Home Advantage

Sometimes, being popular has disadvantages. In Montgomery County, MD, the area’s good schools, low unemployment rate and proximity to Washington, D.C. and Baltimore have led to an increased population density. To construct enough housing and commercial properties to support those residents, numerous neighborhoods have been built over existing streams, leading to erosion, minor flooding and property damage.

Fortunately, new solutions are being employed, and permeable interlocking concrete pavement (PICP) is one of them. PICP emerged as a solution after a pilot project identified tactics for creating healthier local landscapes conducted about 10 years ago. In response, the County’s Department of Environmental Protection created RainScapes, a pioneering program focused exclusively on reducing stormwater runoff and improving water quality in affected neighborhoods.

Designed to incentivize and implement projects that reduce stormwater runoff, RainScapes offers technical assistance and advice with a rebate program that pays homeowners and commercial building owners to use PICP among other tools. Other RainScapes techniques include tree planting, conservation landscaping, dry well installation, green roof implementation, rain garden design and cistern installation.

One of the most popular aspects of the program has been permeable pavement because the rebate helps offset the high installation costs. For residential projects, the rebate maximum is $2,500 and commercial or multi-family projects can be eligible for a rebate of up to $10,000. To receive a rebate for permeable pavement for residential properties, a homeowner must hire a Montgomery County certified contractor and convert a minimum of 100 sf (9 m2) of hard surface to PICP.

For commercial, multi-family and institutional properties, a minimum of 300 sf (28 m2) must be converted.

The amount of the rebate is meant to cover the cost difference between traditional pavers and permeable pavers, says Dan Somers, who oversees the RainScapes Rewards Rebates. “This is a way to get homeowners to feel more comfortable with permeable pavers,” he says. “When you remove that cost difference, they’re able to compare the options based on factors other than budget.”

In addition to providing the rebate incentive, Mr. Somers visits the project site, talks with homeowners and explains the programs in detail. Sometimes, a homeowner might take on several projects, like installing a rain garden and planting canopy trees, as well as considering permeable pavers.

Although PICP doesn’t make sense for every property, they’re often chosen for residential projects, Mr. Somers says. “Permeable pavers are modular, with a predictable quality, and we have good data on them for the scale of projects that we’re doing, so they come with many advantages.”

Homeowners in the county consider PICP for a number of reasons, says Ann English, RainScapes Program Manager for Montgomery County. Some want to make the property look nicer, while others might want to reduce runoff because they’ve had runoff problems in the past. Some just want to do something for the environment, she adds.

Training Program

When the RainScapes program started, Montgomery County contacted the Interlocking Concrete Pavement Institute (ICPI) for assistance in creating a successful program that would draw interest from homeowners and contractors. The county’s design manual for the RainScapes program was developed with input from ICPI staff who provided technical review of the material.

In addition to the manual, the County developed a professional training course geared toward contractors who want to learn the nuances of a permeable paving system. The daylong class covers stormwater basics, installation processes, troubleshooting and rebate specifics, so they can be more familiar with the program.

Once they complete the course, contractors are included on the County’s “professionals list,” which can be accessed by homeowners and commercial building owners. The list also includes information on how many rebates contractors have garnered, so those perusing the options can determine level of experience with permeable paver projects and RainScapes rebates.

For homeowners and other building owners, the County offers a series of consumer-friendly manuals on the RainScapes website that give more detail about potential projects and show photos of successful installations. For example, on the permeable pavement page, the Department of Environmental Protection includes a slideshow of permeable paver projects, including “before and after” photos that give a homeowner a sense of what installation might include. The website also contains information on how a homeowner can assess a property to determine the best location for a permeable paver project, and actions that can be taken to maintain it after installation.

Strong Results

With over 40 residential projects completed, Ms. English and Mr. Somers have a sense of the program’s effectiveness, finding that the RainScapes projects show significant success in handling stormwater. Although there’s some pressure from outside sources to include porous concrete or other alternatives in the program, RainScapes remains focused on PICP because of its numerous advantages, says Ms. English.

“They’re easier to clean for homeowners, and we feel very comfortable with a system that includes pavers that must be recognized by the ICPI,” she notes. “There’s an extra level of credibility and support there.”

Local contractor Mike Walters, owner of First Impressions Hardscapes in Sandy Spring, MD, installed permeable pavers on about 30 residential properties as part of the RainScapes program. In total, he’s done close to 300 projects with permeable pavers in the county. He shares Ms. English’s opinion that permeable pavers provide several benefits that would be challenging to replicate with other pervious or porous paving materials.

“The pavers are aesthetically pleasing, but what’s genius is the system below them,” he says. “That’s driving demand, because people are looking for new ways to handle water problems on their property, and using a permeable paver system dramatically cuts down on water runoff.” Mr. Walters installed a permeable paver system on his own driveway and uses the captured rainwater to water his lawn.

As an advocate of better stormwater management, Walters believes the RainScapes program could be a boon for any community, city or county as most have too much stormwater runoff. “The program is awesome, there’s great incentive for people to invest in a greener alternative here, and you’re getting an attractive product at a better cost,” he says. “In this situation, everybody wins.”

Additional Resources

To learn more about the Montgomery County RainScapes program, visit


Great Preservation

Across Iowa, cities and towns are using permeable pavement in infrastructure rehabilitation. They are exploiting the multiplier effects (and benefits) that result from combining stormwater management with pavement rehabilitation using permeable interlocking concrete pavement (PICP). These projects not only reduce local flooding and stormwater pollution, they support road rehabilitation and historic preservation.

Three Iowa cities recently completed multimillion dollar PICP projects with local, state and federal government funding. A primary funding source comes from the diversification of Iowa’s State Revolving Fund (SRF). The low-interest loans, normally used for wastewater treatment projects, are now additionally directed toward infrastructure projects that reduce stormwater runoff, specifically flows into wastewater treatment plants and combined sewer overflows (CSOs).

PICP has been deemed an eligible project element for infiltration in projects intended to reduce CSOs. Other municipalities, including those in Washington, Oregon, Michigan, California and Washington, D.C. are conducting similar projects with more on the way.

Green Alley Project: Dubuque

Situated on the Mississippi River and chartered in 1837, Dubuque lays claim to being Iowa’s oldest city. Its location and topography make it prone to damage from stormwater runoff and flooding. In 2011, the city experienced over 13 in. (325 mm) of rainfall in 12 hours, resulting in severe flooding of over 1,300 households. The event was a major impetus for the installation of nine green alleys to reduce flooding and CSOs, which led to planning for another 80 alleys, all built from PICP.

“We’re a very sustainable city, and it’s a mantra that resonates with City staff,” says Jon Dienst, civil engineer for the City of Dubuque. “The pavers were a natural fit for clean water and city design.”

City officials took cues from Chicago, now home to more than 100 green alleys under a program targeting four initiatives:

1. Stormwater management (CSO reduction)

2. Urban heat island reduction

3. Material recycling

4. Energy conservation

Dubuque’s first two alleys were piloted in 2009 using porous asphalt and PICP; funding was through the federal Community Development Block Grant program. “The City council, without even talking about the performance, just liked the look of the concrete pavers in the alleys,” Mr. Dienst recalls of the initial decision.

After the launch, the City decided to take advantage of the state’s low-interest loan funds to borrow $64 million for a major overhaul of Dubuque’s wastewater treatment plant. The alley financing comprised $9.4 million in State Revolving Funds designated by the Iowa Department of Natural Resources for wastewater and clean water projects. The alleys qualified.

The catch: the funding had to be spent within three years. “That’s a lot of alleys,” Mr. Dienst says. Forty-eight alleys will be constructed this year with an additional 25 next summer. The 25 alleys next year will have sewer and water mains and services replaced at City cost with the SRFs used for the alley pavement and stone.

The alleys are roughly 300 ft (90 m) long and 12 and 14 ft (3.6 to 4.2 m) wide. Each costs about $100,000, depending on topography. The City uses modeling software to determine the reservoir capacity and resulting thickness for open-graded aggregate subbase in each alley. A range of rain events are modeled and the subbase thicknesses determined by extensively testing the soil subgrades for infiltration. 

Each alley uses 31/8 in. (80 mm) thick concrete pavers over 2 in. (50 mm) of ASTM No. 8 stone. That sits on a 4 in. (100 mm) base layer of No. 57 stone. Under this layer is

a No. 2 stone reservoir subbase. The project team employed geotextile on the soil subgrade of each alley to help keep the stone clean.

Some of the alleys are next to buildings with foundations over 100 years old. Those installations included new waterproofing to prevent water infiltration. From a cost standpoint, this was well worth the expense, Mr. Dienst says, to prevent water in basements or worse.

“We didn’t have experience in Dubuque,” Mr. Dienst says. “We had to talk with others and learn from their mistakes.” Suppliers and contractors were hard to come by at first, but now are abundant in the area, with pricing around $3.75 to $4/sf ($40 to $43/m2). “It’s almost cheaper to put in the pavers than concrete or asphalt,” he says.

The alleys are being monitored for water quality performance and are expected to reduce nitrates by 25 percent and phosphorous by 60 to 70 percent, achievements supporting the City’s clean water initiative. An 80 percent reduction of stormwater runoff volume is expected as well. Maintenance costs are low, and the City has invested in a vacuum cleaning truck to help in that effort.

Aesthetically, pavers are well suited for a city heavily rooted in its past. “They are historically appropriate,” Mr. Dienst says. “A lot of them are downtown. We are a historic city, recently celebrating 175 years. Historic preservationists are excited about this.”

Permeable Streets: Charles City


About 130 miles (78 km) northwest of Dubuque sits Charles City with a history of flooding and runoff problems. Federal and state funding provided resources to install 27 blocks of PICP in a residential neighborhood slated for street rehabilitation. 

Through the help of now-retired City Administrator Tom Brownlow, Charles City received $3.6 million in 2010 from the American Reinvestment and Recovery Act to install the initial phase of the project. At $2 million, phase two utilized Iowa’s State Revolving Fund and 30 percent forgiveness of the eligible costs, essentially paying for the paving portion of the project. The remaining funding paid for sanitary, sewer and water line improvements.

Both projects involved city street renovations with the second phase having learned several lessons from the first. “The first time was a hard sell,” recalls Dirk Uetz, Charles City’s superintendent of streets. “People were a lot more open-minded after they had seen the first project.”

The City commissioned the Conservation Design Forum (CDF) to design the permeable streets. The designers modeled the system to capture runoff from streets, yards and alleys and infiltrate the runoff. Peak discharges for the 10-year storm were reduced by more than 90 percent, according to CDF. This reduction prevented the necessity and expense of upsizing many existing storm sewers. The design took advantage of the sandy soil subgrade by infiltrating much of the runoff rather than directing it to inlets and into storm sewers. Also, the permeable streets were narrowed by 5 ft (1.5 m), thereby increasing the tree lawns and the graceful appearance of the old neighborhood.

Phase one spanned 16 blocks and included permeable areas at intersection corners covered with large stones surrounding raised beehive intakes. These areas ultimately proved difficult for the local homeowners and for the city’s maintenance staff to clean. They also presented some risk to children playing nearby. The phase two design of six-and-a-half additional blocks reverted to regular storm drainage intakes, which were easier to maintain and presented no risks to children. Additionally, phase one used slightly depressed retention areas with amended soils in the tree lawns behind the curbs. These proved inconvenient for pedestrians and were replaced by an improved, raised design in the second phase.

While response to the new streets has been positive, the real success lies in the runoff reduction, Mr. Uetz says. “If we have a heavy rain now, you don’t see any water going down to the river,” he says. “In phase one, we opened the hydrants onto the street and let the water run. The spectators couldn’t believe it.”

Downtown Restoration: West Union


A farming hamlet about an hour’s drive west of Dubuque, West Union had its share of stormwater flooding problems including contamination of nearby Charles Stream. Moreover, its aged and worn downtown needed an update.

West Union took the opportunity to implement its Clean Green Climate Action Plan in six downtown blocks. The U.S. National Renewable Energy Laboratory weighed in on the project, which included energy conservation, greenhouse gas reduction and pedestrian infrastructure improvements. Geothermal heating and cooling systems were also built as an incentive for businesses to fill the downtown storefront vacancies, and these systems included snowmelt capabilities.

Completed in 2013, the project totaled $10 million and used state stimulus money, funding from the Iowa Department of Transportation, the U.S. Department of Energy, the Environmental Protection Agency and others. Both the Iowa Department of Agriculture and Land Stewardship and Watershed Improvement Review Board contributed $500,000 each toward the project, with the majority going toward PICP.

“Prior to the project, there was nothing for storm drainage in the downtown area,” says Jon Biederman, branch manager for Fehr Graham, an engineering and environmental firm that worked on the project design. “We were looking for a way to clean and cool water [before it runs] into Charles Stream. An easy way to accomplish this was with permeable pavers.”

The infiltration system filters runoff through an open-graded stone base to cool it and clean it, accomplishing both goals at once. It also slowed the stormwater runoff substantially. “It can take a few days versus a few minutes,” Mr. Biederman says.

West Union’s PICP design differed from the norm. While typical PICP installations include a stone subbase storage layer no more than 1- to 2-ft (0.3- to 0.6-m) thick, West Union needed much more storage. In most areas, the subbase is 3- to 5-ft (0.9 – to 1.5-m) thick to store, infiltrate water into the clay soil subgrade, and release any excess slowly to the downstream waterway. The subbase storage layer was topped with a 6-in (150-mm) layer of clean, crushed stone as a base for the bedding layer of 1½ to 2 in. (40 to 50 mm) limestone chips.

The concrete pavers rest on this bedding layer, their joints filled with small permeable aggregate.

The clay soil subgrade demonstrated that PICP can be designed to infiltrate into low infiltration soils. The City purchased a vacuum truck for the main thoroughfare and a smaller unit for the sidewalks and to clean the joints twice a year. Ultimately, the design met the project goals for infrastructure restoration, positive environmental impacts and historic preservation.

The street previously had been paved with asphalt over brick pavers placed in 1914. The contractor retrieved the old bricks and incorporated them into decorative strips in the intersection centers. They are installed on the same stone base as the concrete pavers with permeable, stone-filled joints.

“We’ve had very positive responses,” Mr. Biederman says, noting the initial skepticism of the local residents and business owners who were not initially keen on the change. “They look good.”

As demonstrated by West Union, as well as by Charles City and Dubuque, Iowa presents some groundbreaking examples of creatively funding infrastructure renovation projects with PICP.

Additional Resources

ICPI Permeable Pavement Resources

Permeable Interlocking Concrete Pavement Design Manual

ICPI Permeable Pavement Resources:



Investing in Efficiency

Bill Gardocki, owner of Interstate Landscape Company in Londonderry, New Hampshire, brings his 40 years in the landscape business and over 10 years of ICPI and NCMA teaching experience to this year’s Hardscape North America show in two classes covering efficiency. A hands-on class, Tools for Paver Installation Efficiency, covers efficient paver installation, while an indoor class, Increasing Efficiency on the Hardscape Jobsite, covers efficiency from the initial quote to job site preparation and on-site techniques. The classes offer information for contractors new to the business or experienced ones looking to learn more.

The Right Tools

Mr. Gardocki’s hands-on class demonstrates the latest tools and techniques that expert paver installers use, from simple hand tools to big, complex vehicles. Using more efficient tools reduces labor costs and accelerates job completion without compromising quality.

All of this creates more time for more projects and more income. Mr. Gardocki stresses this in his classes, as some contractors often are hesitant to buy new tools due to sticker shock.

“I can’t tell you how many guys tell me that they can’t afford the extra $10,000 for a higher load-capacity skid steer,” says Mr. Gardocki. With their lower load-capacity machine, they have to remove two or three layers of pavers from each pallet to be able to lift and move each around the job site. So I get them thinking about the two or three layers of pavers they removed from every single pallet and extrapolate that out to how many times a year that’s done, and the total amount of time spent. Beside this, I ask them to consider all the little things they think don’t waste time—they think it’s just a part of what they do—and then add up all that time they waste by using inefficient equipment. They think, ‘it takes just five minutes longer,’ but they’re doing it hundreds of times a week and thousands of times a year. It adds up to wasted time and money.”

Mr. Gardocki still remembers coming home from an ICPI class he took 17 years ago and throwing away all of his compaction equipment and completely changing the way his company worked, because it was inefficient. “It was an instant change in our business,” he says. “We were able to extend our warranties. Most guys will offer a one-year, maybe two-year warranty, when you should easily be offering upwards of a five-year warranty.”

“Compaction equipment is probably the most important equipment in this industry and guys just don’t look at it as an investment for better compaction and warranty sales, they look at it only as a necessity,” he says. “In my classes, I try to show them how the compaction equipment pays for itself very quickly over time, more quickly than any other piece of equipment in our industry.”

Mr. Gardocki sees HNA as a great way to find out about new tools that could help make your business more efficient. That’s why he brings some of his employees there to investigate new tools and techniques. “I always tell my guys: ‘If you see something that’s going to make your job easier and less stressful on your body, let me know,’” he says. “Because I’ve invested a lot in my foremen and I want them to stay healthy as long as possible.”

A Solid Plan

While planning is hugely important for efficient, successful contractors, Mr. Gardocki understands why it is often one of the more overlooked aspects of the business. “Let’s face it, most contractors have never taken a class in business,” he says. “The last thing they want to do is come home at night and sit down and plan things out for the next day, but that’s the way it really needs to be done.”

Although planning may not be the most desirable activity for contractors, Mr. Gardocki emphasizes just how important it is by pointing to a statistic from a book by Charles Vander Kooi that reads, “One hour of planning saves eight hours in the field.” For contractors looking to save money, Mr. Gardocki says the first thing they should look into is more focused planning.

He ascribes much of his own success to his ability to plan well. “In my town we’ve been by far the longest running landscape business. It’s not because we’re any better at installation than anyone else—it’s because we’re better at running the office than anyone else,” he says.

Mr. Gardocki explains that finishing a job with a healthy profit margin requires careful planning. In his business, he bids jobs based on the hours they take to complete, rather than on square footage or another measurement. To do this, he divides tasks his employees do into 18 labor functions, which he can then benchmark against previous jobs to come up with the right bid.

“You need to track [this data] so that in the future you’re bidding accurately and understanding how long it’s taking your crews to do certain tasks,” he says. “The record-keeping really pays off in the long run because you may be bidding too high based on tasks that aren’t taking you as long as you think. All the guys I know that are very successful track their hours.”

While some contractors will bid on contracts using square foot pricing as their basis—as opposed to tracking labor hours—Mr. Gardocki says this is a mistake because no two sites are the same.

“There’s no situation where it’s better to do it by square foot,” he says. “One key thing for us is access to the site. You could have two houses right next to each other that both want a 400-square-foot patio, but if one has a fence around the whole backyard and you have to take down the fence and drive across a beautiful lawn and rehab the lawn, the job will cost more. It’s impossible to charge by the square foot and understand whether you’re making any money or not.”

Keeping records of your jobs is helpful for all contractors, but Mr. Gardocki says it’s especially important for people who are new to the trade.

“For the new guys, they have to know and understand that one crew might not be as quick and efficient as another crew,” he says. “So it really comes down to their foremen and understanding the strengths and weaknesses of their foremen. Can their foreman handle three guys and be really efficient or is he the kind of guy that can only handle one other guy with him? It’s all in the record-keeping and as long as you’re keeping track, it makes [answering those questions] much, much easier.”


Additional Resources

To learn more about Bill Gardocki’s classes at the 2014 HNA show and to register, visit

The Complete Business Manual for Concrete Paver Contractors


Charity Car Wash Bans

An article in a recent Washington Post reported that a city in Northern Virginia is banning ad hoc fundraiser car washes sponsored by charities. The article noted such bans are common in western states, but new to the nation’s capitol area. The reason cited, not surprisingly, is uncontrolled water pollution entering storm drains, streams, rivers and ultimately the Chesapeake Bay.

However, such regulations send an inadvertent blow against volunteer groups wanting to raise money for good causes. Their fundraising options are reduced to passive and possibly financially riskier activities such as yard and bake sales. 

There’s another side to these types of car washes. Where are they are held? Often on commercial parking lots such as a bank, coffee shop, gas station or a fast food restaurant. Business owners must like the attention drawn to their businesses as well as the civic support message. Some water exchanged for publicity? Not a bad public relations deal. So with regulations closing down ad hoc car washes, businesses that host them lose as well.

Instead of nixing a viable revenue source for often financially-strapped volunteer organizations, why couldn’t regulations allow such car washes only on permeable pavement? Granted, there aren’t a lot of commercial properties with permeable pavement right now, especially on highly visible sites conducive to attracting customers.

But there is hope. A growing number of municipalities are providing cash rebates to residential and commercial property owners to install permeable pavements. Municipalities realize that it might be less expensive to revert the earth’s surface from impervious back to permeable to break the vicious financial cycle of upsizing storm sewer pipes.

Montgomery County, MD, (pop. 1 million) is one such place providing financial incentives to install permeable interlocking concrete pavement (PICP) in residential driveways and commercial parking lots. Called RainScapes Rewards, the financial incentives aren’t huge, but they are a positive start. This issue features an article on what the County and its residents have accomplished.

Stormwater utilities abound across the U.S. and Canada where property owners pay their municipality a fee—like trash and sanitary sewage—to carry away and dispose of stormwater. The fee is often paid with the water and sewer bill. About half of the stormwater utilities offer as much as a 50 percent reduction in fees if permeable pavement or other practices are installed to reduce the amount of runoff the municipality must transport via its storm drainage system.

Beyond stormwater utility fees, what if municipalities offered property tax relief for installing permeable pavement for the purpose of supporting charitable organizations? Relief could be offered for the permeable area for a period of years or as long as the permeable pavement exists. A more generous approach might include tax relief on the impervious surface(s) draining into it, as well as on the permeable pavement. From the municipal perspective, they would want to know the extent to which their drainage system benefits by giving up a few to several thousand dollars annually in tax revenue. For cities with minor flooding areas, adjacent high-value rivers and lakes, or combined sewer overflows, it might be worth it. 

If municipalities went this route, or even the more benign stormwater utility fee route, they could incentivize car washes on permeable pavements. Example: install PICP, host 10 car washes annually and receive a property tax or utility fee break. Wouldn’t that send a positive signal to volunteer organizations? Many of these organizations already do public sector-type activities, saving municipalities time and money. Keeping such organizations going with a range of revenue options while protecting the environment is good for everyone.