The pH of Black Creek in its upper reaches ranges from 6.1 to 6.4. At the Hazleton High School it ranges from 4.9 to 6 and at the Hazleton Wastewater Treatment Plant from 5.5 to 6. Downstream of the plant the pH ranges between 6.4 and 7. At the bridge at Tomhicken it ranges from 6.1 to 6.7 and at the State Route 3020 bridge from 6.2 to 6.8. Above and below the Gowen Discharge, the creek's pH ranges from 6.3 to 6.8 and 4.6 and 6.2 respectively. Upstream of the State Route 3018 bridge, the pH ranges from 4.6 to 6.3 and near the mouth between 4.6 and 6.8.