Running 17 days with 364 shows and exhibits, the Three Rivers Arts Festival is the largest free public event nationwide -- and now, it is the most environmentally friendly, too.

That's according to Ryan Walsh, founder of Restorative Events, which was formed in 2007 to research the best practices at events elsewhere to help Pittsburgh to do the same here. But the locally based organization quickly discovered concerts and other events that were marketing themselves as eco-friendly actually weren't, so it shifted its focus to making them so.

The arts festival was the first large-scale event that Restoration Events has coordinated with a goal of making it green. It diverted as much of the event's trash into a recycling or composting stream as possible and hopes its experience at the festival can be used to help establish a national standard for green events much as developers use Leadership in Energy and Environmental Design standards to rate buildings on their level of environmentally sustainable construction practices.

Appropriate modifications will be made to accommodate the needs of events, but the certification process will have the same LEED structure as buildings do, Mr. Walsh said. "The larger-scale vision is to be a leader in creating a national green event standard that will be accepted by the U.S. government and will be used nationwide," he said.

As a result of the systematic changes, such as the distribution of eco-friendly products to food vendors that could be either recycled or composted once customers were finished eating, only 16.4 percent of the festival's waste was sent to landfills, compared with 85 percent last year, Mr. Walsh said.

Among the compostable products, which are capable of breaking down into soil and mulch over several months, were starch drinking cups. Although they looked like plastic, the cups were made from corn rather than petroleum and can be composted to make mulch.

"Next arts festival, we'll have mulch, not a cup [in a landfill]," Mr. Walsh said. "Everything at the arts festival that you receive in your hand is either recyclable or compostable."

Other compostable products used were potato-starch eating utensils and wood-pulp plates.

To ensure these products were put into the recycling or composting stream, Mr. Walsh instituted a two-fold education program: Signs were placed throughout the festival informing consumers on how to dispose of their trash, and "educators" were hired to stand at each trash area to make sure the trash was properly placed, as well as to teach consumers how to be more environmentally aware in their own homes.

"You can provide all the products you want at an event that are going to be environmentally friendly, but if the person who receives them doesn't know what to do with it, that's not going to work towards the overall goal," Mr. Walsh said.

At the same time, Restorative Events was careful not to force opinions on festival-goers. Along with each recycling and composting bin, for example, there also was a regular trash receptacle for those who chose not to participate in the festival's eco-friendly goals.

"Our intention is to give people all of the information that they need to make a choice and then to document what their choice is," Mr. Walsh said.