Parish Parking Goes Green: Safety & Icing Issues Cured With Permeable Pavers

By Bruce H. Soileau, Consultant to Pavestone Company

Permeable pavers are an eco-friendly alternative to asphalt or concrete that help reduce pollutant runoff, and has two to three times the life cycle of asphalt. Water filters between the pavers, through a stone-bedding layer, then directly into the ground, recharging area groundwater. Images courtesy of Pavestone Company

The St. Augustine Catholic Church project in Brighton, Colorado consisted of a large parking area of 64,000 square feet, installed with the use of Optimus mechanical paver laying equipment.

As the existing storm sewer infrastructure in Brighton exceeded capacity, the city encouraged church officials to consider alternative designs and advocated a permeable parking structure.

Because permeable pavements are not yet in wide use, they require special planning and expertise to install. It is not possible to retrofit paved areas with permeable surfaces without re-engineering all substrate and fill materials. It is recommended that a qualified civil engineer with knowledge in hydrology and hydraulics be consulted for applications using permeable interlocking concrete pavement to ensure desired results.

The Challenges

St. Augustine's Parish began in 1887 with the collaboration of Bishop Machebeuf, William Howlett and the assistance of 12 area families. Originally, the parish was a quaint brick building with a wooden steeple. Since then, the parish has expanded into a majestic facility with over 800 families attending Sunday services.

With such an increase, it became evident additional parking was required. Not only must the site accommodate the parishioners, but it also needed to complement the aesthetics of the church itself. In addition, a major concern was safety and the possibility of ice forming in low spots and potholes in asphalt.

When asked about recommended slope on a project, Joe Hagel, project manager, said, ''Permeable or porous pavements should not exceed 5 percent slope for maximum infiltration, so they require greater initial site evaluation and design effort compared to traditional concrete paver installations.''

The Pavers

St. Augustine's reviewed a variety of permeable and porous pavement systems before choosing Pavestone Eco-Priora. Coupling the front end costs with life-cost analysis, the church decided Eco pavers had the better package according to Ken Anderson, business administrator for St. Augustine Catholic Church. Furthermore, they opted to utilize Pavestone's new Platinum series, which added additional vibrancy and greater color variation.

Permeable concrete paving stones have been used in Colorado for a number of years. In areas that experience large stormwater volume, permeable paving stones help control runoff, mitigate storm surge and improve water quality.

The unique Eco-Priora joint profile allows surface water to infiltrate into the pavement and its sub-layers. With initial permeability average flow rates of over 100 inches per hour, the Eco-Priora product will still meet the majority of current stormwater management plans.

While permeable paver systems may incur a higher cost in the initial stages of installation, the overall costs will even out when you compare it to concrete or asphalt paving. Unlike like other types of pavers, permeable pavers will reduce the installation and material costs of piping for underground drainage purposes and other storm water systems.

The majority of the main parking area was installed mechanically. In mechanized paver installation, specialized paver installation equipment speeds construction time by installing approximately one square yard (one square meter) of pavers at a time in rapid succession, which dramatically reduced installation time and labor costs when compared with hand lay.

Site Guidelines

Joe Hagel, project manager with Continental Hardscape Systems, installed the permeable pavers on this project. He warned, ''When bidding on projects using permeable pavers, it's critical that you obtain bids from paver contractors that are experienced in permeable paver installation. There is a big difference in how the subbase, base, bedding and joint fill is installed compared to traditional pavers. If you do not follow the construction guidelines precisely for permeable pavers, your site will not drain properly.''

Conclusion

Permeable pavers have provided the church with the results they were looking for. The Platinum Eco-Priora is not only lovely but also very functional, ecologically friendly with the benefit of addressing icing. If deicing is required, aggregate layers within the permeable paver base acts as a filter, cleansing the infiltration and reducing possible contaminates.