Lancaster's Green Infrastructure Design Manual says porous pavement surfaces include, but are not limited to, porous asphalt, porous concrete, pavers and turf, and that the City welcomes innovative technologies if proprietary products can be shown to meet the manual's intent. A permeable resin-bound section on an open-graded stone bed with Rock Crete or another permeable base on top can be proposed on that basis. Over an existing slab, it does nothing for the City's volume rule.
The city has made stormwater part of almost every exterior project. Any added, removed or reconstructed impervious surface needs a permit, and most runoff here enters a combined sewer that overflows to the Conestoga River. Fee credits and a residential grant program reward owners who manage water on site.
A permit for almost everything, and a 1.25-inch removal standard
Lancaster requires a stormwater management permit when any amount of impervious surface is added, removed or reconstructed, or any earth is disturbed. Very small projects involve under 100 square feet of new or reconstructed impervious surface, small projects 100 to 1,000, and large projects 1,000 square feet or more, or 5,000 square feet or more of earth disturbance. Small and large projects must permanently remove at least the first 1.25 inches of runoff from new impervious surface through infiltration, reuse, evaporation or transpiration. Large projects must also show no increase in runoff volume up to the 2-year, 24-hour storm, unless they cut impervious area by 25% or more on a site that is already at least 25% impervious.
Porous pavement that takes no run-on and meets the manual's disconnection criteria is not treated as impervious for volume control, though it still counts as impervious for zoning and for setting the project type. Disconnected systems of 500 square feet or more need infiltration testing. Porous pavement that accepts runoff from other areas is treated as a subsurface bed with a porous top and calculated as impervious.
Carbonate bedrock, the Conestoga and a combined system
The manual is direct about geology: limestone and dolomite are prolific throughout the city and can form sinkholes, caves and depressions. It defines active karst as known features within a quarter mile of the site, or a high potential for them, and outside those areas does not treat carbonate geology as a general constraint. In active karst, infiltration may still be feasible, but stormwater should not be overly concentrated, so loading ratios and bed layout matter.
Most runoff enters the combined sewer, while the city's three watersheds, the Conestoga River, Little Conestoga Creek and Mill Creek, carry the rest toward the Chesapeake Bay. Rate control varies by watershed under the Act 167-based ordinance, and BMPs on the combined system that cannot drain by infiltration may use a slow-release outlet. For a permeable section, design for full infiltration where soils allow. Freeze-thaw and road salt call for vacuum cleaning and no sand.
Where it fits in Lancaster
- Rowhouse rear yards and alley parking pads: small projects that must remove the first 1.25 inches of new runoff on tight lots.
- Homeowner retrofits: the Stormwater Residential Grant Program funds small green infrastructure such as permeable pavers, rain gardens and dry wells.
- Church, school and nonprofit lots: large impervious areas where a credited facility can reduce the fee by up to 50%.
- Downtown courtyards and plazas: redevelopment sites in the combined sewer area, where pedestrian surfaces can sit over infiltration beds.
Permits from the Bureau of Stormwater Management
The Bureau of Stormwater Management in the Department of Public Works reviews permit applications and designs, inspects installations, and handles fee credits and appeals. The manual's material standards for porous asphalt and porous concrete follow PennDOT Publication 408, so expect a resin-bound proposal to be judged against the porous pavement section's performance intent rather than a named specification. Bring infiltration rates, structural data and a maintenance plan.
Resin Rock supplies binder, stone blends, trims and the Rock Crete permeable sub-base, with technical data sheets for that review. We do not install. Find an installer to be matched with an approved installer, usually within 24 hours, or see Pennsylvania installer training.
Before you specify permeable resin-bound in Lancaster
- Pick the right permit application, very small, small or large, by square feet of new or reconstructed impervious surface and of earth disturbance.
- Size storage to remove the first 1.25 inches of runoff from new impervious surface.
- Check for known karst features within a quarter mile of the site.
- Run infiltration tests for disconnected porous surfaces of 500 square feet or more.
- Bring product data showing the resin-bound section meets the manual's porous pavement intent.
Common questions about permeable resin-bound in Lancaster
Will a resin-bound driveway lower my Lancaster stormwater fee?
Not by itself. The fee's definition of impervious surface includes any area used by vehicles, regardless of surface type or material, so a driveway or parking area stays in the calculation. Fee credits of up to 50% depend on the type of facility and the share of impervious area it treats, and they need a separate application.
Do I need a permit to replace a patio?
Yes. Lancaster requires a stormwater permit whenever impervious surface is added, removed or reconstructed, or earth is disturbed. Under 100 square feet you use the Very Small Project application, which does not require volume control; from 100 square feet up, the first 1.25 inches of runoff from new impervious surface must be removed.
Is the residential grant available for resin-bound surfaces?
The Stormwater Residential Grant Program funds small green infrastructure on homes, and the City names permeable pavers, rain gardens and dry wells as examples. Resin-bound is not named, so ask the Bureau of Stormwater Management before applying. A design on an open-graded infiltration bed, with test results, is the version most likely to be considered.
Official sources for Lancaster
- City of Lancaster stormwater permits (very small, small, large)
- City of Lancaster Green Infrastructure Design Manual (updated June 2024)
- City of Lancaster stormwater management fee and credit program
- City of Lancaster stormwater grants and incentives
Local rules change. We last checked these sources in October 2026. Confirm current requirements with the reviewing agency before you design, and treat this page as a starting point, not engineering or permitting advice.