Where the Grass is Greener

Jennifer Grzeskowiak

San diego and Des Moines, Iowa — at first glance, the two cities couldn't be more different. One is known for having near-ideal weather year-round, while the other averages more than 30 inches of snow per year.

Yet their yard waste programs bear a striking resemblance. Sure, Des Moines doesn't have to deal with educating residents about whether they can include palm fronds with their yard waste. But from deciding whether to automate to dealing with environmental issues that will affect the future of their operations, the programs have quite a bit in common. They prove that, regardless of geography and other factors, there's always something yard waste programs across the country can learn from one another.

Not an Automatic Decision

Currently, both cities are conducting pilot programs to determine the viability of automating their yard waste collection. And the decision hasn't proven easy for either of them.

While San Diego's recycling program is fully automated, in most areas of the city, yard waste is still collected manually. The exceptions are 12 routes in three neighborhoods that are part of the pilot program.

The first neighborhood joined the pilot more than five years ago, while the other two began participating within the last six months. In addition to finding the money to purchase new vehicles, contamination is one of the city's main concerns. “We have to strike a balance between efficiency and low contamination for a marketable [compost] product,” says Chuck Woolever, deputy director of the Environmental Services Department's Collection Services Division.

The automated trucks being used in the pilot are equipped with cameras, though Woolever says once the drivers can see any contamination, it's too late to prevent it from being mingled with the rest of the vehicle's load. Still, he notes that load checks on automated routes have revealed a less than 1 percent contamination rate.

And with the increased efficiency afforded by automation, Woolever foresees being able to add labor to clean the collected loads. The city also may test routes using semi-automated rear loaders with flippers that would allow workers to more easily audit every stop.

Des Moines has run into some of the same issues during the two years it has been running its automated pilot program. In the program, nearly 1,000 subscribers pay $125 per year for a yard waste bin. Bill Stowe, director of the Des Moines Public Works Department, says that residents often are reluctant to take on another bin.

Residents not in the pilot program purchase official program bags or stickers that can be placed on any approved bag. While Stowe says the city would like to automate the entire jurisdiction, such a move is going to take more consideration because of funding, among other factors.

Picking Up the Bill

Another similarity between both programs: Residents tend to think that collecting and composting yard waste somehow pays for itself. “There's a misconception that the program is making money,” says Amy Horst, a spokesperson for the Metro Waste Authority (MWA), which operates the composting facility to which Des Moines and 16 other area communities bring the yard waste they collect, and also provides collection bags for residents of the communities.

Horst says MWA has made keeping costs down for residents a priority. When MWA increased the price of a yard-waste bag from $1.50 to $1.55 in January, it was the first price hike in six years.

Horst adds that MWA subsidizes the cost of the program with tipping fees from Iowa's largest publicly owned landfill, which it also operates. And even though MWA pays haulers $82 per ton for the yard waste they bring to the facility, Stowe says Des Moines still loses about $100,000 per year in collection and other costs (although that makes up a relatively small portion of the department's more than $12 million annual budget).

Altogether, Des Moines collects about 7,500 tons of yard waste per year. In the most recent fiscal year, ended June 30, 2006, MWA processed 20,500 tons of yard waste, producing 16,000 cubic yards of compost. The collection and composting components of Des Moines' yard waste program are now operated separately.

The city used to run the facility where the composting now takes place until MWA consolidated the area recycling and composting programs in 2001. MWA took the various area programs, which had their own bags, rules and stickers, and standardized them under its Compost It! program.

Now, communities wanting to participate in the yard waste program approach MWA, which offers education and outreach services, such as flyers, newsletters and inserts for water bills. Of MWA's 17 member communities, 12 participate in the Compost It! program. Area residents who don't have access to the program still are able to drop their yard waste off at a designated MWA facility.

The programs run from April to November, although Des Moines will pick up yard waste any time of the year if residents put it out. In March, for instance, after a severe winter storm, Des Moines residents were able to put out cut and bundled debris marked with a Compost It! sticker at the curb for collection. The city made sure to educate residents about properly sizing the bundles they put out since workers can easily be injured during manual collection.

While MWA has tried to keep its yard waste programs' costs down, San Diego's city charter requires that residents not be charged for yard waste collection. In fact, it would take a two-thirds vote by the public to change that.

During the last few years, San Diego has seen the amount of yard waste it collects decline because of a drought in the area. The tonnage fell from 46,047 tons in fiscal year 2005 to 42,316 tons in FY 2006 and 38,182 tons in FY 2007.

With no signs of increased rainfall in the near future, Woolever expects collection this year to be in the 38,000-ton range again. When the rain does come, it's usually in the spring, prompting the busiest time of year for the program. San Diego collects yard waste year-round, but just like the rest of the country, Woolever says, “the trim line takes a big dip in the winter.”

With approximately 250,000 homes on its collection route, the program serves most of the city's residents. But, it hasn't always been that way. San Diego used to collect yard waste from only part of the city every week. To offer the service to more residents, the city began collecting every two weeks instead.

“That was the only way they could make it feasible,” says Jennifer Ott, outreach and education coordinator for San Diego's Environmental Services Department. “It was a difficult transition.”

To help residents remember their pickup date, the city sends them a refrigerator magnet calendar of their collection days, including holidays. Currently, the yard waste program is being promoted as part of the city's “Recycle or Else” program. Ott says there are two aspects of the “or else” ultimatum the city is trying to educate residents about: fines it will receive for falling below the state-mandated 50 percent recycling rate (San Diego met the 50 percent recycling requirement in 2004 and has maintained an estimated 52 percent rate) and the impending closure of the only city-owned landfill in 2012.

Breaking It Down

Like many other programs in the country, Des Moines and San Diego have been refining their composting operations over the years to offer a higher-quality product. For instance, San Diego's Miramar Greenery, located at the Miramar Landfill, used to only offer mulch, but now also produces a high-quality compost and ultra-fine materials for a variety of uses. Some of the yard waste also is used in the landfill for erosion control on slopes.

The waste that is processed comes almost exclusively from city routes. San Diego also takes some of the yard waste collected to other composting facilities to cut down on transportation costs.

The Miramar Greenery processes nearly 95,000 tons of yard waste per year using open windrows and an aerated Scarab windrow turner. The windrows are about eight feet high and 15 feet at the base. They used to be smaller, but the facility figured out that the increased size helped create a larger composting “sweet spot” and made better use of the available land.

To maintain the quality of the compost, Stephen Grealy, recycling program manager for the Environmental Services Department, says the facility is very strict about the material allowed into the facility. If a load is contaminated, the driver has to clean it, or the facility rejects the entire load. Not allowing residents to use bags anymore has helped, as well; residents now place their yard waste in bins.

Previously, the program allowed residents to use clear plastic bags that permitted drivers to more easily identify contaminants. But the bags would sometimes tear and pieces of them would end up in the load.

This posed a problem not only because of aesthetic issues with the final product, but also because the California Department of Transportation is one of the facility's main customers and can't have potential litter being used in highway projects. Grealy says the facility also was one of the first to purchase a Hurricane, which hooks onto the trommel screen and removes nails and plastic from the compost, further improving the quality of the finished product.

In Des Moines, MWA is working on further improving its product offerings by adding vacuum extraction devices that would suck out bags, the main contaminant. Its current equipment includes a Vermeer tub grinder, a Prospector 1-inch screen trommel, a Powerscreen 1/2-inch screen trommel and a CAT wheel loader. The Metro Compost Center has already modified its Scat windrow turner to add water to the piles as they're being turned to maintain the proper temperature.

After grinding, the material is placed in a trapezoidal pile that is up to 10 feet high and 100 feet long when fresh. After being turned once a month for six to nine months, depending on the weather, the piles reduce down to about five feet in height, Horst says.

MWA used to offer compost in 1-inch and 1/2-inch sizes, but now only offers the latter, which proved to be more popular, under the “Turf Gold Premium” label. The compost is sold to residents, governments and commercial users.

Planning Ahead

Aside from the typical challenges yard programs face, the two cities also are anticipating potential changes related to the nation's growing environmental concerns. Stowe, for instance, says that bio-renewal fuels are becoming more prevalent in the Midwest. As a result, there's a question about whether there could be a better beneficial reuse for wood debris, such as the production of ethanol.

In fact, an ethanol facility is going through the siting process in Des Moines, and Stowe says using wood chips to create ethanol is a possibility that should be considered. Some opponents of that proposition, however, have voiced concerns about how burning the materials affects air quality.

In general, Stowe says he would like to see some of the inconsistencies with laws regarding yard waste resolved. For instance, the regulation that bans yard waste from being landfilled throughout Iowa allows some metro areas to burn it. “There's a disconnect between intention and other allowances,” he says.

At Miramar Greenery in San Diego, area environmental concerns will likely lead the facility to cover its windrows with an AgBag or Gore cover within the next 12 to 18 months, Grealy says. The potential change stems from concerns about air quality contamination resulting from composting operations, he explains.

The South Coast Air Quality Management District (SCAQMD), which has jurisdiction over counties north of San Diego, has implemented rules requiring monitoring of emissions from composting operations and filtering of those emissions, including volatile organic compounds and ammonia. While not controlled by SCAQMD, Grealy says the facility wants to stay in step with area concerns.

Miramar Greenery is also considering the covers because it likely will be adding food waste from places like the Marine Corps Depot, Sea World, San Diego State University and PETCO Park to the compost. Since the facility is located next to the Marine Corps Station, preventing vectors and birds is crucial.

As San Diego and Des Moines illustrate, whether located on the sunny West Coast or in the snow-prone Midwest, cities across the country have recognized the contribution yard waste programs can make in reducing landfilled waste. Some of the details may be different, but remember that when looking for a solution to a yard waste conundrum, help is never more than a few collection routes away.

Jennifer Grzeskowiak is a contributing writer based in Laguna Beach, Calif.