The time has finally come to say goodbye to a trusted workhorse. James Page, park maintenance manager with the Dallas Park Maintenance Services Division, is parting ways with his aging fleet of diesel mowers.

“We can still mow with them, but that’s an aged diesel engine, before any environmental restrictions were put on turf equipment,” Page explains. “Now we’re looking to phase them out of the fleet.”

Cleaner, Greener Fleets

Dallas is just one of a number of U.S. cities that are gradually replacing their fleets of diesel mowing equipment with alternative fuel versions. Many are motivated by city-wide environmental sustainability policies calling for greener fleets and reduced carbon footprints. 

“One of our interview questions for new employees is ‘What impact does grounds maintenance have on the environment?’” Page says. “The answer is basically everything.

“The new mowers have been a great tool for reducing the environmental footprint of our parks,” Page continues. “Along with a proactive wildflower program we started almost six years ago now, which involves planting new areas of wildflowers in our parks every year to reduce mowing. Our improvements with propane and wildflowers have reduced mow time, improved emissions and improved the curb appeal of park lands. Definitely a win-win for the environment and park users alike.”

The decision in Dallas to purchase the propane mowers was made easier by rebate programs, such as the U.S. Department of Energy’s Clean Cities program, which is designed to reduce petroleum use in transportation, and the Texas Environmental Rebate Program, which helps replace outdated agricultural tractors.

“We’re constantly researching cleaner-burning equipment that will meet our needs, and we keep our eyes out for rebate programs,” Page says. 

In Columbus, Ohio, the goal for the city to become more green comes from Mayor Michael B. Coleman.

“The mayor has really made a very concerted effort to become more green throughout the entire city,” says Terri Leist, assistant director of the Columbus Recreation and Parks Department. “We’re encouraging recycling for residents, planting more trees in the city’s right-of-ways, and moving toward propane equipment and vehicles, which is how we came upon the use of propane mowers.”

The department purchased 12 zero-turn propane mowers and put them to use in April 2013. According to Park Maintenance Manager David Stearns, the mowers are deployed in seven of the department’s 12 zones and are primarily used for mowing parkland.

“We’re running a combination of gasoline and diesel mowers in addition to propane,” Stearns says. “In the long term, we want to switch to propane where possible.”

Mow in the Know

Both Dallas and Columbus implemented extensive staff training for the switchover. One important aspect of both training programs is that they include training even for employees who may not be operating the mowers initially. 

“We have a diversely trained work unit, so if the equipment operator is absent, then we do have some backups who know preventative maintenance and safe operation of that mower,” Page says.

Fuel Efficiency

Although Page estimates that fuel costs for propane mowers are 30 to 50 percent less than diesel, it’s another form of efficiency that really caught his attention.

“Right away we saw an improvement in efficiency in locations that were not equipped with fuel pumps by not having to refuel daily,” Page says. “We have a large propane storage cage, and the propane company delivers twice a week, so we have fresh propane onsite and always ready.”

Many of the department’s mowers are dual-fuel models that run on either propane or unleaded gasoline. On ozone action days in Dallas, unleaded fuel has to be limited before 10 a.m., but the mowing crews can still get an early start by using propane instead. Most of the time, operators stick with using propane all day, but the unleaded gas tank serves as a backup.

“We really gained an efficiency with fueling, because by the time you have two propane tanks and a gas tank, it limits refueling to about once a week per mower,” Page explains.

Using propane also eliminates the possibility of fuel spills, which can be expensive and time consuming to clean up.

“Cost, longevity, spilling, safety — all factors that were a concern,” Page says. “I think as far any equipment operations, you must match the mower to the application.”

The Long Run

Naturally, newer mowers are going to have less downtime than older models, no matter what they run on. But Page and Stearns are optimistic about the potential longevity of propane mowers.

“We put the mowers through a good two to three pilot programs to test wear and tear, terrain, engine, stability, performance and replacement parts, and basically what we found is that the propane vs. diesel unit stood up to be the same,” Page recalls. 

“Our mechanics feel that since they burn cleaner and the engines and oil don’t get as dirty, they will have a lot longer lifespan and a lot fewer maintenance issues,” Stearns says. “If true, I believe in the long run these mowers will be great for us….Employees have commented that they are way quieter, cut well and have very little fumes. It’s been working very well.”

Elizabeth Beard is the Managing Editor of Parks & Recreation.