GRASSY PAVERS™ & the Environment
Recycled HDPE
(vs 95%+ for impervious)
Percolation Rate
Multiple Categories
Non-Toxic HDPE
Stormwater Management
The Problem with Impervious Surfaces
Concrete and asphalt are nearly completely impervious — they have runoff coefficients of 95% or higher, meaning that 95 cents of every dollar of rainfall becomes surface runoff. This runoff carries pollutants, sediment, and debris into storm drains and waterways, overwhelming municipal infrastructure and degrading water quality.
The GRASSY PAVERS™ Difference
- Runoff coefficient of just 1.2% — nearly all rainfall percolates directly through the system
- Percolation rate of 8–10 inches per hour — handles the heaviest precipitation events without surface ponding
- Groundwater recharge — water returns to the aquifer rather than being lost to storm drain systems
- Eliminates retention ponds in many applications, saving significant land area and construction cost
- Natural pollutant filtration — soil and gravel layers filter sediment and contaminants as water percolates through
- EPA stormwater compliance — recognized as a Best Management Practice (BMP) for MS4 permit compliance and local stormwater ordinances
Property developers, municipalities, and engineers specify GRASSY PAVERS™ specifically to meet stormwater management requirements without the cost and land-use impact of traditional retention and detention infrastructure.
How Water Moves Through the System
The GRASSY PAVERS™ system is engineered to move water efficiently from the surface to the native soil below:
- Rainfall lands on grass-filled or aggregate-filled cells and immediately begins moving downward
- Water passes through the open base and perimeter drainage channels of the HDPE panel
- Water percolates through the sand leveling layer
- Water enters the compacted gravel base — this layer stores water temporarily during heavy rain events
- Water passes through the geotextile fabric into the native subsoil for groundwater recharge
The result: stormwater stays on your property and returns to the water table, rather than becoming a liability on neighboring properties or in municipal infrastructure.
LEED Eligibility
GRASSY PAVERS™ are LEED point-eligible under the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) rating system. Architects, engineers, developers, and project managers specify GRASSY PAVERS™ when pursuing LEED certification for commercial, institutional, and residential projects.
Applicable LEED Credit Categories
- Sustainable Sites — Stormwater Design (Quantity and Quality): Permeable paving that reduces runoff volume and improves water quality qualifies for stormwater management credits.
- Sustainable Sites — Heat Island Effect (Non-Roof): Green, vegetated surfaces have a significantly lower solar reflectance index than dark asphalt, reducing heat island contribution.
- Materials & Resources — Recycled Content: GRASSY PAVERS™ contain a minimum of 97% post-consumer recycled content, qualifying for recycled materials credits.
- Innovation in Design: Unique environmental performance characteristics may qualify for innovation credits depending on project specifics.
Consult your LEED project administrator or sustainability consultant for credit applicability specific to your project. GRASSY PAVERS™ can provide product data sheets, recycled content certifications, and stormwater performance data to support your LEED submittal.
The Recycled HDPE Story
What is Regrind?
When post-consumer plastic products (milk jugs, detergent bottles, industrial containers) are collected for recycling, they are sorted, cleaned, shredded, and melted into what the industry calls regrind — a raw polymer feedstock made entirely from recovered plastic waste. This regrind is then used as the primary raw material for manufacturing GRASSY PAVERS™ panels.
97% Post-Consumer Recycled Content
Each GRASSY PAVERS™ panel contains a minimum of 97% post-consumer recycled High Density Polyethylene (HDPE). This means:
- Plastic waste is diverted from landfills and given a second life as a high-performance structural product
- Significantly lower embodied carbon compared to virgin plastic or concrete manufacturing
- No virgin petroleum feedstocks required for panel production
- The HDPE material is non-toxic and non-leaching — it does not release pollutants into soil or groundwater
- HDPE is inherently UV-stabilized and does not degrade under normal outdoor conditions
Carbon Footprint vs. Alternative Paving
The production of GRASSY PAVERS™ from recycled HDPE generates a fraction of the CO₂ emissions associated with manufacturing concrete or asphalt. Additionally, the permeable design eliminates the need for retention pond construction, detention structures, and associated piping — infrastructure that carries its own significant carbon cost. The full lifecycle environmental profile of GRASSY PAVERS™ compares very favorably to traditional solid paving solutions.
Environmental Comparison
| Factor | GRASSY PAVERS™ | Concrete | Asphalt |
|---|---|---|---|
| Runoff Coefficient | ~1.2% | ~95% | ~98% |
| Stormwater Percolation | 8–10 inches/hr | None | None |
| Groundwater Recharge | Yes | No | No |
| Retention Pond Required | Usually No | Often Yes | Often Yes |
| Heat Island Contribution | Very Low (vegetated) | Moderate–High | Very High |
| Recycled Content | 97% post-consumer | Minimal | Some recycled aggregate possible |
| Toxin/Leachate Risk | None — non-toxic HDPE | Minimal | PAH leaching risk |
| LEED Eligible | Yes — multiple categories | Limited | No |
| EPA Stormwater BMP | Recognized BMP | Not applicable | Not applicable |