NEW HANOVER COUNTY — Cape Fear Public Utility Authority (CFPUA) crews have stopped a wastewater spill that lasted more than 40 hours early Thursday morning.
Though the amount of untreated wastewater that reached nearby surface waters is still unknown, early testing results show fecal coliform levels have spiked in nearby waterways since the spill.
The overflow was caused by a 70s-era ductile iron pipe that spontaneously ruptured. Crews working nearby to replace Pump Station 10 first noticed the spill 8:30 a.m. Tuesday. The ruptured pipe was scheduled to be decommissioned in June 2020 around the same time the replaced pump station is estimated to reach construction completion.
To stop the spill, CFPUA crews installed a 500-foot temporary bypass that taps into a recently-constructed force main. During the 40-hour spill period, CFPUA continuously ran operated vacuum trucks near the spill to attempt to divert as much wastewater as possible from entering the stormwater system and nearby waterway.
Still, an unknown amount of wastewater reached Smith Creek. Test results provided by CFPUA show fecal coliform levels are, in some areas, drastically higher than usual. Samples that were taken around noon Tuesday (or about three hours after the spill was first noticed) show 100 milliliters of water at Smith Creek contained 86,640 fecal coliform organisms — CFPUA measures this by the ‘most probable number’ of viable bacteria cells per 100 ml of water, or MPN/ml) By Wednesday morning, the level of organisms jumped by a factor of 7, with 648,800 organisms measured.
Over approximately the same timeframe, concentrations at Burnt Mill Creek near Archie Blue Park increased by a factor of 97 (160 per 100 mL of water to 15,531); concentrations at the 23rd Street Bridge increased by a factor of 11 (161 per 100 mL of water to 15,531); concentrations at the Castle Hayne Road Bridge increased by a factor of 1,209 (20 per 100 mL of water to 24,196).