Types Of Springs
Non-seepage springs, also described as "concentrated" springs, and low area springs are the most common springs used as drinking water.
- Non-seepage or Concentrated springs are usually located at the base of mountains or hillsides and can be easily developed. Surface water drains away from this type of spring which makes it easier to protect from contaminants.
- Low-area springs are found in valleys and low-lying areas. The development of low-area springs requires more care because of the increased potential for contamination from surface water.
- Seepage springs are the most difficult to develop. They are easily contaminated because groundwater is collected over a wide area from sources that may be very close to the surface. During periods of drought, seepage springs may dry up completely.
Is A Spring Box Necessary?
Many publications describe the protection of springs from contamination using spring boxes. However, in many cases a spring box may not really be necessary. Protecting a spring without using a spring box assumes a gravity spring with a flow rate of up to about 10 gallons(or 35 liters)/minute.
Use of the design with higher flow rates is possible in some instances, but more than one delivery pipe and a larger concreted hollow or "sump" behind the headwall are recommended for such flows.
In a technical brief from the collection Running Water(Shaw, 1999), spring boxes are described, and an alternative design is presented.
An alternative to building a spring box can be used if water can be protected and collected without a spring box, if no sedimentation is needed, and if no storage box is required. The technical brief describes the essential parts to protecting a spring without a spring box, including site selection, excavation, construction of the headwall, and is a valuable resource addressing all types of off grid, water related projects.
The approach is a way to protect the spring as it naturally flows, accounting for shifts in geology through time and capturing the full amount of water, while using the most practical amount of materials. There is no specialized skill involved with the construction of these spring captures.
Advantages Of Protecting A Spring Without The Use Of A Spring Box:
1. Simpler design
2. Quicker construction
3. Suits flatter sites
4. Reduced cost
5. No provision is needed for the depth of the storage/sedimentation chamber
A Spring Box Can Be Useful As:
1. A sedimentation chamber where particles of sand carried in the spring water can settle out. However, spring flows tend to carry little sediment material, and generally do not require a large collection tank for sedimentation purposes. Any sediment that may be present is primarily settled out or filtered in the spring.
2. A storage chamber which is useful for springs where the demand for water exceeds the flow rate of the spring.
3. A method of protecting the spring water from contamination.
4. A way of collecting the spring water by giving it an easy
flow path from the aquifer into a delivery pipe.
Determine Whether Or Not To Use A Spring Box
You might want to consider foregoing a spring box altogether if...
1. Water from a spring can be protected and collected without a spring box,
2. and if no sedimentation is needed because the water carries only a low level of suspended solids,
3. and if no storage is needed because the spring flows at a rate sufficient to meet the peak demand...
then no spring box is required.
What Characteristics Should A Spring Box Have
For maximum protection against contamination, a properly developed spring should have the following characteristics:
- The size of a spring box depends on the amount of storage required. Ideally the box should be at least 4 feet deep and should extend at least 1 foot above the ground. The median size of a spring box is 4' x 3' x 3' and 60 square feet of improved, protected area. This size will accommodate most springs.
- absence of contamination sources
- a collection system to concentrate and channel the flow (e.g., a cutoff wall or a system of perforated pipe located where the water is at least 3 feet below the surface)
- additional storage tank and disinfection equipment, if necessary
- A properly constructed spring box will have a watertight cover that fits like a shoe box lid. This will prevent insects, animals, and surface water from entering the spring.
- A spring box should not contain silt or animals(I should hope not! lol)
- the space behind the box should be sealed with puddled clay or concrete plinth(slab).
- You will typically want to have 4 pipes on your spring box. These are:
1. The inlet pipe - where the water enters the spring box
2. The exit pipe - where your water leaves the spring box and goes to: either another containment tank(usually necessary if you have a low flow rate and need access to a larger volume of water than the spring catchment provides at any given time), or, straight to your spigot.
3. A washout pipe - This is simply a pipe installed in or near the base of the box that can easily be opened so that sediment and trash can be flushed out.
4. An overflow or vent pipe. This pipe is installed on or near the top of the spring box, and run away from the area. If your flow rate exceeds the spring box's capacity, the excess water needs somewhere to go. Remember that if you block a springs flow, it can completely divert it's emergence from the ground to somewhere inaccessible. The end of your vent pipe should be covered by a screen to prevent critters and other things from getting into the spring box from the outside.