Alexandria, Virginia’s regional wastewater treatment provider, treating an average of 38 million gallons of wastewater per da ... y from over 300,000 customers in Alexandria and portions of Fairfax County, Virginia. Our office at 1800 Limerick St. is open 7:30 a.m. to 5 p.m. Mon-Fri. For assistance, call 703-721-3500. read more