DES MOINES — Iowa senators voted 30-18 on Tuesday to approve legislation directing the state Department of Human Services to upgrade its system of verifying eligibility for public assistance programs.Senate File 389, which passed on a party-line vote, proposes the state agency buy the system or enlist a private vendor to verify assets, identity and other eligibility requirements for hundreds of thousands of Iowans participating public assistance programs involving federal and state benefits no later than July 1, 2022.“I’ve worked this around and I believe it a pretty solid finished product,” said Sen.