Floating Cover FAQ

AWTT stands for Advanced Water Treatment Technologies Inc., an American manufacturer founded in 2004, currently headquartered in Harlingen, Texas. AWTT designs and produces modular floating cover systems for liquid storage applications. The bulk of production is in North America (Tijuana, MX and Trenton, SC), with additional Hexprotect AQUA production in Budapest, Hungary and Jebel Ali, UAE to serve EMEA and Middle East markets with shorter lead times. The company maintains 700+ installations across 25 countries on five continents, with over 20 million square feet of cover deployed globally, serving 320+ customers.

Floating covers are individual modular elements (balls or hexagonal tiles) that are placed on the surface of a liquid. They self-arrange into a uniform cover that floats up and down with liquid level changes. Unlike traditional membrane covers, they are modular, maintenance-free, and do not require any structural support.

• Heat loss reduction (up to 60-90% heating cost savings)
• Evaporation reduction (up to 90-98%)
• Odor & VOC control and emission reduction (H2S, NH3, mercaptans, VOCs - up to 96%)
• Algae prevention by blocking UV light (cyanobacteria, harmful algal blooms)
• Wildlife deterrence (birds, waterfowl, deer - MBTA compliance)
• Ammonia volatilization control (up to 90% reduction)
• Chemical consumption reduction
• Ice/snow/rain protection (frost resistant to -70F / -57C)
• Source water protection (pathogen exclusion, debris blocking)

Municipal utilities, industrial plants, water treatment facilities, wastewater treatment plants, airports, military installations, theme parks, mining operations, petrochemical plants, dairies, fish farms, nurseries, paper mills, and more.

Hexprotect is a patented, self-ballasting hexagonal tile floating cover. When placed on a liquid surface, the tiles automatically fill with water, increasing their weight by more than 260%. This self-ballasting makes the cover wind resistant up to 75 MPH without requiring any external anchoring.

The Hexprotect tile is designed so that when it is placed on water, it automatically takes in water through its proprietary design, increasing its weight from 172g (dry) to approximately 455g (installed). The cover floats with slightly more than 50% of its shell above water.

Hexprotect AQUA is AWTT's flagship ballasted hexagonal tile, designed for extreme wind conditions. The tiles are ballasted (pre-filled with water ballast), not self-ballasting -- only the regular Hexprotect tile (not sold) is self-ballasting. It achieves 99% surface coverage with a wind resistance rating of 130+ MPH (209+ km/h). The internal water ballast anchors the cover against wind uplift without requiring any external fasteners, cables, or pond modifications.

Hexprotect AQUA Specifications:

Hexprotect AQUA is the only AWTT product offered in NSF/ANSI 61 certified, FDA-compliant HDPE resin for potable water applications. The certification is held by the resin; the finished cover assembly is not itself NSF-certified.

The Hexprotect Max R is an insulated version of the hexagonal tile cover featuring 2.5-3 inches of factory-bonded closed-cell polyurethane foam that provides an insulation value of R-17+ (up to R-21), equivalent to a well-insulated building wall. The foam provides approximately R-6 to R-7 per inch. This makes it ideal for applications where heat retention is critical, such as anaerobic digesters and heated process ponds. Heating costs can be reduced by up to 90%. Expected life time is 25 years.

Hexprotect Max R Specifications:

ROI for Hexprotect Max R:

• A single-acre open digestion lagoon can require $80,000-$250,000+/year in heating
• Post-installation savings: $60,000-$200,000+/year per acre
• Typical payback period: 12-36 months
• Lifetime ROI: 10-20x initial investment over 25-year lifespan

The Rhombo (also called Hexa Armor or Hexoshield) is a patented, multi-faceted ball designed for maximum coverage and stability. Unlike traditional round balls, the Rhombo has flat faces that interlock with adjacent elements, providing up to 99.99% coverage with no stacking or overlapping.

• Rhombo Hexoshield 66 (114 mm outer / 100 mm inscribed): Patented hybrid rhombus-hexagonal geometry, 99% coverage, 130 MPH wind resistance (water-ballasted), R-4 insulation, buoyancy 25 lb/ft² (122 kg/m²), evaporation reduction up to 98%
• Rhombo Hexoshield 189 (189mm): 7.5 inches diameter, 210g weight, 2.61/sq.ft, 28/sq.m, 90+ MPH wind resistance, R-8 insulation, buoyancy 50 lb/ft² (244 kg/m²), evaporation reduction up to 98%, heating cost reduction up to 80%

Yes. The Rhombo Hexoshield 66 has a load-bearing capacity of 25 lb/ft², and the Rhombo Hexoshield 189 supports 50 lb/ft² - enabling direct personnel access, equipment deployment, and heavy snow accumulation directly on the cover surface.

• Symmetrical on all sides for best coverage
• Large flat faces for optimum wind resistance (NO stacking / NO overlapping)
• Proprietary patented faceted shape for optimized coverage
• Up to 99.99% coverage
• Evaporation reduction up to 98%
• Emission reduction up to 96%
• Life expectancy 25+ years

Installation is extremely simple and generally consists of unloading the product directly onto the liquid surface. No structural support, anchoring, or specialized equipment is required.

For Hexprotect / Hexoshield tiles:

1. Tiles come in mesh/net bags (max 30-40 lbs per bag), easily lifted by 1-2 persons
2. Lift the bag over the basin or at the edge, with the opening facing downward
3. Loosen the string or cut the bag open; tiles fall onto the liquid surface
4. Tiles self-arrange into a uniform interlocking pattern

For Armor Balls:

1. Balls come in plastic net bags (max 200 balls per bag)
2. Simply dump the balls into the basin
3. Balls self-arrange to provide minimum 91% coverage

AWTT recommends at least 2 persons for safety reasons.

No. AWTT supplies product only and does not sell installation services. There is no installation line item in an AWTT quote and no installation contract to negotiate. The modules are set at the water's edge and poured straight in; the only person who needs to be qualified is the forklift operator. For elevated tanks, a boom-style forklift is used to reach over the wall.

This is why total project cost for a modular cover equals the cover plus freight and nothing else.

1. Check the delivered quantity against the BOL (Bill of Lading)
2. Verify basin openings: Intake and outlet openings must be smaller than the diameter of the cover elements to prevent blocking
3. Clear surface debris: Remove any floating debris or viscous layers to help the cover distribute evenly

No. AWTT recommends deploying only 90% of the covers initially. Wait a couple of days for the elements to form a uniform pattern, then add the remaining 10% as needed. It is much easier to add more than to remove excess.

Yes. AWTT floating covers fit all shapes and geometries - round, rectangular, irregular, or any other configuration. The individual elements conform to any shape.

AWTT covers are classified as "wind resistant" when coverage is maintained in winds over 70 MPH. Here are the tested results:

No. None of the covers are damaged by wind, no matter how strong. Under extreme conditions (winds over 200 MPH at 35+ degree angles), covers may temporarily stack in spots but automatically reform in seconds once wind subsides.

The water ballast causes the cover elements to float partially submerged (30-50% for Armor Ball AQUA), making them much more resistant to being displaced by wind. The weight of the ballast far exceeds any air pressure buildup. Additionally, the ballasted covers reduce or completely suppress waves, further increasing stability.

No. High winds can actually be beneficial by quickly reshaping and effectively cleaning the covers. They have no long-term negative effects.

This is where the modular design matters most. No floating cover on the market is rated beyond roughly 130 MPH. Above the rating, modules may stack against one side of the pond, then disperse and reform once the wind drops.

The important difference is the failure economics. If individual pieces are ever blown out, they are picked up and put back in at a cost of cents per piece. A solid sheet cover that fails in wind has to be replaced completely. A rating is not a cliff edge for a modular cover in the way it is for a membrane.

Yes. AWTT floating covers block UV light penetration, which is essential for photosynthesis. Without sunlight, algae cannot grow. This is particularly important because:

• Algae increases TSS and CBOD5 in effluent
• Algae deteriorates water taste
• Algae clogs filtration systems
• Algae increases chemical treatment costs

Yes. Aeration can be installed underneath both Armor Ball and Hexprotect systems to ensure aerobic conditions are maintained. The covers do not interfere with aeration.

The covers improve water quality by:

• Preventing algae growth
• Reducing chemical consumption
• Blocking debris and contaminants
• Maintaining water temperature stability
• FDA and NSF approved resins are available for potable water applications

• Drinking water reservoirs (source water protection, algae prevention, NSF/ANSI 61 certified resin option)
• Wastewater treatment plants (lagoons, aeration basins, clarifiers, odor control)
• Biogas & anaerobic digestion (thermal retention, emission control)
• Oil & gas / frac ponds (evaporation control, containment)
• Mining operations (leachate ponds, tailings, heap leach, process water)
• Airports & deicing ponds (bird strike prevention, glycol odor suppression)
• Dairies & agriculture (manure lagoons, ammonia control, irrigation reservoirs)
• Chemical plants (VOC/emission containment)
• Cement plants (process water management)
• Power generation (cooling water, process ponds)
• Industrial water storage (process water, cooling ponds)
• Slurry & tailings ponds (mining, industrial)
• Aquaculture (thermal management for tilapia, catfish, shrimp)
• Theme parks and recreation (e.g., Silverwood Theme Park)
• Military installations (e.g., Joint Base Pearl Harbor-Hickam)
• Nuclear facilities (e.g., Savannah River Site - 2017 DOE Sustainability Award)

Yes. Unlike membrane covers, AWTT floating covers do not obstruct static, moving, or dipping equipment. Elements can be easily pushed aside and the cover automatically reforms as equipment moves or basin configuration changes (e.g., in clarifiers with rotating mechanisms).

Yes. The covers automatically adjust to liquid level changes by rising, lowering, spreading, and restacking as needed. No manual adjustment is required.

Yes. HDPE is resistant to a wide range of chemicals at both ambient (20C/68F) and elevated (60C/140F) temperatures. HDPE is specifically recommended for demineralized water and chromic acid applications.

Resistant (R) at both 20C and 60C:

• Acetic acid, Acetone, Alcohols, Ammonia (aqueous and anhydrous), Ammonium chloride
• Boric acid, Brines, Calcium chloride, Carbonic acid, Caustic soda & potash
• Citric acid, Copper salts, Detergents, Ether, Fatty acids
• Ferric chloride, Formaldehyde (40%), Formic acid, Fruit juices, Glycerine, Glycols
• Hydrochloric acid (all concentrations), Hydrofluoric acid, Hydrogen peroxide (30%)
• Hydrogen sulphide, Hypochlorites, Lactic acid, Mercury, Milk products
• Nickel salts, Nitric acid (<25%), Oils (lubricating, mineral), Phosphoric acid
• Potassium permanganate, Sodium hydroxide, Sulphuric acid (up to 70%), Water, and many more

Limited Resistance (LR) - check specific conditions:

• Chlorine (dry and wet), Methylene chloride, Butyl acetate

Not Recommended (NR):

• Carbon tetrachloride, Chlorobenzene, Chloroform, Cyclohexane, Naptha
• Nitric acid (>50%), Nitrobenzene, Fluorine (dry/wet)

For a complete chemical resistance chart, contact AWTT or refer to the HDPE Chemical Resistance Chart.

• Standard warranty is 10 years (or more, depending on product)
• Wind resistance warranty (Hexoshield): Warranted to handle 50 MPH. Elements that leave the water containment as a result of excessive winds (3+ feet from top of liner) will be refunded after inspection
• Warranty covers defects in materials and workmanship under proper installation and normal use

• FDA: Complies with 21 CFR SS 177.1520, Para. (c) 2.1 and 2 (potable water applications)
• NSF: NSF approved HDPE resins available for special applications
• ARRA: Products comply with the American Recovery & Reinvestment Act (Buy American provisions)
• ISO: Manufacturer is ISO certified

Yes. HDPE is a widely recycled plastic (recycling code #2). At the end of their service life, AWTT covers can be recycled.

Three mechanisms work together:

1. Hexagonal tessellation: Hexagons tile a plane with minimal perimeter-to-area ratio, achieving up to 99% coverage vs. ~9% gaps with circular designs
2. Side-locking tabs: Proprietary edge features prevent tiles from overlapping or climbing under wave motion
3. Factory-sealed water ballast: tiles arrive pre-loaded to 100%–300% of their basic weight, anchoring the cover without any on-site filling, anchoring tiles against wind uplift

Choose modular floating covers when:

• Evaporation control is the primary goal
• Exposed or windy sites (130+ MPH wind resistance)
• In-pond equipment requires unrestricted access
• Limited maintenance budget or no power supply available
• Irregular pond shapes
• Rainwater ingress is acceptable
• Phased or future redeployment is desired

Choose solid geomembrane covers when:

• Gas collection is required (biogas, methane harvesting)
• 100% vapor seal is a regulatory mandate
• Rainwater dilution must be prevented
• Zero-emission containment required

AWTT Armor Balls are engineered with:

• Thicker walls (+10% more than competition on AQUA 275)
• UV resistant HDPE formulation with stabilizers
• Proprietary no-plug/no-seal construction (no leak points)
• Custom water ballast options for wind resistance
• 25+ year life expectancy with warranty (vs. 3-10 years typical for generic shade balls)
• Made in North America with quality assurance
• Chemical resistance rated pH 2-13 for industrial applications
• R-2 insulation value (standard Armor Ball)

Yes. AWTT covers have survived four named hurricanes with zero damage and zero repairs:

• Hurricane Florence (2018, Category 1): 0 repairs
• Hurricane Dorian (2019, Category 1): 0 repairs
• Hurricane Nicole (2022, Category 1): 0 repairs
• Hurricane Helene (2024, Category 4): 0 repairs

All AWTT covers are frost resistant to -70F (-57C). HDPE remains structurally sound at sub-zero temperatures, and polyurethane foam (in MAX R models) maintains R-values in extreme cold. Covers operate successfully in northern Canada, Scandinavia, and other harsh environments.

Yes. Modular covers handle freeze-thaw without damage, unlike geomembrane covers which can be stressed by ice formation. Individual elements can freeze into surface ice and release without structural damage.

Floating covers suppress ammonia volatilization by creating a physical barrier that increases mass transfer resistance, preventing ammonia gas (NH3) from diffusing into the atmosphere. Ammonia remains in the liquid as ammonium (NH4+), retaining its fertilizer value.

• Up to 90% ammonia emission reduction from manure lagoons and slurry tanks
• Cattle slurry: approximately 15% ammonia loss (covered) vs. 100% (uncovered)
• Pig slurry: 5-12% ammonia loss (covered)

At current synthetic nitrogen fertilizer prices ($500-$700/ton), covering a large dairy lagoon can preserve tens of thousands of dollars annually in nitrogen fertilizer value, often justifying installation costs independently.

• Dairy manure lagoons
• Swine waste pits
• Poultry litter impoundments
• Slurry storage tanks
• Chemical and fertilizer plants
• Food processing facilities
• Semiconductor facilities

• Clean Air Act ammonia permit requirements
• Documented passive engineering control for HAP emission reduction
• Reduced EPCRA Tier II reporting thresholds
• Lower site-perimeter air monitoring concentrations

Yes. Individual cover modules interlock or self-align on the water surface, allowing coverage to scale to any reservoir size without structural support, fixed anchoring, or basin modification. Covers self-adjust to water level fluctuations without re-anchoring.

• Uncovered reservoirs in arid regions lose 60-100 inches of water annually to evaporation
• A 50-acre covered reservoir can save 120-200 million gallons annually
• A 100-acre reservoir can conserve over 2 billion gallons yearly (with Hexoshield)
• A 200-acre irrigation reservoir can save approximately 850 million gallons annually

• Raw water costs: $500-$2,000 per acre-foot in arid regions
• 100-acre reservoir annual water savings: $1-4 million
• Installation cost: $50,000-$200,000 for a 100-acre system
• Payback period: 1-5 years
• Operational lifespan: 20+ years of net savings after payback

1. Rhombo Hexoshield - Maximum conservation (98% evaporation reduction)
2. Hexprotect AQUA - Best all-purpose choice (99% coverage, 95% reduction, NSF/ANSI 61 certified resin option)
3. Armor Ball AQUA 275 - High-wind environments (rated 75 MPH)

Decision flowchart (3 questions):

1. Is thermal insulation priority #1? --> Hexprotect MAX R
2. Is wind exposure exceeding 75 MPH? --> Hexprotect AQUA or Rhombo Hexoshield
3. Is budget the primary constraint? --> Armor Ball or Hexprotect SLIM

Yes. Modular tiles allow mixing different products on the same pond to optimize for different areas or requirements.

Yes. AWTT manufactures custom-built floating baffles for industrial lagoons that create optimized flow patterns, increase retention time, and eliminate short-circuiting and dead zones.

• Short-circuiting: Reduces actual hydraulic retention time
• Dead zones: Decreases effective treatment volume
• Channeling: Bypasses biological treatment processes
• Uneven distribution: Diminishes system performance

• Material: Flexible thermoplastic coated reinforced fabric (non-laminated)
• Sealing: Dielectric sealing for watertight enclosures
• Flotation: Logs positioned at surface level
• Ballast: Chain ballast anchored at lagoon bottom
• Optional: Tension cables for reinforcement; field-addable, relocatable flow-through windows

• Cooling ponds (thermal management)
• Settling basins (particle settlement)
• Oxidation ponds (biological treatment)
• Municipal and industrial wastewater lagoons

All baffles are 100% custom-built for each lagoon's dimensions, fluid type, and application.

Yes. AWTT covers are made from food-grade HDPE, and Hexprotect AQUA is available in NSF/ANSI 61 certified, FDA-compliant resin (21 CFR 177.1520) for drinking water contact. The certification is held by the resin; the finished cover assembly is not itself NSF-certified. The material does not leach plasticizers, BPA, or chemical additives, and does not react with chlorine residuals or chloramines.

Yes. AWTT covers have been independently tested and certified free of:

• BPA (Bisphenol A)
• BPS (Bisphenol S)
• BPF (Bisphenol F)
• Phthalates
• PFAS (per- and polyfluoroalkyl substances)

Yes. By blocking greater than 99% of sunlight at maximum coverage, the covers prevent cyanobacteria and algae growth, eliminating:

• Cyanotoxin release (microcystin, cylindrospermopsin, anatoxin-a)
• Increased chlorine demand
• Disinfection byproduct formation
• Annual chemical treatment costs of $50,000-$500,000 depending on reservoir size

Lead time depends on the product and the supplying plant:

Lead time runs from receipt of the down payment, not from the quote date.

Because the deposit is what buys the resin. AWTT purchases polymer specifically for each order; until that purchase is made the order has not entered manufacturing. A PO alone does not start the clock.

Most products have no formal minimum beyond what is economic to ship. Two exceptions:

• Hexprotect MAX R — 9,000 sq ft. The insulation foam is supplied in sealed barrels that begin curing once opened, so a partial barrel cannot be kept for a later run.
• Non-black colours — 10,000 sq ft. See the colour question in Materials & Construction.

If a MAX R requirement falls below the minimum, ask anyway — leftover foam from a recent run can sometimes cover a smaller job.

A 53-foot trailer carries approximately 8,931 sq ft of Hexprotect AQUA or 6,240 sq ft of Rhombo Hexoshield. Freight is charged by the truck, so ordering slightly under a full load means paying for space not used. It is worth checking quantity against the truckload figure before finalising.

Modules ship loose in bulk bags ("super sacks"), two bags per pallet, double-stacked: approximately 450 pieces per bag for Hexprotect and 1,200 pieces per bag for Rhombo. Coverage density is 2.62 Hexprotect tiles per sq ft and 10 Rhombo modules per sq ft.

Yes, with one important distinction:

• Fine-bubble diffused aeration — no meaningful effect. The cover sits undisturbed above it.
• Coarse-bubble aeration — pushes modules apart directly above each diffuser, opening gaps in coverage.

On coarse-bubble systems, either specify Rhombo Hexoshield, which handles the turbulence better, or add extra coverage to compensate for the open area above the diffusers.

Nothing that requires intervention. The cover rests on the exposed bank as the level falls and repositions itself as the level rises. Because the modules are independent there is no sheet to tension, tear, or re-anchor, and no action is needed for large drawdowns.

Match the screening to the module size. The widest dimension of a Hexprotect tile is 7.25 inches; a Rhombo module is 4.5 inches. Any opening a module could pass through should be screened to under 4 inches. A rebar cross-pattern is usually sufficient on steel drain structures; netting secured with cable ties works on plastic pipework.

Modules float freely and repack around fixed obstructions — pumps, sensors, mixers, pipework — without removal. Moving mechanical equipment such as clarifier rake arms or rotating screens requires engineering review before specification; include the equipment details with the quote request.

No. A floating cover is not a work platform and must not be walked on. Where surface access is required, a pathway can be created by stacking tiles, but the cover itself is not rated for foot traffic.