Floc Mat

What is a Floc Mat®?

A Floc Mat is a geotextile-based treatment system that uses embedded flocculant to remove suspended solids from surface water runoff. It passively treats that water that flows across or through the mat, promoting particle settlement and reducing turbidity.
How does the Floc Mat® work?

As water flows over the mat, it comes into contact with slow-release Gel Flocculant that binds fine sediment particles together into larger clumps. These heavier particles then settle out, helping to keep downstream water clear and compliant with discharge limits.
When should I use a Floc Mat?

Use Floc Mats whenever activities (construction or otherwise) may generate fine sediments. These activities typically include earthworks, stockpile management, dewatering, or haul road runoff but can extend to conservation, habitat creation or restoration projects. A Floc Mat is particularly valuable where traditional silt control methods alone aren’t enough and treatment is needed to meet discharge quality standards.
Are Floc Mats safe for the environment?

Yes, our Floc Mats are designed to be environmentally responsible. They are 100% biodegradable. The flocculant is securely embedded in the mat and released in low doses, minimising risk. The materials used are non-toxic, and the mats can be safely removed and disposed of at the end of the project – or left in-situ to create a natural habitat.
Do I need a permit to use a Floc Mat?

If you are discharging treated water to a surface watercourse or drainage system, you may need a discharge permit or consent from your local environmental regulator. We recommend checking with your regulator before installation but will talk you through the process when you make an enquiry.
Can I install Floc Mats myself?

Yes, Floc Mats are simple to install and come with clear guidance. They are designed for quick deployment by site staff and can be anchored with sandbags or stakes. Visit our installation section for more detailed information or contact us for support. We can also supply you with a list of approved installers.
How long do Floc Mats® last?

A Floc Mat will generally remain effective for three months but increases in sediment loading will shorten this period. Conversely, if there is little sediment in the water to be treated this can lead to a longer life span.
Can Floc Mats be used with other water treatment measures?

Absolutely. Floc Mats are most effective when used in conjunction with other site-specific measures, in fact our Silt Capture Channel is formed using a combination of our products including these mats. Our team can recommend the best combination for your project.
Do you offer technical support or site visits?

Yes. We regularly support clients with on-site assessments, installation advice, pollution prevention training and compliance planning. Contact us to arrange a visit or speak to one of our technical specialists. We happily provide practical advice and support to ensure the right product is used effectively.
What is the difference between our In-ditch Polishing Point and In-ditch Treatment Point techniques?
- In-ditch Polishing Point: consists of just Floc Mats, Silt Mats and Silt Wattles for a capturing and separating silt from flowing water. It is designed to ‘polish’ the water rather than our other treatment alternatives better designed for bulk drop out.
- In-ditch Treatment Point: includes the use of Gel Flocculant to bind fine silt particles to treat the water, as well as our mats which capture the suspended material while the surface water flows over them.
What kind of maintenance is required?

Maintenance is minimal but important. Inspect mats weekly or after heavy rainfall to ensure they are correctly positioned and not clogged. Replace if water clarity starts to decline.
How can I order or get more information?

You can contact us directly for quotes or tailored site support, visit our product’s technical section for downloadable brochures, installation guides and videos. We’re always happy to help.

Gel Flocculant

How is Gel Flocculant deployed on site?

Blocks can be placed directly in flowing ditches or drains, or inserted into a Pipe Reactor or Clearflow GF Reactor for pumped applications. All deployments are supported by our specialist technical team using site specific calculations and Settlement Tests to ensure correct dosage, installation and maintenance.
What stage of a project can Gel Flocculant be used?

Gel Flocculant can be used at any stage of project, however it is most effective when we are involved early on. Early engagement allows our technical team to plan correctly and take a process driven approach to specification; saving money, time, reducing carbon and protecting the environment. Reactive use is also possible, but always follows a structured process to ensure correct usage and efficacy.
How quickly does sediment settle using Gel Flocculant?

Most silt settles within seconds, as the flocculation process dramatically accelerates particulate settling and enables clean discharge in line with regulatory requirements. Watch our video showing one of our settlement tests in action.
Is it safe to use near aquatic habitats?

Yes. Gel Flocculant is a non toxic, regulator approved technology that has been independently validated as safe for aquatic environments. Correct specification through a Settlement Test ensures effective treatment without risk of overdosing.
Do you offer technical support or site visits?

Yes. We regularly support clients with on-site assessments, installation advice, pollution prevention training and compliance planning. Contact us to arrange a visit or speak to one of our technical specialists. We happily provide practical advice and support to ensure the right product is used effectively.
What is the difference between our In-ditch Polishing Point and In-ditch Treatment Point techniques?
- In-ditch Polishing Point: consists of just Floc Mats, Silt Mats and Silt Wattles for a capturing and separating silt from flowing water. It is designed to ‘polish’ the water rather than our other treatment alternatives better designed for bulk drop out.
- In-ditch Treatment Point: includes the use of Gel Flocculant to bind fine silt particles to treat the water, as well as our mats which capture the suspended material while the surface water flows over them.
How can I order or get more information?

You can contact us directly for quotes or tailored site support, visit our product’s technical section for downloadable brochures, installation guides and videos. We’re always happy to help.

In-ditch Polishing Point

What is an In-ditch Polishing Point?

We’ve designed a passive treatment point combining Floc Mat®, Silt Wattle and Silt Mat™ to capture fine silts in drainage channels. The specific layout and product combination is a result of years of refinement of working with the construction industry to control silt pollution on site.
Does an In-ditch Polishing Point need power or pumps to work?

No. This system works passively with flowing water, reducing carbon footprint and maintenance costs.
Where can it be used?

Our In-ditch Polishing Points can be created in ditches, swales, culverts or any location where silty water collects or flows. This technique has been designed to make the most of existing topography and other infrastructure readily available on site.
How is it secured?

The mats can be fixed with metal stakes (soft beds) or sandbags (hard beds). Watch our installation video or download our CAD drawings for further advice.
What site conditions should be considered?

Our In-Ditch Polishing Point should be installed in shallow, slow flowing channels with gentle gradients (up to 3 degrees) where water depth typically does not exceed 300 mm. For slopes greater than 3 degrees, use check dams to slow water.

The system is designed so that Floc Mats® are the first point of contact, treating fine suspended sediment as runoff enters. Flow is then slowed further by Silt Wattles, allowing the Silt Mats™ to capture and retain the treated sediment. We recommend to line or seed the ditch to prevent scour.
What is the difference between our In-ditch Polishing Point and In-ditch Treatment Point techniques?
- In-ditch Polishing Point: consists of just Floc Mats, Silt Mats and Silt Wattles for a capturing and separating silt from flowing water. It is designed to ‘polish’ the water rather than our other treatment alternatives better designed for bulk drop out.
- In-ditch Treatment Point: includes the use of Gel Flocculant to bind fine silt particles to treat the water, as well as our mats which capture the suspended material while the surface water flows over them.

Pipe Reactor

What is a Pipe Reactor?

A Pipe Reactor is the mixing device for pumped water treatment systems. It houses replaceable Gel Flocculant blocks which are used to separate heavy and fine silt particles from surface water before it runs off the site. Without intervention, surface water run off from construction sites often cause silt pollution events in local rivers and other watercourses.
How much water does a Pipe Reactor treat?

The Pipe Reactor treats up to 1,800 litres of silty water per minute, providing an affordable and practical water treatment solution for construction sites.
Must I always use a pumped system for treating water?

No, we offer passive water treatment solutions like our In-ditch Polishing Point design as well as pumped ones, such as our Pipe Reactor or GFR units. Our technical team will be delighted to help you work out the best solution for your site. We offer a no-obligatory 30 minute meeting to talk over your site.
Do I need a Pipe Reactor when using Gel Flocculant?

If a site is pumping water then a Pipe Reactor is often linked up to the pump to help with consistent dosing of Gel Flocculant to treat silty surface water. In some scenarios, sites can use Gel Flocculant without a Pipe Reactor, this is what we call a passive treatment system. Our technical team can help guide you through the best solution for your site.
Should the Pipe Reactor be used in conjunction with our other silt control solutions?

Yes, in most cases. When water is pumped through a Pipe Reactor it is best paired with our engineered Silt Capture Channels, made up of biodegradable Silt Mats™, Floc Mats® and Silt Wattles. These capture separated sediment at the outlet. In some scenarios, such as simple dewatering, this additional step may not be required.

The Pipe Reactor can also be used to recirculate attenuation or settlement ponds, providing batch treatment of water prior to controlled discharge.
What happens to the silt and other contaminants once it has been separated from the water?

A Pipe Reactor binds fine particles so they can be removed from the water. To stop silt from resuspending, it must be captured and retained. We recommend using Silt Capture Channels or specially designed mats, depending on site conditions. Our full range of silt control products and expert support ensures effective, site-specific water treatment; our technical team can help you work out your requirements to suit you site needs and budget.
Do you offer technical support or site visits?

Yes. We regularly support clients with on-site assessments, installation advice, pollution prevention training and compliance planning. Contact us to arrange a visit or speak to one of our technical specialists. We happily provide practical advice and support to ensure the right product is used effectively.
How can I order or get more information?

You can contact us directly for quotes or tailored site support, visit our product’s technical section for downloadable brochures, installation guides and videos. We’re always happy to help.

Settlement Tests

What is a Settlement Test?

A Settlement Test is a laboratory test carried out by Frog Environmental to determine the natural settlement rate of suspended solids and assess water clarity outcomes. Results inform silt control measures and can include validation of Gel Flocculant where requested.
Why is settlement testing important on a construction site?

Settlement Tests are recommended at both pre-construction phase to help plan ahead and budget for silt pollution risks, and during construction to monitor changes to dynamic sites and address changes needed to existing water treatment systems. We recommend this test is carried out on all sites.
How are the results used?

Our Settlement Test report provides practical recommendations for silt control design and, if applicable, flocculant selection. We offer a video or phone consultation as part of the service to discuss the results and appropriate treatment measures.
What should I send?

Either a 2 litre water sample, a 500 g subsoil sample with 2 litres of local freshwater for mixing, or a 2 litre composite sample of silty water. Please label all items clearly to help us identify your samples. Contact us first so we can get you booked in with our laboratory team.
Can I use tap water?

No. Use fresh rainwater or local surface water to reflect site conditions. Avoid stagnant water.
How soon after taking the sample should Frog Environmental receive them?

Samples should arrive with us within 72 hours of the sampling. Please inform your Frog contact when samples are dispatched so we can book them into our laboratory’s workflow on arrival.
How should I package and address samples?

Place labelled samples in a strong box or bag, enclose our Chain of Custody sample detail form, and attach our address form to the outside.

Notifying your contact at Frog ahead of sending as it helps ensure samples are expected and booked into our laboratory.

Silt Control

What happens to the silt and other contaminants once it has been separated from the water?

A Pipe Reactor binds fine particles so they can be removed from the water. To stop silt from resuspending, it must be captured and retained. We recommend using Silt Capture Channels or specially designed mats, depending on site conditions. Our full range of silt control products and expert support ensures effective, site-specific water treatment; our technical team can help you work out your requirements to suit you site needs and budget.
What is a Settlement Test?

A Settlement Test is a laboratory test carried out by Frog Environmental to determine the natural settlement rate of suspended solids and assess water clarity outcomes. Results inform silt control measures and can include validation of Gel Flocculant where requested.
Why is settlement testing important on a construction site?

Settlement Tests are recommended at both pre-construction phase to help plan ahead and budget for silt pollution risks, and during construction to monitor changes to dynamic sites and address changes needed to existing water treatment systems. We recommend this test is carried out on all sites.
Do you offer technical support or site visits?

Yes. We regularly support clients with on-site assessments, installation advice, pollution prevention training and compliance planning. Contact us to arrange a visit or speak to one of our technical specialists. We happily provide practical advice and support to ensure the right product is used effectively.
How can I order or get more information?

You can contact us directly for quotes or tailored site support, visit our product’s technical section for downloadable brochures, installation guides and videos. We’re always happy to help.

Silt Control Response Kit

What’s the difference between our standard and treated kits?
- The standard kit uses physical attenuation and filtration (Silt Mats™ and Silt Wattles) to clean silty water. It can be used on land or in water depending on the project.
- The treated kit adds Floc Mats® containing Gel Flocculant particles to target fine clays. This kit can be used in-ditch or across dispersion fields and requires regulator approval for using a flocculant. Floc Mats must not be used directly in a natural watercourse as it contains flocculant.
How do I select the right kit for my site?

We work with you to set the correct specification and layout based on flows, gradients and discharge requirements. Our Settlement Testing service underpins dosing choices where treatment options such as Gel Flocculant is proposed.
Does the kit include pegs/fittings?

No, fittings/pegs are not included. Materials may need to be weighted down on site or pegged in place, depending on flow rates.
Are the materials reusable or biodegradable?

Silt Control Response Kit’s components are biodegradable and suited to temporary works for reuse/disposal protocols. See Silt Mat™/Floc Mat® product guidance and videos.

Silt Fence

What is a Silt Fence and what does it do?

Made from woven geotextile fabric, a Silt Fence is a temporary barrier which intercepts overland sheet-flow runoff, slowing it down to allow coarse silt to settle out from the water.
Why are silt fences used on construction sites?

They help prevent silt pollution from disturbed soils, protecting nearby drains, ditches, and watercourses. They also serve as temporary site boundaries and control erosion from stockpiles or site slopes.
In which situations are silt fences most effective?

They are best used for construction sites when intercepting sheet flow on low to moderate gradient sites (not for concentrated flow) and to demarcate limits of disturbance, such as sensitive areas near wetlands or buffer zones.
What are its limitations?

Silt Fences can clog quickly, and provide poor performance against fine sediments or during heavy flows. We are specialists in silt control and water quality and can offer advice and our own alternative products designed for superior performance where silt fences may fail.
Where should silt fences not be used?

Avoid installing them across watercourses, channels, or areas with concentrated flow. There are better solutions we can help you with for these scenarios to manage silty water on construction sites.
Do you offer technical support or site visits?

Yes. We regularly support clients with on-site assessments, installation advice, pollution prevention training and compliance planning. Contact us to arrange a visit or speak to one of our technical specialists. We happily provide practical advice and support to ensure the right product is used effectively.

Silt Mats

What is a Silt Mat™ and how does it work?

Silt Mats™ are biodegradable geotextile products designed to capture sediment and silt carried by surface water runoff. They help prevent pollution by filtering out fine particles before they enter drains, watercourses, or the wider environment.
When should I use a Silt Mat™ on a construction site?

Silt Mats are ideal for use during groundworks, excavation, stockpiling, or any activity that disturbs soil and risks waterborne sediment runoff. They’re especially useful near site perimeters, drainage outfalls, or temporary haul roads.
Can I use Silt Mats in conjunction with other water treatment systems?

Yes – in fact, we often recommend using Silt Mats as part of a layered approach alongside our product range for enhanced performance. Contact us to discuss site specific solutions with our Technical Team.
How long do Silt Mats™ last?

Silt Mats typically last between two and six months in active use, depending on exposure, water flow, and sediment load. They will biodegrade over time, but we recommend regular checks and replacement if signs of clogging or wear appear.
How do I install a Silt Mat?

Installation is straightforward. Lay the mat flat on the surface or within the ditch, anchoring it with sandbags, or stakes to keep it in place. Watch our installation video or download our CAD instructions for full guidance.
Can Silt Mats handle heavy rainfall?

Our Silt Mats are engineered to cope with varying weather conditions, including heavy rainfall. Performance depends on correct installation and site conditions. In high-flow areas, combining mats with additional control measures may be necessary. Silt Mat must be properly weighted to withstand high flow conditions.
Are Silt Mats biodegradable and environmentally friendly?

Yes, our mats are fully biodegradable and made from natural fibres. And are delivered nationally using a carbon neutral delivery service.
Do you offer technical support or site visits?

Yes. We regularly support clients with on-site assessments, installation advice, pollution prevention training and compliance planning. Contact us to arrange a visit or speak to one of our technical specialists. We happily provide practical advice and support to ensure the right product is used effectively.
What is the difference between our In-ditch Polishing Point and In-ditch Treatment Point techniques?
- In-ditch Polishing Point: consists of just Floc Mats, Silt Mats and Silt Wattles for a capturing and separating silt from flowing water. It is designed to ‘polish’ the water rather than our other treatment alternatives better designed for bulk drop out.
- In-ditch Treatment Point: includes the use of Gel Flocculant to bind fine silt particles to treat the water, as well as our mats which capture the suspended material while the surface water flows over them.
What kind of maintenance is required?

Maintenance is minimal but important. Inspect mats weekly or after heavy rainfall to ensure they are correctly positioned and not clogged. Replace if water clarity starts to decline.
How can I order or get more information?

You can contact us directly for quotes or tailored site support, visit our product’s technical section for downloadable brochures, installation guides and videos. We’re always happy to help.

Silt Net

What is Silt Net?

Silt Net is a 100% biodegradable rolled coir product designed to improve water treatment performance and provide erosion control. It is supplied untreated or pre-treated with Gel Flocculant™ for binding fine clay and silt particles.
How does Silt Net work in lagoons and ponds?

In settlement lagoons and treatment ponds, Silt Net is suspended as a curtain across the water. This breaks up laminar flow, increases flow pathways and retention time, and enhances settlement of suspended solids.
How is Silt Net used in ditches?

In ditches, Silt Net is rolled out along the base and staked in place. This slows water movement, captures sediment, and helps reduce erosion.
What are the treated and untreated options?

The untreated version slows flows and traps suspended solids. The treated version is pre-impregnated with Clearflow Gel Flocculant™, which binds fine particles and polishes the water.
How long does Silt Net last?

Silt Net provides structural performance for over five years before naturally breaking down, leaving no synthetic residue.
Can Silt Net be retrofitted into existing ponds and lagoons?

Yes. Supplied in rolls, Silt Net can be deployed into existing lagoons and ponds without major infrastructure changes.
What happens once Silt Net breaks down?

As a fully biodegradable product, it leaves no plastic waste. Depending on site conditions, it can be safely discarded or seeded to create habitat.
When should I choose Silt Net over other solutions?

It is most effective when suspended in lagoons to extend flow paths, or rolled in ditches to reduce erosion. Our technical team can help identify the right solution for your site.
Do you offer technical support or site visits?

Yes. We regularly support clients with on-site assessments, installation advice, pollution prevention training and compliance planning. Contact us to arrange a visit or speak to one of our technical specialists. We happily provide practical advice and support to ensure the right product is used effectively.
How can I order or get more information?

You can contact us directly for quotes or tailored site support, visit our product’s technical section for downloadable brochures, installation guides and videos. We’re always happy to help.

Silt Wattle

What are Silt Wattles?

Silt Wattles are used to control silt-laden runoff, trap sediment, and slow water flow on construction sites, preventing pollution and erosion.

They are a circular shaped silt management and soil stabilisation product available in different thicknesses and lengths, filled with durable woodchip fibre encased in a durable mesh netting.
How do they work?

Silt Wattles act as temporary check dams or barriers that intercept surface water, slowing it down so that sediment can settle out of suspension. They help prevent silt from reaching drains, watercourses, or sensitive areas.

Silt Wattles have multi-purpose functionality; they can be used on land or in water to prevent silt pollution.
Where should I install Silt Wattles on site?

We provide self installation guidance on different configuration options depending on the construction site, but generally Silt Wattles are placed at the base of slopes, around stockpiles, along site perimeters, near watercourses, along river banks or in rivers during works. They are also effective across temporary channels or along haul roads to slow runoff and reduce silt movement.
Do Silt Wattles require anchoring?

Installation is key for optimal performance. Silt Wattles often need to be staked securely or weighted with sandbags to prevent water from flowing underneath or dislodging them during heavy rainfall. See our Silt Wattle installation guidance for support.
How long do Silt Wattles last?

On average, they provide effective performance for over 12 months, depending on site conditions. While the woodchip filter is biodegradable, it will take time for them to degrade.
Are Silt Wattles suitable for steep slopes or high flow areas?

They can be used on moderate slopes and in low-to medium-flow areas. For steeper gradients or high-volume flows, additional measures such as erosion control mats or flocculant products may be required for optimal performance.
What maintenance is needed?

Inspect them regularly, especially after heavy rain. Remove built-up sediment, check for undercutting, and reposition or replace the Silt Wattles if they become damaged or ineffective.
Can Silt Wattles be used with other water management products?

Yes, they work well as part of a broader surface water and sediment control strategy. Combine with our Silt Mats™, Floc Mats®, or other settlement systems for enhanced protection.
Do you offer site-specific advice for placement of Silt Wattles?

We do. We offer a free 30 minute phone or online consultation with our technical team to discuss your project. Our team regularly visit construction sites and river restoration projects across the UK to provide tailored advice and support. Get in touch if you’d like help assessing your site and selecting the right combination of silt control products.
How do I order Silt Wattles?

You can contact us for availability, pricing, and delivery options. We’re happy to help you choose the right quantity and setup for your project.
What is the difference between our In-ditch Polishing Point and In-ditch Treatment Point techniques?
- In-ditch Polishing Point: consists of just Floc Mats, Silt Mats and Silt Wattles for a capturing and separating silt from flowing water. It is designed to ‘polish’ the water rather than our other treatment alternatives better designed for bulk drop out.
- In-ditch Treatment Point: includes the use of Gel Flocculant to bind fine silt particles to treat the water, as well as our mats which capture the suspended material while the surface water flows over them.

Training

Water Treatment

Do you offer technical support or site visits?

Yes. We regularly support clients with on-site assessments, installation advice, pollution prevention training and compliance planning. Contact us to arrange a visit or speak to one of our technical specialists. We happily provide practical advice and support to ensure the right product is used effectively.
How can I order or get more information?

You can contact us directly for quotes or tailored site support, visit our product’s technical section for downloadable brochures, installation guides and videos. We’re always happy to help.

Working in Water

Do you offer technical support or site visits?

Yes. We regularly support clients with on-site assessments, installation advice, pollution prevention training and compliance planning. Contact us to arrange a visit or speak to one of our technical specialists. We happily provide practical advice and support to ensure the right product is used effectively.
How can I order or get more information?

You can contact us directly for quotes or tailored site support, visit our product’s technical section for downloadable brochures, installation guides and videos. We’re always happy to help.

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