NEWS

Options Pouring in for Pervious Pavement Care

In the Pacific Northwest, the last decade has seen a dramatic evolution in pervious pavement systems as communities stare down the threat of polluted run-off affecting the region’s waterways. From Seattle’s first pervious concrete roadway in 2005, to the more frequent presence of porous systems in the public right of way and in private development, this multi-purpose infrastructure is helping to relieve a huge burden on our region's ecological health.

Care of these facilities is not only vital to their function and longevity, but with so many systems in place, and more coming online, it becomes vital to the health of the community and environment. These systems must be adequately maintained to provide both stormwater and mobility functions.

So what is the new normal for roadway maintenance when your pavement is porous? Traditional methods don't exactly do the trick, but that's not keeping the equipment suppliers from getting in on the game. A business opportunity is at hand, and fortunately these green pavement systems are benefiting from the maintenance sector's race to be first in line with the newest and best piece of cleaning equipment. Ten years ago, there were few companies advertising cleaning for pervious pavements. Agencies tried different techniques but there was little demand to clean the systems. Now you can barely throw a permeable paver without hitting a manufacturer willing to show off the newest innovation in porous pavement care! Well that's a bit of an exaggeration, but the developments have been pretty fantastic!

The 100-year-old Elgin Sweeper Company is participating in research programs in order to better understand the maintenance requirements of pervious pavement systems. Bunyan Springs, a company "dedicated to the continued advancement and development of pervious concrete technology" has in recent years developed the Bunyan Infiltration Restoration Device (BIRD) which combines a push-behind vacuum innovation with a conventional roadway vacuum truck. And Ben's Cleaner Sales Inc., Triverus and the Seattle Pump and Equipment Company demonstrated their push behind vacuum technology during a demonstration on the pervious concrete paths and parking area at Greenwood Park and Federal Way.

Typically these pavement systems, which include pervious concrete, porous asphalt, and a whole smattering of proprietary permeable pavers have design infiltration rates of hundreds, sometimes thousands of inches per hour (a recent market addition which bucks this trend is the KlorostoneTM ceramic paver with a design infiltration rate of 4in/hr.) A few years after placement, the infiltration rate of these systems will decrease significantly due to leaf litter debris or sediment build up. Several years after installation, and with no maintenance, the infiltration rate of Seattle's first pervious concrete roadway dropped from over 700in/hr down to 9in/hr. And while this seems dramatic, keep in mind that our heaviest rain events in the Seattle area shower us with 4 inches in a 24 hour period. With semi-annual maintenance, a properly designed porous pavement can be expected to retain sufficient drainage capacity and structural integrity to do the infrastructure heavy lifting it's designed to do.

Not only are we seeing development in the field of maintenance equipment but more and more we find answers to the questions of "what", "when" and "how" to care for these systems. The National Ready Mixed Association (NRMCA) Provides guidelines for pervious concrete maintenance in the "Pervious Concrete Pavement Maintenance and Operations Guide". From state and city, to project-level, agencies have developed their own guidance document including the City of Bellevue and SHA High Point. And even more exciting is the research underway that may take the guesswork out of scheduling maintenance crews. At the 2015 International Low Impact Development Conference in Houston Texas, ORISE postdoctoral Fellow Robert A. Brown presented results of an ongoing study that measures the infiltration reduction of the surface from beneath the pavement, a monitoring system that results in a truly needs based maintenance schedule.

As manufacturers, suppliers, research institutes, and courageous agencies continue to collect the data, innovate the equipment, and inform the community, we can expect adoption of these porous pavement systems to become commonplace. In our region, this is good news for the Puget Sound and good news for the community.


by Lolly Kunkler

Looping Public Health into Yesler Terrace's Streetscapes

Located at intersections and along a continuous loop, activity zones like the one shown in this schematic plan, will provide residents with opportunities to recreate while exploring their neighborhood and contributing to vibrant street life.

Located at intersections and along a continuous loop, activity zones like the one shown in this schematic plan, will provide residents with opportunities to recreate while exploring their neighborhood and contributing to vibrant street life.

As designers and planners continue to recognize the health impacts that our built environment has on human populations, new strategies are being deployed to create places where the "healthy choice is the easy choice." This is particularly important for communities where, due to socioeconomic circumstances, the public health odds are already stacked against residents. In Seattle, SvR and the rest of the design and development team behind Seattle Housing Authority's (SHA's) Yesler Terrace redevelopment were keenly aware of these challenges, and promoted "healthy eating and active living (HEAL)" opportunities throughout the design process. 

In early discussions with SHA and the design team, nonprofit organizations and public health officials discussed Yesler Terrace’s cultural diversity, affordability, and high populations of senior and child residents, emphasizing the importance of active spaces to help combat health issues like obesity and diabetes. All stakeholders agreed that the existing parks’ sizes and programming did not meet the needs of the anticipated population of the neighborhood. The Green Street Loop, a 1/2-mile circuit that links three pocket parks to a larger neighborhood park, helps fill this gap by creating a visible and cohesive pathway to neighborhood destinations. The Loop also became an important platform for meeting the neighborhoods' public health goals.

Eight activity zones are identified in gold stars along the 1/2-mile Green Street Loop (in green) at Yesler Terrace.

Eight activity zones are identified in gold stars along the 1/2-mile Green Street Loop (in green) at Yesler Terrace.

Activity stations contain fitness equipment such as Kompan's Complete Body Toner.

Activity stations contain fitness equipment such as Kompan's Complete Body Toner.

In addition to enhanced pedestrian amenities, larger trees and public art along the Loop, there are 8 "activity zones," each with at least one fitness station and a bench. The activity zones are equally distributed along the Loop, and the fitness equipment at each zone was selected to accommodate a range of ages and skill levels to make it easier for everyone to engage in healthy activity. From pull up bars to sit up benches to free runners, the activities provided offer a complete workout and encourage circulating around the neighborhood. 

The Loop was not only designed for physical health, but also to encourage a vibrant public realm that promotes economic development, increases safety by inviting more eyes on the street and breaks the cycle of social isolation that can beset recent immigrants and the elderly. Also arrayed around the Loop and throughout Yesler Terrace's streets are "pause places," which provide space to pull off the main path of travel to sit, lean, park a bike, wait for public transportation or catch one’s breath while navigating the steep terrain. Pause places are smaller than the activity zones, but are offered more frequently - approximately every 100 feet - on both sides of the street.

Creating a public realm that promotes physical activity will not only serve Yesler Terrace residents. Creating a socially and physically active streetscape could prove a powerful prescription for public health practitioners as our nation searches for ways to make preventative health care a daily part of our lives.

How to Make Your Own Native Plant, Bike Wheel Wreath

For our holiday card this year, we created a one of kind holiday wreathe using some of the tools of our trade: an old bike wheel and native plants harvested from our yards.  Even in the dead of winter, there are plenty of local, native plants that can be employed in our seasonal celebrations. So how did we do it? After securing an old bike wheel, we went looking for red-twig dogwoods (Cornus stolonifera) that had gotten a bit overgrown and harvested some of their branches, which stand out in the winter for their bright red color, and wove those through the spokes of the wheel until the rims disappeared. As accents, we arranged a few snowberries (Symphoricarpos albus) over cuttings of our native Oregon grape (Mahonia nervosa) and the ubiquitous sword fern (Polystichum munitum). And with that, a sustainable, recycled, locally-sourced holiday decoration.

For our holiday card this year, we created a one of kind holiday wreathe using some of the tools of our trade: an old bike wheel and native plants harvested from our yards.  Even in the dead of winter, there are plenty of local, native plants that can be employed in our seasonal celebrations. So how did we do it?

After securing an old bike wheel, we went looking for red-twig dogwoods (Cornus stolonifera) that had gotten a bit overgrown and harvested some of their branches, which stand out in the winter for their bright red color, and wove those through the spokes of the wheel until the rims disappeared.

As accents, we arranged a few snowberries (Symphoricarpos albus) over cuttings of our native Oregon grape (Mahonia nervosa) and the ubiquitous sword fern (Polystichum munitum).

And with that, a sustainable, recycled, locally-sourced holiday decoration.