A year after the city of Lawrence implemented curbside recycling, residents have grown accustomed to the convenience of setting out their bins of unsorted recyclable materials and having the city tote off their contents.

However, Sunday’s Journal-World story about the decline in the amount of glass the city actually is recycling is a disappointment to what seems like an otherwise successful curbside system.

There is some dispute about the actual numbers, but recycler Ripple Glass says it now receives 40 percent less glass from Lawrence than it did before curbside recycling began. Before Lawrence instituted curbside recycling, people who wanted to recycle glass had to take it to bins that contained only glass. Under that system, Ripple Glass was collecting about 100 tons of glass each month from Lawrence. Now it says it’s receiving about 60 tons per month.

The problem stems from the fact that glass mixed with other materials often picks up debris that contaminates the glass and makes it unsuitable for recycling. Whole bottles and jars and even clean broken glass are recyclable, but broken pieces of glass are difficult to separate from other recyclables. That makes it more difficult to recycle not only the glass but also the materials it is mixed with.

City commissioners were aware of the problems of including glass in the city’s curbside recycling program but wanted to make the system as easy as possible for residents. That’s understandable, but, a year into the program, that decision deserves review. Other cities have dealt with this problem in various ways. Perhaps the most convenient system would be to have local residents place glass in separate containers that would be picked up by trucks with separate compartments for glass. According to the city’s website, recycling bins for glass also remain available at a number of locations for residents who want to use that option.

Lawrence officials deserve credit for responding to the call for curbside recycling, but it appears that system may need to be refined. Most Lawrence residents probably would be willing to separate glass into a separate bin if they knew that would increase the amount of clean glass that could be successfully recycled. City officials should look at the costs and the options and see what they can come up with.