DELPHOS — The city of Delphos got a significant boost in its efforts to improve its wastewater treatment system. On Thursday, the city was issued an $4.57-million, interest-free loan from the Ohio Environmental Protection Agency’s Water Pollution Control Loan Fund. The 30-year loan will both reimburse funds for a pilot project conducted at the treatment plant last year as well as fund the replacement of two existing influent screens with mechanical screens as well as the addition of a second train of membrane biological filtration. “It’s a very important piece of what we’re trying to do,” Delphos Safety Service Director Shane Coleman said.