- 2.3 Storage Design Water Supply Systems
- Home Water Storage Systems
- Residential Water Storage System Design
- 2.3 Storage Design Water Supply System
Every shelter-in-place supply should have water storage. A small word of caution: Don’t try to go cheap on your water storage. Buy a food grade water storage container like a 55, 30 or 5 gallon container and use that. Don’t fill up your old juice bottles or your old milk jugs. Each system shall be identified with a colored pipe or band and coded with paints, wraps, and materials compatible with the piping. Except as required by Section 601.3.3, nonpotable water systems shall have a yellow background with black uppercase lettering, with the words 'CAUTION: NONPOTABLE WATER, DO NOT DRINK.'
DFU are used to determine the drainage from fixtures and required capacity of sewer service systems
DFU (Drainage Fixture Unit Values) is defined by the the Uniform Plumbing Code (UPC) and can be used to determine required drainage capacities from fixtures and their service systems.
A Fixture Unit is not a flow rate unit but a design factor based on the rate of discharge, time of operation and frequency of use of a fixture. A fixture unit is equal to one cubic foot of water drained in an 1 1/4 pipe over one minute (≈ 7.48 US gpm, ≈ 0.47 l/s).
| Individual Appliance, Appurtenance or Fixture | Minimum Size of Trap | Drainage Fixture Unit Values (DFU) | Typical Values used in Europe | |
|---|---|---|---|---|
| (inch) | Private Installations | Public Installations | (l/s) | |
| Automatic clothes washers, commercial | 2 | 3 | ||
| Automatic clothes washers, residential | 2 | 2 | ||
| Bathroom (water closet, lavatory, bidet and tub or shower) | 3 | 6 | - | |
| Bathtub | 1 1/2 | 2 | 2 | 0.9 |
| Bidet | 1 1/4 | 1 | 0.3 | |
| Bidet | 1 1/2 | 2 | ||
| Clothes Washer | 2 | 3 | 3 | |
| Dental unit, cuspidor | 1 1/4 | 1 | ||
| Dental lavatory | 1 1/2 | 1 | ||
| Dishwashing machine, domestic | 1 1/2 | 2 | 2 | 0.6 |
| Drinking fountain | 1 1/4 | 0.5 | 0.5 | 0.1 |
| Floor drain, 3' | 3 | 6 | 6 | |
| Floor drain, 4' | 4 | 8 | 8 | 2 |
| Food waste disposer | 2 | 3 | ||
| Shower | 2 | 2 | 2 | 0.4 |
| Laundry tub | 1 1/2 | 2 | 2 | |
| Lavatory | 1 1/4 | 1 | 1 | |
| Bar sink | 1 1/2 | 1 | ||
| Kitchen sink, domestic | 1 1/2 | 2 | 2 | |
| Laundry sink | 1 1/2 | 2 | 2 | |
| Mobile home, trap | 3 | 12 | ||
| Service or mop basin | 2 | 3 | ||
| Sink, bar | 1 1/2 | 1 | 0.3 | |
| Sink, clinical | 1 1/2 | 2 | ||
| Sink, commercial with food waste | 2 | 3 | ||
| Sink, kitchen domestic | 1 1/2 | 2 | 2 | 0.6 |
| Sink, laundry | 1 1/2 | 2 | 2 | |
| Sink, service mop basin | 2 | 3 | 0.9 | |
| Urinal | 2 | 2 | 2 | 0.3 |
| Washfountain | 1 1/2 | 2 | ||
| WC - Water Closet, gravity tank | 3 | 3 | 4 | 1.8 |
| WC - Water Closet, flushometer tank, valve | 3 | 3 | 4 | |
| Water cooler | 1 1/4 | 0.5 | 0.5 | |
Fixture Units are used in plumbing design for both water supply (WFSU) and waste water (DFU).
- Water Supply Fixture Unit - WFSU
Since the fixtures in a system are never used all at the same time, the total units (capacity) achieved by adding the numbers for all fixtures must be compensated for intermittent use if we want a realistic estimate of the total drainage load.
Related Topics
- Sanitary Drainage Systems - The purpose of a sanitary drainage system is to remove effluent discharged from plumbing fixtures and other equipment
Related Documents
- Capacity of Sewer Pipes - Carrying capacity of sewer and wastewater pipes - gpm and liter per second
- Cast Iron Soil Pipes - Dimensions - Dimensions of cast iron soil pipes
- Cleanouts in Draining Systems - Cleanouts provides access to the sewer for rodding
- Cold Water Storage Capacity - Required cold water storage capacity - commonly used fixtures and types of buildings
- Cold Water Storage per Occupant - Cold water storage for occupants in common types of buildings as factories, hospitals, houses and more
- Drainage Fixtures - Unit Loads and Sanitary Piping - Maximum Drainage Fixture Unit - DFU - loads for sanitary piping
- Drains and Sewers - Drainage Fixture Units (DFU) connected to building drains and sewers
- Fixture Units and Required Trap Size - No. of fixture units and required trap sizes
- Fixtures and Trap Sizes - Recommended drain trap sizes for different types of fixtures
- Main Vents in Draining Systems - Vents in draining systems protects traps against pressure differences that could cause them to siphon or blow out
- Plumbing Codes - Plumbing or sanitation codes are a set of rules and regulations imposed by cities, counties or states
- Volume Flow in Sanitary Drainage Systems - Calculate expected load in sanitary drainage systems
- Water Supply - Fixture Units WSFU - WSFU is used to calculate water supply service systems
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Surface water and groundwater are both important sources for communitywater supply needs. Groundwater is a common source for single homes and small towns, and rivers and lakes are the usual sources for large cities. Although approximately 98 percent of liquid fresh water exists as groundwater, much of it occurs very deep. This makes pumping very expensive, preventing the full development and use of all groundwater resources.
The hydrologic cycle
2.3 Storage Design Water Supply Systems
Water is in constant circulation, powered by the energy from sunlight and gravity in a natural process called the hydrologic cycle. Water evaporates from the ocean and land surfaces, is held temporarily as vapour in the atmosphere, and falls back to Earth’s surface as precipitation. Surface water is the residue of precipitation and melted snow, called runoff. Where the average rate of precipitation exceeds the rate at which runoff seeps into the soil, evaporates, or is absorbed by vegetation, bodies of surface water such as streams, rivers, and lakes are formed. Water that infiltrates Earth’s surface becomes groundwater, slowly seeping downward into extensive layers of porous soil and rock called aquifers. Under the pull of gravity, groundwater flows slowly and steadily through the aquifer. In low areas it emerges in springs and streams. Both surface water and groundwater eventually return to the ocean, where evaporation replenishes the supply of atmospheric water vapour. Winds carry the moist air over land, precipitation occurs, and the hydrologic cycle continues.
Surface water sources
The total land area that contributes surface runoff to a river or lake is called a watershed, drainage basin, or catchment area. The volume of water available for municipal supply depends mostly on the amount of rainfall. It also depends on the size of the watershed, the slope of the ground, the type of soil and vegetation, and the type of land use.
Home Water Storage Systems
The flow rate or discharge of a river varies with time. Higher flow rates typically occur in the spring, and lower flow rates occur in the winter, though this is often not the case in areas with monsoon systems. When the average discharge of a river is not enough for a dependable supply of water, a conservation reservoir may be built. The flow of water is blocked by a dam, allowing an artificial lake to be formed. Conservation reservoirs store water from wet weather periods for use during times of drought and low streamflow. A water intake structure is built within the reservoir, with inlet ports and valves at several depths. Since the quality of water in a reservoir varies seasonally with depth, a multilevel intake allows water of best quality to be withdrawn. Sometimes it is advisable, for economic reasons, to provide a multipurpose reservoir. A multipurpose reservoir is designed to satisfy a combination of community water needs. In addition to drinking water, the reservoir may also provide flood control, hydroelectric power, and recreation.
Residential Water Storage System Design
Groundwater sources
2.3 Storage Design Water Supply System
The value of an aquifer as a source of groundwater is a function of the porosity of the geologic stratum, or layer, of which it is formed. Water is withdrawn from an aquifer by pumping it out of a well or infiltration gallery. An infiltration gallery typically includes several horizontal perforated pipes radiating outward from the bottom of a large-diameter vertical shaft. Wells are constructed in several ways, depending on the depth and nature of the aquifer. Wells used for public water supplies, usually more than 30 metres (100 feet) deep and from 10 to 30 cm (4 to 12 inches) in diameter, must penetrate large aquifers that can provide dependable yields of good-quality water. They are drilled using impact or rotary techniques and are usually lined with a metal pipe or casing to prevent contamination. The annular space around the outside of the upper portion of the casing is filled with cement grout, and a special sanitary seal is installed at the top to provide further protection. At the bottom of the casing, a slotted screen is attached to strain silt and sand out of the groundwater. A submersible pump driven by an electric motor can be used to raise the water to the surface. Sometimes a deep well may penetrate a confined artesian aquifer, in which case natural hydrostatic pressure can raise the water to the surface.