Paving the way

Permeable pavers reduce the amount of debris and pollutants flowing into a storm sewer system and other bodies of water. Vast Enterprises, Fred Adams Paving.

Most environmental officials report that stormwater runoff is one of the more significant factors responsible for polluting U.S. waters today.

“The number one reason for the increasing number of beach closures due to contamination is stormwater runoff,” says Kevin Earley, director of commercial sales for Nicolock Paving Stones in Long Island, N.Y. Stormwater picks up oils, chemicals, fertilizers, sediments, dirt and debris and many other pollutants flowing into a storm sewer system or directly to a lake, stream, river, wetland or coastal water. Anything that enters a storm sewer system can be discharged untreated into the water bodies used for swimming, fishing and providing drinking water.

But there is an effective solution to deter pollution from hitting waterways: installing permeable pavers.

Take the case of Lindenhurst Memorial Library’s new parking lot: “If it wasn’t for the permeable pavers system we installed in 2009, most of the stormwater hitting the parking lot for the past couple years would have wound up in the Great South Bay through the sewer system,” says Earley.

Another case study Earley is particularly proud of is the Bel Air, Md., historic town park project where his company installed another permeable interlocking concrete pavement (PICP) system that same year. All stormwater runoff was eliminated with the system while the pavers themselves retained the park’s historic integrity.

Just like conventional paving systems, PICP systems create a strong, durable surface capable of carrying heavy loads. What makes them pervious is not the concrete itself, but the system of wide joints between the pavers set on a deep base of aggregate that allows the water to filter through. Contaminants are contained and excess water is absorbed into the subgrade below the surface.

Earley is a member of the American Society of Civil Engineers Standards Committee on Interlocking Concrete Pavements and the LID Task Committee on Permeable Pavements. He touts the numerous benefits of installing PICP systems. “There will continue to be increasing restrictions on stormwater runoff for both residential and commercial properties in most major cities,” he says. “Increasingly, property owners are paying for water leaving their premises.”

Cost savings is now also an incentive for customers. For less than the additional cost of a flexible pervious paved parking lot, developers quite often discover they can reduce construction costs by eliminating Environmental Protection Agency’s Phase II Rule, which requires drainage and retention ponds that take up valuable land space and are costly to install.

Another incentive is the increasing focus on PICPs for inclusion in the LEED rating system for new commercial construction. Stormwater containment is a high priority for LEED when assessing a site’s environmental performance, responsible for scoring many valuable points.

The advantages of PICP systems make it a solution not only for the environment, but for business growth as well.

 The author is a freelance writer based in Akron, Ohio.

Did you miss the hardscape supplement in our February issue? Don’t worry, you can find it on our website. Visit www.lawnandlandscape.com, click on current issue and February 2012.
 

Saving with paving

Whether a large residential patio or long strip mall walkway, hardscape projects can be tedious and time consuming to install. But they don’t always have to be.

At the 2011 Hardscape North America’s Outdoor Arena, Chuck Taylor, a national hardscape adviser, showed attendees how to use mechanical paver installation machines, placing nearly 2,600 square feet of concrete pavers.

“The demonstration is designed to show labor savings upwards of 60 percent over manually installed pavers,” Taylor says.

Mechanical installations increases the capacity of a contractor using manually-installed labor to increase paver installations per day to quantities that range from 3,000-10,000 square feet depending upon such factors as accessibility, flow of materials, laying face width and the size of the paver layer.

“With these machines, a crew of three can set 100 pallets a day, or approximately 7,800 square feet of paving stone,” Taylor says. “Without the machine, the same crew could only set approximately 1,000 square feet.”

Based in Atlanta, Taylor has 35 years of experience as a designer/builder for segmental paver systems. For the past 15 years, he served as a consultant to engineers, municipalities and stormwater designers for segmental construction of permeable pavement systems.

“For the past 30 years, there has been an increased market demand for paver-style installation,” Taylor says. “And now that many municipalities are restricting water runoff on both commercial and residential properties, permeable interlocking pavers are increasing the demand even more.”

The machines are capable of picking up an entire layer of pavers (9-14 square feet at a time) off a pallet, gripping them tightly and then placing the entire group into position atop the setting bed.

Just how fast is this task performed? With a good operator, the machines can put down an entire pallet of pavers within a few minutes. About every 12 seconds, the machine places another course of pavers.

To use the machines, block manufacturers must produce the blocks with molds and stack them in a pre-set pattern. The machines then clamp down, lift and place the blocks one at a time.

The machines articulate at two different points with one wheel following the other, allowing it to turn in a perfect circle with no side scuff while keeping the blocks extremely stable.

“Using a machine to lay pavers doesn’t automatically mean you are going to save money on a project,” Taylor says.

He cites the many factors to take into account include, the size of the project, number in the crew, efficiency of the crew and amount of material you handle in a day. Paver machines can run as high as $60,000 to purchase, so most are contracted for individual jobs. For those willing to make the investment, there are opportunities.

Although you can install either ICPs or PICPs with machines, the demonstration featured PICP green pavers that were part of a sustainable pavement system designed to improve the ecological impact of a site. These types of pavement systems provide a green solution and contribute to the LEED process for sustainable site credits.

– Tom Crain

Hardscape North America again will coincide with GIE+EXPO in 2012 in Louisville, Ky. The show will take place Oct. 24-26.