MONTGOMERY COUNTY, Va. (WDBJ) – The New River Valley Water Authority has issued a boil water notice effective immediately for all customers throughout Montgomery County. The notice has been issued to customers of Blacksburg, Christiansburg, Virginia Tech and Montgomery County Public Service Authority Waterworks. The water authority says the boil water notice will remain in effect until safe drinking water test results occur from water sampling tests conducted by the Virginia Department of Health. All water samples collected will meet state and federal drinking water standards before the “boil water” notice will be lifted. It is unknown when the boil water notice will be lifted, but consumers are asked to plan on boiling water for at least 48 hours.