As the costs of operating its municipal sewer system rise, a city in Saitama Prefecture is hoping to cash in on the growing popularity of manhole cover designs with a plan to use the creative lids as an advertising medium.

The Tokorozawa Municipal Government will start accepting applications from companies and small businesses Thursday, and the first cover with an advertisement is expected to debut in October, as the city looks to tap into the new revenue source. According to the city, the project is the first of its kind for a municipality in Japan.

A total of 38 covers situated on busy streets around train stations will be available as ad space. Those who want to put their ads on manhole lids must submit a design to the city and pay ¥40,000 to have the cover created. The monthly advertisement fee will be ¥7,500. If the project is a success, more lids could be used as advertising space in the future. "We hope the project will improve the image of the sewer system. We also hope this will be a source of revenue in addition to sewage service charges (collected from residents) to cover operational costs," a city official told The Japan Times on Tuesday.