PILOT MOUNTAIN — A consultant last week gave recommendations topping $1.5 million for water and sewer repairs, on top of the big water expansion project Pilot Mountain has in the works with the city of Mount Airy.
The Pilot Mountain Board of Commissioners held a special meeting Thursday night to hear from Ken Orie, director of engineering for utilities, with consulting firm WithersRavenel, which has worked with the town on a few projects in recent years.
The good news is that less than 5% of all water and sewer lines are in extreme danger of failing and on top of the priority list for replacement. The next highest category of high risk, however, did have a higher percentage of lines and much more estimated repair costs.
Orie said a few years ago the state created AIA grants (Asset Inventory and Assessment) which gives smaller communities the financial means to study their water and sewer utilities.
The grant are capped at $150,000, but Orie said Pilot Mountain was approved for a full grant on both the water and sewer services for a total of $300,000.
That allowed the town to hire WithersRavenel to develop an Asset Management Plan.
“On the sewer side we went out and inspected every single manhole … and every single lift station that you have as well as smoke-tested the entire town,” Orie said.
Town Manager Michael Boaz explained this test when the actions were taking place. A non-toxic smoke is forced into the main sewer lines (typically at a manhole) to see if any smoke escapes, indicating the presence of a leak.
According to one contractor’s website, finding leaks is necessary to avoid environmental and property damages that occur when the city’s sewage system is overwhelmed by storm water.
Orie said the test was done during the summer when the ground was dried out, so if any leaks were present, the smoke could filter up through the ground.
Looking at Pilot Mountain’s utilities, Orie said the town has 19 miles of sewer lines, ranging from a small 4-inch pipe to big lines of a foot and a half in diameter, with 424 manholes.
Another 4.5 miles are force mains in size of 1.5 inches to 8 inches.
These are the pipes that go out from the 20 lift stations and are under pressure, Orie explained.
In addition to having an updated map for all of the town’s sewer lines, Orie said of the inspection team, “We know the age, we know the material.”
Moving over to the water system, Orie said the town has 26 miles of water mains, ranging in size from 2 inches to 1 foot in diameter, with 380 water valves and 201 fire hydrants. The town has two water storage tanks.
The map is broader because the town has run water lines past the town limits to some locations but not sewer, he noted.
Like the sewer study, the team checked the age and material of the lines and hydrants, but Orie said they also did some “hydraulic modeling which allowed us to determine the fire flows in the entire system, how the pressure works.”
“This dramatically helps, especially considering with the new tie-in you’re going to have. We can help understand with the pressures that you’re getting on the new connection,” he said, referring to how Pilot Mountain is in the process of extending a water main to Holly Springs to connect with Mount Airy’s water service.
Considering the age and the material used in the sewer lines, WithersRavenel could come up with predictions on the risks of failure in different areas of town.
“Obviously, the older the pipe, the worse the condition of the manhole,” he said. “So it’s more likely that that pipe is going to need to be replaced in the very near future.”
Sewer mapping
Several sections of the town were shown in red for a “high” risk of failure on a colorized map shown to the group.
“The water side is more difficult because of the fact you can’t just open up a manhole and see the condition. So, you have to rely more on pipe material and pipe age. Water line fails at a more predictable rate the older it gets than necessarily sewer lines.”
On this map, most of the town was yellow for medium risk. Only a couple of small sections ventured into high or extreme risk.
When it comes to planning for repairs, logically it makes sense to budget for areas of extreme risk first, then high risk and then medium, Orie explained to the board.
Orie provided a chart that broke down the utility lines by risk category per linear foot.
The grand total at the bottom of the sewer chart showed $16.84 million.
“Obviously, this is a heart-attack moment,” Orie said upon revealing the chart. “Don’t get too focused on this because this is essentially if you replaced your entire system today. This is over the life cycle of a pipe, and the life cycle of a pipe is about 75 years.
“So when we’re talking about replacement of these low, medium and significant (pipes), we’re talking 20, 30 years out.”
Sewer lines only received a rating of extreme risk 4% of the time, or 4,285 linear feet.
Using a figure of $155 per foot to replace the line, that would come to $664,200 for extreme risks. Using a slightly higher weighted cost of $159, the total would be $681,400.
This would be the area to prioritize for replacement.
Unfortunately, WithersRavenel considered four times as much sewer line to be in the high-risk category, about 16,557 feet. At the same two costs ($155 or $159), the total to replace would be $2,566,000 or $2,633,000.
There are things local government can do to extend the usefulness of its utilities.
“Yes, these high and extremes areas need some attention in the next five years.”
“It’s kind of like the ‘check engine’ light comes on in your car. You don’t necessarily know it’s your gas cap until you’ve taken it in and looked at it.”
Gesturing to the high and extreme rows on the chart, he said, “These could just be the gas cap, or it could be your engine dripping oil and you’re lucky to make it out of the gas station.”
Water mapping
The water impact chart had an even bigger bottom line of almost $30 million.
Less than 5% of the water lines are a dangerous threat.
The estimated cost for repairs had a much greater spread as Orie showed $142 and $253 per foot, with a weighted figure of $198 leading to the total of $29.97 million.
Only a third of 1% (501 feet) is considered an extreme risk needing immediate addressing, with a weighted cost of $99,100.
High risk was listed at 4%, 5,742 feet, for a total of $1,137,000.
In looking at a long-range plan, WithersRavenel suggests that all of the extreme-risk sewer lines be replaced at that estimated $681,400. The consultants also suggest work on pump station 18 and a crossing at $552,000, for a total of $1.23 million.
Orie advised the board, “This report is a draft. … We’re going to work with the town, go over these recommendations, go over these ideas and thoughts, and see where they need to be tweaked.”
“When we finalize the projects, the time table, then we’re going to complete the rate study that says, ‘This is the impact that these projects would have.’ And then those (rate suggestions) will be presented to you.”
He can also work with the town on funding strategies, looking for outside grants and monies to assist in the work.
He also suggested the town consider examining the inside of the sewer lines in select areas from time to time with a closed-circuit TV camera. In some cases, a pipe might be strong enough to just put a liner inside — with a significant cost savings to the project.
“You would go from $143 a linear foot to $25 a linear foot,” he said.
At the end of the presentation, Commissioner Dwight Atkins asked if a copy of the report would be going to the N.C. Department of Environmental Quality and if this would benefit the town by showing its need as a “distressed unit.”
Town Manager Michael Boaz said the DEQ paid for the study through the grants, so obviously it will want a copy of the results.
“It goes toward ‘points’ on the next application,” added Orie, referring to seeking money from the N.C. State Revolving Fund for water and sewer needs. “Now that you have an AMP, should you apply for SRF funds, you get additional points and additional credits — not so much on the distressed aspect, but for having your stuff together … and working proactively instead of reactively.”
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