To the visitor, the above-ground pipes running down many Edgewood streets give the appearance of a giant sprinkler system.

No, Providence Water Supply Board is not concerned by how green the neighborhood may be. Rather, they’re aware how brown the water has become.

“Water main replacement is our biggest priority right now,” says Providence Water spokesman David Nickerson. In an interview last week, Nickerson said more than 500 miles of cast iron pipe is reaching the end of its useful life of 75 to 100 years.

And, no, the above-ground system that runs along sidewalks and has earthen mounds allowing residents to access their driveways is not the replacement system. This is a temporary system ensuring customers service and working fire hydrants while six-inch cast iron pipes are removed and larger eight-inch ductile pipes (cement-lined iron pipes) are installed.

“A lot of them are 100 years old and there’s a lot of rust build-up,” said William Perry, site supervisor for Rosciti, the company Providence Water has contracted to do the Edgewood work. Rosciti is also replacing water mains in Providence and Pawtucket.

Perry estimated the Edgewood job would replace mains serving more than 200 customers. Among streets affected are Bluff, Berwick, Glen, Massasoit and Sefton.

Depending on variables such as encountering unmarked wiring and pipes – even trolley tracks on Narragansett Boulevard – from installation of the temporary system to the unearthing of the existing pipes and installation of the new can take five to six weeks.

Perry said each customer will get a new copper connection and that the Edgewood project will be largely completed by October. Before the new service is activated, the system and the water must be tested. Perry said “final restoration” would probably be done in December.

By then, Providence Water customers can also expect to learn of a hefty increase in water rates if approved by the Public Utilities Commission.

At a cost of $1 million a mile to replace water mains, Nickerson said the utility is faced with a half billion-dollar price tag. He said the utility would seek a 25 percent water rate increase. If approved, he said this would increase the monthly bill of the average residential customer by about $6. According to the Providence Water application filed with the Public Utilities Commission earlier this year, a residential customer using 74,800 gallons of water a year [the average] could expect to see their annual water bill go from $322.16 to $395.14. The rate application puts the overall increase at 24.3 percent and will collect an additional $14,619,888 in revenues.

Nickerson offered a bright side to this picture – Providence Water is better off than many other water supply companies because of an infrastructure replacement program initiated in the 1990s. That program set aside reserves to pay for upgrades and replacements to the infrastructure and treatment plant.

Also, augmenting the plan to replace water mains is a shift away from the lead service replacement program mandated by the state Department of Health. Nickerson said the system had 75,000 lead services. Because of concerns of lead entering customer supply, Providence Water signed a consent agreement with the Health Department to replace the service lines. Nickerson said tests have raised questions whether, in fact, replacing the service can introduce more lead into the system than leaving it undisturbed and the program has put on hold.

“We’re not so sure it’s a healthy thing,” he said of lead service replacements.

To date, about 25,000 lead services have been replaced.

Currently, Nickerson said, Providence Water is spending between $16 million and $18 million on upgrades and replacements. That would be increased by $6 million with approval of the rate increase.

Even with the added revenues, Nickerson said, “It’s going to take 20 years to get the bulk of the cast iron out [of the ground].”

According to the rate application filing, 73 miles of pipe would be replaced between 2014 and 2018 at a cost of $77 million, leaving a balance of 477 miles of cast iron pipes. Over a 20-year period extending to 2033, 343 miles of pipe would be replaced at a cost of $362 million.

In testimony filed with the PUC, Paul Gadoury of the Providence Water Supply Board said the unlined cast iron pipes “have become very problematical in terms of both water quality and delivery capacity. From a water quality standpoint, the interior rusted surfaces of these mains contribute to numerous instances of rusty, discolored water being delivered to customers.”

He goes on to testify that the internal rust of the pipes has reduced their diameter resulting in poor flow capacity and degradation of available fire flow protection.

Tom Kogut, spokesman for the PUC, said Tuesday hearings on the rate increase are slated to start Nov. 12.

As for Edgewood customers, the new pipes should ensure clear water and improved pressure. In the meantime, however, they’ll be putting up with a few bumps as they navigate over the temporary piping and a lot of digging.