SUN CITY - All over the Valley and Arizona, water lines are growing old -- and not very gracefully.

Engineers say they outlive their use after 50 years, and we're all going to have to pay to retire and replace them.

EPCOR is getting ahead of the aging cycle in Sun City.

"The issue here in Sun City is just the age of the infrastructure," said Shawn Bradford, a top executive with EPCOR, the largest private water company in the state and a leading water provider in the West Valley

The company's workers were putting the finishing touches Monday on a manhole for a new wastewater line to a subdivision near W. Olive and N. 111th avenues.

The 49-year-old cement lines were replaced with brand new PVC lines that Bradford says will last just as long.

"When we took it out, it actually fell apart," Bradford said of the corroded old line. "That tells us we were right here where we needed to be, making the investment at the right time."

The cost to replace the old water lines is about $1 million a mile, Bradford said. Sun City's 300 miles of water lines includes 70 miles that are at least 50 years old, he said.

EPCOR's Sun City customers have been paying for the upgrades. Water rates climbed about 20 percent from 2011 to 2015, to almost $42 a month.

The company expects to seek approval in April from the Arizona Corporation Commission for new upgrades. A planned creation of an EPCOR wastewater district across several municipalities would spread the costs. Any rate changes would vary, Bradford said.

"It's just like a car -- it's not going to maintain itself forever," said Mike Worlton, a civil engineer with GHD who chaired a committee that gave Arizona a C-minus last year for its drinking-water systems. "The reason we got dinged is because we need to have the financing in place to do the work, we have to have the planning."

If you're worried about the water lines in your neighborhood, Worlton says you should ask your local elected official these questions:

-How old are the lines in my neighborhood?

-Have you analyzed where the weaknesses are?

-What's the plan to upgrade them?

-How will we pay for it?