"There's probably going to still be an odor . . . and the chemical likes metal and glass, so be sure those areas are clean," Hayes told Nitro school officials. "You may see a film. That's a visual sign that things may not be as clean as they need to be."
Hayes' job is to make sure the protocol is being strictly followed, but there are some questions he can't answer -- such as concerns about the chemical from two pregnant teachers at the school.
"We want to make sure everyone's following the same procedure," Hayes said. "The intent is just to purge the [water] lines of any potential contaminants. After two to three cycles, then you can return to using water normally."
Dianne Smith, principal at Nitro High, said there's another concern for the area's teachers outside of student safety: the impact the days off will have on student achievement.
Kanawha County students returned from a nine-day holiday break on Jan. 3, only to face more days off because of subzero temperatures.
In the past two weeks, students have attended school for just four days, and one of those featured a two-hour weather delay. On Monday, the students are off for Martin Luther King Jr. Day.
"A very big concern is instruction. Our plan is to move on and cover curriculum as optimally as possible. It's an unprecedented event and everyone is trying to cope and make sure our kids remain safe," Smith said. "I'm sure the central office will advise us on what to do. All we can do now is weather this storm and wait."
Kanawha County Schools Superintendent Ron Duerring said Wednesday that even though some schools have already been approved to open, the district would "more than likely not" re-open until all schools are ready to go.
"This is taking longer than we thought it was going to," Duerring said.
Flinn Elementary School in Sissonville was at a standstill Wednesday -- the health department had come and gone, waiting for plumbers to make their rounds.
Nancy Hamilton, a clerk at the school, said the staff hasn't decided yet how to address the issue with its students, but her granddaughter, who is in the fourth grade, is already asking questions.
"They [the students] are watching all of this," Hamilton said. "They know what's going on."
Staff writer Rachel Molenda contributed to this report.
Reach Mackenzie Mays at mackenzie.m...@wvgazette.com or 304-348-4814.