Beset with delays, rising costs and regulatory scrutiny, Honolulu’s light rail project faces another challenge—bird excrement. According to a safety hazard analysis from the Honolulu Authority for Rapid Transportation, birds nesting inside the rail line’s hollow guideway over the last several years have left substantial amounts of guano in multiple locations, putting workers’ health at risk. Bird and rodent control issues were identified before construction got underway, but no funds were allocated. HART estimates that remediation will cost nearly $1.4 million.