Pilot learns of water, sewer trouble spots

PILOT MOUNTAIN – A consultant last week made recommendations exceeding $ 1.5 million for water and sewer repairs, in addition to the major water expansion project that Pilot Mountain is doing in partnership with the City of Mount Airy.

The Pilot Mountain Board of Commissioners held a special Thursday evening to hear from Ken Orie, Director of Engineering for Utilities, with consulting firm WithersRavenel, which has worked with the city on a number of projects over the past few years.

The good news is that less than 5% of all water and sewer lines are at extreme risk of failure and are high on the priority list when it comes to replacement. However, the next higher high risk category had a higher percentage of lines and much more estimated repair costs.

Orie said a few years ago the state created Asset Inventory and Assessment (AIA) grants that give smaller communities the funding to research their water and sanitation utilities.

The grant is capped at $ 150,000, but Orie said Pilot Mountain has been cleared for a full grant for both the water and sewer systems for a total of $ 300,000.

This enabled the city of Withers to hire Ravenel to develop an asset management plan.

“On the sewer side, we went out and inspected every single manhole … and every lift station you have and tested the entire city for smoke,” Orie said.

City administrator Michael Boaz explained this test when the actions took place. A non-toxic smoke is pushed down the main sewer lines (usually at a manhole) to see if there is smoke, which indicates the presence of a leak.

According to a contractor’s website, finding leaks is necessary to avoid the environmental and property damage that occurs when the city’s sewer system is overwhelmed by rainwater.

Orie said the test was done over the summer when the soil dried out. So if there were leaks, the smoke could filter through the floor.

Looking at Pilot Mountain’s utilities, Orie said the city has 30 km of sewer lines ranging from a small 4-inch pipe to large one and a half feet in diameter and 424 manholes.

Another 4.5 miles is 1.5 “to 8” power lines.

These are the pipes that come out from the 20 lift stations and are under pressure, Orie explained.

Not only did Orie have an updated map of all the city’s sewers, but he said of the inspection team, “We know the age, we know the material.”

Orie switched to the water system and said the city had 26 miles of water pipes ranging in size from 2 inches to 1 foot in diameter, with 380 water valves and 201 hydrants. The city has two water storage tanks.

The map is wider because the city had aqueducts to some places beyond the city limits, but no sewers, he noted.

As with the sewer study, the team checked the age and material of the pipes and hydrants, but Orie said they also created some “hydraulic models that allowed us to determine the fire flows throughout the system, how the pressure works”.

“This helps dramatically, especially given the new connectivity you will have. We can help you understand the pressure you are putting on the new connection, ”he said, referring to how Pilot Mountain is about to extend a water line to Holly Springs to connect to the Mount Airy water service.

Given the age and the material used in the sewers, WithersRavenel could make predictions about the risk of failure in different parts of the city.

“The older the pipe, of course, the worse the condition of the manhole,” he said. “So it’s more likely that this tube will need to be replaced in the near future.”

Canal mapping

Several parts of the city were shown in red on a colored map that was shown to the group in order to ensure a “high” risk of failure.

“The waterside is more difficult because you can’t just open a manhole and see the condition. So you have to rely more on the pipe material and pipe age. The aqueduct is failing at a more predictable rate the older it gets than necessarily the sewer. “

On this map, most of the city was yellow for medium risk. Only a few small sections dared to take a high or extreme risk.

When it comes to planning repairs, it logically makes sense to budget for areas of extreme risk first, then high risk, and then medium risk, Orie told the board.

Orie provided a chart showing the supply lines broken down by risk category per linear foot.

The grand total at the bottom of the sewer was $ 16.84 million.

“Obviously this is a heart attack,” Orie said as he revealed the card. “Don’t focus too much on it because that’s essentially what happens when you’ve replaced your entire system today. This is about the life cycle of a pipe and the life cycle of a pipe is around 75 years.

“So when we talk about replacing those low, medium, and significant (pipes), we are talking about 20, 30 years.”

Sewers received an extreme risk rating, or 4,285 linear feet, only 4% of the time.

Using an amount of $ 155 per foot to replace the line, it would be $ 664,200 for extreme risks. At a slightly higher weighted price of $ 159, the grand total would be $ 681,400.

This would be the area that needs to be prioritized for sharing.

Unfortunately, WithersRavenel considered four times as many sewers as a high risk category, about 16,557 feet. For the same two costs ($ 155 or $ 159), the amount to be replaced would be $ 2,566,000 or $ 2,633,000.

There are things the local government can do to add value to their utilities.

“Yes, these high and extreme areas need some attention over the next five years.”

“It’s like the engine indicator light comes on in your car. You don’t necessarily know it’s your gas cap until you’ve picked it up and looked at it. “

Pointing to the high and extreme rows on the map, he said, “This could just be the fuel cap, or it could be your engine dripping oil and you’re lucky enough to get out of the gas station.”

Water mapping

The water impact graph had an even bigger profit of nearly $ 30 million.

Less than 5% of water pipes are a dangerous threat.

The estimated cost of repairs was much greater as Orie was $ 142 and $ 253 per foot, with a weighted number of $ 198 making it $ 29.97 million in total.

Only a third of 1% (501 feet) is considered an extreme risk that needs to be addressed immediately, with a weighted cost of $ 99,100.

The high risk was cited as 4% (5,742 feet) for a total of $ 1,137,000.

When considering a long-term plan, WithersRavenel suggests replacing any extreme risk sewer lines at this estimated price of $ 681,400. The consultants also suggest work on pumping station 18 and a $ 552,000 crossing for a total of $ 1.23 million.

Orie advised the board: “This report is a draft. … We’re going to work with the city, go through these recommendations, go through these ideas and thoughts and see where they need to be tweaked. “

“When we finalize the projects and the schedule, we will complete the rate study which says, ‘This is the impact these projects would have. ‘And then these (price proposals) are presented to you. “

He can also work with the city on funding strategies and seek outside grants and funds to help with the job.

He also suggested that the city inspect the interior of the sewer pipes in selected areas with a surveillance camera from time to time. In some cases, a pipe can be strong enough to put just a liner in it – with significant cost savings for the project.

“You’d go from $ 143 per linear foot to $ 25 per linear foot,” he said.

At the end of the presentation, Commissioner Dwight Atkins asked if a copy of the report would go to NC’s Environmental Quality Department and if this would benefit the city by showing its need as a ‘unit in need’.

City administrator Michael Boaz said the DEQ paid for the study through the grants, so it will obviously want a copy of the results.

“The next application is for ‘points,'” Orie added, referring to finding money from the NC State Revolving Fund for water and sanitation needs. “Now that you have an AMP, you will earn extra points and credits when you apply for SRF funding – not so much for the desperate aspect, but for having your things together … and being proactive rather than reactive work.”

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