A Faircloth Skimmer® is a surface drain that floats on top of the water in a sediment basin. The skimmer inlet controls the rate of out flow and rises and falls as the basin fills and drains. It releases the cleanest water in the basin from near the surface. A skimmer is used instead of the rock and perforated riser outlets in sediment traps and basins.
The purpose of a sediment trap or basin is to capture muddy water and allow the sediment to settle to the bottom. The old methods drain the basin from the bottom, releasing the muddiest water in the basin. The skimmer is a surface drain that releases the cleanest water (although often still turbid) in the basin near the surface.
The Faircloth Skimmer® also controls the filling of the basin since just a trickle of water goes out during filling, thereby capturing most of the initial runoff to fill the pond and creating conditions where settling will occur. Then it drains the basin at a uniform rate in the required time, which other outlets don’t do and can’t do because of their variable heads.
Using a pump or a siphon with a floating inlet would drain the basin from near the surface but these methods are not automatic and have to be manually started after each rainfall. A flashboard riser would also drain from near the surface but must be manually operated.
No, not necessarily! A surface drain will not make a hole in the ground an efficient basin. Many
other factors are involved.
NO! Definitely not! The skimmer only drains the basin from the crest of the overflow down to the bottom. Its flow capacity to is too small to handle overflow so a spillway or riser or both are needed.
The size of the Faircloth Skimmer®, a 3” skimmer or a 4” skimmer for example, refers to the maximum size of the water inlet pipe. It does not refer to the pipe size used for the float or the barrel (or “arm” as some refer to it).
It is a simple process to choose the skimmer. You need to know the volume of the sediment basin in cubic feet and the number of days to drain the basin.
Then, use our online calculator to calculate the correct skimmer size. Choose the smallest size that will drain the basin’s volume in the required time. It may be necessary to reduce the flow rate further with a smaller orifice or hole in the inlet using the plug and adjustable cutter provided. The orifice size is calculated using the online calculator.
Call us at (919) 732-1244 or contact us if you have questions or need help.
Yes. The inlet size can be reduced using the plug and adjustable cutter included to reduce the flow through the skimmer and “customize” the flow rate for the volume of the basin the skimmer is to be used in.
NO! These charts do not take into account the variation in the head (the depth of the inlet under water) of the different sizes of our skimmers. Use our flow charts and calculators.
It is smaller to reduce buoyancy when the pipe is less than full. This buoyancy would tend to lift the inlet causing it to float upward and could reduce flow through the skimmer. The arm is vented (see cut sheets) to allow the orifice size to control the flow rate. The exception is the 6” skimmer uses a 6” Sch 40 PVC due to difficulty sourcing 5” PVC pipe. Many generic sketches or details of skimmers appear to use a barrel the same size as the inlet, but these do not accurately show features of our skimmers. Please refer to the cut sheets on this web site.
No, not appreciably. When the barrel or “arm” is flat or has just a slight slope the flow rate will be just slightly constricted. Once the slope increases, say 6” to 12”, the smaller pipe will carry the flow coming through the inlet/orifice. This has been confirmed through testing.
That depends on where the sediment basin is located. In North Carolina it is 1 to 3 days. In Pennsylvania it is 4 to 7 days. Where there are no specifications 3 days is generally recommended.
Keep in mind that the faster the basin is to be drained, the larger (and more expensive!) the skimmer required to do it.
Just one! This allows the skimmer to be pulled to the side of the basin for inspection or maintenance. Using a post on both sides of the pipe prevents pulling it over.
The color gives the size of the skimmer. Refer to the color chart for reference. These colors have only been in use since Spring 2007.
Yes. As long as care is taken to disconnect the outlet end of the hose so it can be reused and the skimmer has not been damaged through use or removal. The skimmer is made so the barrel or “arm” can be disconnected from the inlet extension for moving and storage. It will probably be necessary to calculate and use a different size orifice when the skimmer is reused in a different basin.
Realistically, often no one is willing to get muddy disconnecting the hose, so a backhoe is used to grab the inlet to pull it loose, which breaks the skimmer.
Yes, AS LONG AS the orifice is sized using the flow rate FOR THE LARGER SIZE, not the smaller size or the size specified.
For example; say the erosion control plan specifies using a 3” Faircloth Skimmer with a 2.5” diameter orifice but the contractor has a 4” on hand. The 4” could be used AS LONG AS the flow rate through the 4” was adjusted by sizing an orifice based on the volume of the basin, the number of days to drain the basin, and the specifications for the 4”.
Using the 4” with a 2.5” orifice would not work because it would drain the basin faster because the head on the 4” inlet is greater than the head on the 3”.
The skimmer includes the float, the inlet, rope, the flexible hose, the orifice plug and adjustable cutter, and instructions. It does not include the barrel or “arm” because it is too long to ship by UPS. The Sch 40 PVC pipe for the barrel is readily available at local suppliers.
The skimmer comes assembled except for a couple of pieces that must be glued on.
If there is a straight pipe through the dam, usually on small ponds or traps without riser structures, the skimmer comes with couplings to attach the flexible hose to the pipe. Couplings and adaptors may be required if the pipe is larger than the coupling on the hose.
Where the basin has a metal outlet structure, the connection can be made to a pipe stubout on the riser. On a concrete riser, a steel plate with an appropriate size female coupling welded on it can be bolted and sealed over a hole through the side. Instructions for fabrication of an adapter for a concrete structure are available here.
Refer to the skimmer cut sheets and instructions for details.
Ideally, when the outlet structure is fabricated a stubout will be welded to the side of the vertical structure at the appropriate location for the particular pond. The size of the stubout should be at least the diameter of the hose to be attached. The stubout can be corrugated with a flange or other type of attaching point on the connecting end for the skimmer hose. If the stubout is smooth steel the end should be threaded so a female coupling can be attached. The male nipple on the outlet end of the hose would be screwed into the female coupling to connect the skimmer.
If a stubout is not already on the corrugated riser, there are at least two ways to attach the skimmer hose. First, have a hole cut in the riser and weld the necessary stubout in the hole, making sure it is secure and watertight. The second method, is to use a device called an Inserta Tee, available from Inserta Tee, that can be installed to create a connection point. Installation requires using the appropriate size hole saw to cut a hole in the corrugated rise. The Inserta Tee fits in the hole and is compressed against the inside and outside of the pipe to create a watertight connection.
It has never been tested for this use. There is concern that the inlet does not sit deep enough under the water to prevent pulling air into the inlet that would break the prime.