Frequently Asked Questions - Commercial

Permeable interlocking concrete pavement (PICP) consists of manufactured concrete units that reduce Seattle WA PICPSeattle WA PICPstormwater runoff volume, rate, and pollutants. The impervious units are designed with small openings that create permeable joints. The openings typically comprise 5% to 15% of the paver surface area and are filled with highly permeable, small-sized aggregates. The joints allow stormwater to enter a crushed stone aggregate bedding layer and base that supports the pavers while providing storage and runoff treatment. PICPs are highly attractive, durable, easily repaired, require low maintenance, and can withstand heavy vehicle loads. The picture shows installed pavers in a Seattle, Washington residential neighborhood. PICP significantly reduces the total amount of impervious surface and runoff.