I'm writing about a position as a sanitation advisor. Which way is the correct way is right. Advisor or Adviser I'm so confused

Both spellings are correct.

Check these sites for more information.

http://www.agriculture.purdue.edu/agcomm/ontarget/0502/adviser_advisor.htm

http://www.wsu.edu/~brians/errors/adviser.html

http://www.thefreedictionary.com/advisor