
Nozzle
Foot Valve
Intake Strainer Packer System
Return Flow
Lift Pipe
(w/ Venturi)
Nozzle
Foot Valve
Packer
Suction Pipe
Slide9: Submersible Water Pumps
- Good for deep wells
High efficiency
Wells as small as 4” diameter
Slide10: Submersible Pump with Pitless Adapter FROST LINE
Slide11: Pressure Switch Controls water pump
Turns on when system pressure drops to 20 (30) psi
Turns off when system pressure rises to 40 (50) psi
Low pressure shut-down in case well water level drops
Pressure Tank: Pressure Tank Is not meant to provide household water storage
Delays pump turn-on and extends pump run time
Eliminates frequent, short On/Off cycles which can burn up the pump motor
Volume of pre-charged tank should be at least 6 times the delivery of the pump in 1 minute
Volume of uncharged tank should be at least 10 times the delivery of the pump in 1 minute
Slide13: Pressure Tank Typical uncharged pressure tank (no air bladder/diaphragm) installation Pipe Plug
(to be removed when system is drained to correct waterlogging) Pressure Switch Delivery Pipe from Pump Main Power Cutoff Switch
Slide14: Useable Storage Capacity of Pressure Tanks Over Normal Operating Range
(Not Pre-charged) 42 gallons 40 lbs
20 lbs Water Level at
12 gallons 82 gallons
Slide15: Examples of Pre-charged Pressure Tanks
Slide16: Effect of Waterlogging on Useable Pressure Tank Capacity
Slide17: Waterlogging To correct waterlogged pressure tanks:
-Turn off power to pump
Open a faucet to drain system
Remove pipe plug at top of tank to let air into tank and finish draining system
Replace pipe plug (use teflon tape or pipe compound to seal properly)
Close faucet
Turn on power
Repeat this process whenever the pump begins starting immediately every time a faucet is opened Pipe Plug
(to be removed when system is drained to correct waterlogging) Power Switch
Slide18: Controlling Waterlogging in Pressure Tanks
Slide19: Submersible Pump Check Valve Cutaway Water Flow
Household Water Requirement: Household Water Requirement Typical Usage: 50-100 gallons/person-day (drinking, bathing, laundry, toilet flushing, dishwashing, cooking, etc.)
Well Flow Rate Requirement:
Minimum Acceptable Rate: 5 gpm
Preferred Rate: 10 gpm
Minimum Fire Protection Rate: 20 gpm
Household Water Requirements: Household Water Requirements
Farmstead Water Requirement(Flow Rate): Farmstead Water Requirement (Flow Rate)
Intermediate Water Storage: Intermediate Water Storage Improves usability of low-yield wells
Well pump operates at low flow for extended periods (overnight) to fill storage tank
Pressure pump uses water from storage to supply immediate household demand
Minimum intermediate storage capacity should be at least equal to daily household water use (2-3 days’ storage capacity preferred)
Slide24: Intermediate Storage for Low-Yield Wells
Slide25: Intermediate Storage Tank
(filled by submersible well pump) Pressure Tank Pressure Pump Low Yield Well Water System Inlet from Well Pump Pressure Pump Suction Line Supply Line to House Check Valve
Water Treatment Equipment: Water Treatment Equipment Disinfection Equipment
Filters
Water Softeners
Water Disinfection Options-Bacteria & Viruses-: Water Disinfection Options -Bacteria & Viruses- Chlorination
Shock chlorination
Continuous chlorination
Dry pellet chlorinator
Chlorine solution feed pump
Chlorine solution venturi injector
Ozonation
Ultraviolet Irradiation
Shock Chlorination: Shock Chlorination Use laundry bleach (5.25%) w/ no additives
Pour 4 pints of bleach into well vent for each 100 gallons of water in system
Recirculate water into well for 20 minutes
Open all outlets until bleach is smelled
Let system stand idle overnight (4 hrs minimum)
Flush system
Re-test for bacteria after 10-14 days of use
Slide29: Dry Pellet Chlorinators -Electric powered (110 or 220 volt)
-Controlled by pump controller
Few moving parts
Uses calcium hypochlorite tablets
Treats water in the well
Longer Cl contact time
No solutions to mix
Treats up to 20 gpm
Slide30: Venturi Solution Injector Injects any liquid solution
Injection rate proportional to water flow rate
Adjustable over wide range of flow and injection rates
Slide31: Metering Pump Injects any type of solution
Controlled by water pump controller
Constant injection rate
Adjusts to wide range of flow and injection rates
Slide32:
SIGHT PORT Ultraviolet Disinfection Unit
Water Treatment Options- Iron or Manganese -: Water Treatment Options - Iron or Manganese - Shock Chlorination
Continuous Chlorination
Dry pellet chlorinator
Chlorine solution feed pump
Chlorine solution venturi injector
Ozonation
Oxidizing (Greensand) Filter
Ion Exchange Water Softener
Iron Treatment Options: Iron Treatment Options
Water Treatment Options-Corrosion-: Water Treatment Options -Corrosion- Neutralizing Filter
Limestone chips
Marble chips
Caustic Soda (NaOH) Feeder
metering pump or venturi injector
Soda Ash (Na2CO3) Feeder
Metering pump or venturi injector
Water Treatment Options-Hydrogen Sulfide (H2S) “Rotten Egg” Odor-: Water Treatment Options -Hydrogen Sulfide (H2S) “Rotten Egg” Odor- Activated Carbon Filter
Oxidizing Filter
Shock Chlorination
Continuous Chlorination
Dry pellet chlorinator
Chlorine solution metering pump
Chlorine solution venturi injector
Ozonation
TDS/Mineral Treatment: TDS/Mineral Treatment Reverse Osmosis
Distillation
Slide39: 4-stage Reverse Osmosis Unit with Tank and Faucet
Reverse Osmosis Systems: Reverse Osmosis Systems Reduce mineral concentrations by 90%
15 gallon/day under-sink units: $150-$300
Require pre-softening with hard water
Operate on water system pressure (40 psi)
Wastewater:Treated water ratio 4 or 5:1
Membranes: $70-100 each; 5 year life
Slide41: Distillation Unit Heating Element Vaporization Chamber Condensing Coil Gas Vent Raw Water Inlet Distilled Water Rising Steam Drain
Slide42: Countertop Distillers initial cost $150-$1000
4-8 hours/gallon treatment rate
2.75-3.0 kWh/gallon energy consumption
removes 99.9% of all contaminants
electric co-ops often subsidize purchase
Carbon Filters: Carbon Filters Remove contaminants by adsorption on carbon particle surface
Hierarchy of contaminant adsorption
Saturated filters can actually increase concentration of some contaminants
Not effective on nitrate, hardness or bacteria
Filter cold water only
Bigger is better - more surface area
Slide44: Cartridge Filters Filter Wrench Filter Housing Carbon Cartridge (taste, odor, chlorine, organics)
Particle Cartridge (sand, sediment)
Ion Exchange Water Softeners: Ion Exchange Water Softeners Exchange sodium ions for calcium and magnesium ions in water
Increase EC somewhat
May be dietary hazard - hypertension (adds 140 mg/l of sodium in “Hard” water)
Use potassium salt (KCl) for health reasons
Slide46: Ion exchange softeners replace Ca++ and Mg++ with Na+ ions.
Zeolite medium is recharged with Na+ by NaCl brine when depleted.
Slide47: Ion Exchange Water Softener with Sensor- Controlled Recharge
Softener Selection Considerations: Softener Selection Considerations Required grain capacity
Daily water use (household population)
Water hardness
Desired regeneration schedule
Initial cost
Water conservation
Other (Iron removal, etc.)
Ion Exchange Water Softener Capacity: Ion Exchange Water Softener Capacity Rated by grains of hardness treated between regenerations
1 grain/gallon (gpg) = 17.1 mg/l
Example:
Water hardness = 200 mg/l = 200/17.1 = 11.7 gpg
Softener Capacity = 30,000 grains
Household Population = 4 persons
Calculate:
Water Use = 4 persons x 50gal./person-day = 200 gal./day
Daily Hardness Treated = 200 gpd x 11.7 gpg = 2339 grains/day
Regeneration Interval = 30,000 grains/ 2339 grains/day = 12.8 days
Recommended Softener Sizes: Recommended Softener Sizes
Ion Exchange Water Softener Recharge Control Method: Ion Exchange Water Softener Recharge Control Method
-Time Clock
-Flow Meter
-Hardness Sensor Water Use
+ -
Initial Cost
- +
Slide52: Typical Programmable Water Softener Controller
Water Softening: Water Softening Permanent magnet water softeners don’t work
Electrostatic and catalytic descalers may “descale” water, but don’t soften it
Scale will not buildup on pipes, water heater elements, bathtubs etc.
Sudsing action of soaps is not improved
Slide54: Private Water System Resources