The average aide salary at Waterville was $17,647 , which is 47 percent lower than the average salary for this job in Washington, and 45 percent lower than the national average for this job . Aide salaries at Waterville typically range from $14,285 to $22,110 (25th to 75th percentile). The highest reported aide salary was $22,774. There are 7 employees at Waterville with the job title aide.