Marlee Float FAQs

A skimmer, also called a surface drain, is an erosion control device used in sediment basins to increase sediment trapping efficiency.  When muddy water enters the basin, the sediment begins to settle to the bottom.  When looking at the water column, the cleaner water is towards the surface.  Skimmers are designed to release the water from near the surface first and to do so slowly, allowing time for the sediment to settle to the bottom of the pond.

This depends on state or local requirements.  Generally states require that the skimmer be sized to drain the basin volume over a specified time frame.  For example, South Carolina requires that the sediment basin be drained from near the surface and over a time period of 2-5 days, with 3 days being preferred.  A simplified method is to determine the volume of the basin to be drained and then using the average flow rate for each skimmer determine which one(s) meet the required drawdown time range.   If a conservative approach is used then this is a generally accepted method for selecting skimmers.

Although skimmers are often referred to as “constant-flow” devices, testing has shown the flow rates actually vary by basin depth.  Because the flow rates do vary, a more accurate way to incorporate the device into the design is by inputting the actual discharge rate at given elevations into stormwater modeling software.  We provide flow rate data based upon our third party test results for use by engineers when a more precise design is preferred or required.

We have also developed an easy to use design tool for use by engineers that takes into account the actual flow rates of the Marlee Float, as well as basin size and depth. Those tools can be found here »

This is a very common question and the answer is YES! The device has been thoroughly tested and as long as it is installed properly will perform well.

Our new coupling is a custom bellows style coupling that provides more than 90 degrees of flexibility while helping to maintain the skimmer in the proper position in the pond. It connects to standard IPS dimensions. A PVC or HDPE stubout from the riser is preferred.

If you have a need for a custom solution, it can be provided. Please contact us and we will be glad to assist you

Because this skimmer is made of UV-resistant materials and has a long life, it is a cost-effective tool for use as a part of the outlet system in permanent basins, both wet and dry. The unique design allows for very low flows while minimizing clogging, making it an excellent alternative to small orifices often needed to meet permanent water quality requirements. Engineers have informed us that use of the Marlee Float in place of a low flow orifice has also saved up to 20% on required pond volumes.

In addition, we are currently testing a water quality skirt that will allow the use of our skimmer to meet stringent water quality requirements for TSS, hydrocarbon and other pollutant removal. This will be available later this summer.

Using the comparison chart, you can compare the flow rates of the Marlee Float to other brands.  Many plans will specify a basin volume and range for draw down time, which allows for easy confirmation of suitable equivalents using the comparison chart or design tool (coming soon).  Ultimately it is up to the Engineer of Record to allow a brand substitution if not specifically allowed on the plans or if questions arise.

If there are any questions about how the Marlee Float compares to other leading skimmers on the market we will be glad to assist in verification and coordination with the Engineer of Record and/or local regulatory agency as needed.  Contact us and one of our specialists will be happy to assist.

The device meets all EPA requirements for skimmers/surface drains, as well as requirements for use in most states.

We have taken an additional step to have the Marlee Float third party tested and the flow rates verified by a Professional Engineer, so design professionals have assurance that our product functions as published. We also have written approvals from many areas, with more pending. Our current approvals can be found here.

In 2013, South Carolina revised its CGP to include requirements for surface withdrawal from sediment basins. In the Fall of 2012, the state notified engineers of this coming requirement, as well as other changes to the CGP. In December 2012 our daughter had a bad night and wanted to sleep with us, which was very unusual. She is a “rooter” and I had knees and elbows in my back all night. During this restless time, I had an idea for a skimmer. I thought about it for several hours and even got up and made a sketch of it. We ended up building it and eventually began to sell it. We thought it was only right to name it after our daughter Marlee that inspired the idea.

We have compiled a detailed comparison chart. The flow rates for the Marlee Float skimmers are similar to the Faircloth skimmer and others, however, there are variations. It is important to compare flow rates, not necessarily size of skimmer or orifice, when comparing brands or looking for an “equal”.  Because most sediment basins are allowed to drain over a range of time, it is not usually necessary to match flow rates exactly.   The Engineer of Record should approve a change from one skimmer brand to another if there are any questions.  Our design tool can aid in confirming the appropriate skimmer size can be found here.

The primary differences between the Marlee Float and most other skimmers are:

• It is made of HDPE, stainless steel parts and custom molded polyethylene rings, so it is much more UV resistant than PVC models and, therefore, reusable on multiple sites;
• The product design, characteristics and lifespan allow it to be used as part of the permanent outlet system of basins;
• Its unique vortex design prevents clogging, traps floatables in the basin and increases trapping efficiency;
• It has no moving parts and is simple to install;
• It doesn’t get stuck in the mud in the pond.

The simple installation can be completed by one person in approximately 5 minutes and is accomplished by installing a rigid pipe into the supplied coupling at the skimmer and then gluing or screwing it together and installing our custom flexible rubber coupling at the riser and gluing or screwing it together, in addition to the provided pipe clamps Detailed cut sheets and installation instructions can be found here.

We suggest the use of a cordless drill to aid in tightening the clamps on the flexible coupling and installing screws through the couplings into the pipe. For the Model 3 the weight is removable for easier handling by unscrewing four wing nuts.

The only part not included is the barrel connecting the skimmer to the outlet structure. The barrel can be PVC for temporary sediment basins, but should be UV Resistant for permanent applications. The barrel length should be 1.4 times the height of the riser structure.

HDPE is highly UV resistant.  Although no specific life span is specified for HDPE, we would expect the device to last for a minimum of 20 years and likely much longer.  It comes with a one-year warranty.

Because of the long life span, the skimmer can be reused on future projects and because each model of the Marlee Float has a range of flow rates it is adaptable for different size basins.