(AP) - New Jersey's largest water company will increase its customer rates by 12 percent starting next month.

New Jersey American Water says the rate increases amount to about $6 more each month for water bills and about $4 for wastewater bills. It says the increase will help pay for an $868 million system overhaul.

The New Jersey Board of Public Utilities must still review the rate increases. If that panel approves a lower rate, New Jersey American Water says it will refund the excessive rates, with interest.

The rate hike follows a 6 percent drop in bills in April. New Jersey American Water attributed those drops to the federal tax overhaul.

New Jersey American Water serves more than 670,000 customers overall.