PILOT MOUNTAIN – A consultant last week gave recommendations in excess of $ 1.5 million for water and sewage repairs, in addition to the major water expansion project that Pilot Mountain has in the works with the city of Mount Airy.
The Pilot Mountain Commissioner Council held a special meeting on Thursday night to hear Ken Orie, director of public service engineering at the consulting firm WithersRavenel, who has worked with the city on some projects in recent years.
The good news is that less than 5% of all water and sewer lines are at extreme risk of failure and top of the priority list for replacement. The next high-risk category, however, had a higher percentage of lines and much more estimated repair costs.
Orie said that a few years ago the state created subsidies from the AIA (Inventory and Asset Assessment) that provide smaller communities with the financial means to study their water and sewage services.
The grant is limited to $ 150,000, but Orie said Pilot Mountain has been approved for a total grant for water and sewage services for a total of $ 300,000.
This allowed the city to hire WithersRavenel to develop an Asset Management Plan.
“On the sewer side, we go out and inspect every manhole … and every pumping station you have, as well as smoke testing across the city,” said Orie.
The city manager, Michael Boaz, explained this test when the actions were taking place. Non-toxic smoke is forced into the main sewer lines (usually in a manhole) to see if any smoke escapes, indicating the presence of a leak.
According to a contractor’s website, finding leaks is necessary to avoid environmental and material damage that occurs when the city’s sewage system is flooded with rainwater.
Orie said the test was done during the summer, when the soil was dry, so if there was a leak, the smoke could filter through the soil.
Looking at Pilot Mountain’s utilities, Orie said the city has 19 miles of sewer lines, ranging from a small 4-inch pipe to large one-and-a-half-diameter lines with 424 manholes.
Another 4.5 miles are power networks with sizes from 1.5 inches to 8 inches.
These are the tubes that come out of the 20 pumping stations and are under pressure, explained Orie.
In addition to having an updated map of all the city’s sewer lines, Orie said of the inspection team: “We know the age, we know the material”.
Switching to the water system, Orie said the city has 26 miles of water mains, ranging in size from 2 inches to 1 foot in diameter, with 380 water valves and 201 hydrants. The village has two water storage tanks.
The map is broader because the city has passed water beyond city limits to some locations, but not sewage, he noted.
As in the study of sewage, the team verified the age and material of the lines and hydrants, but Orie said that they also did “hydraulic modeling that allowed us to determine the flow of fire throughout the system, how the pressure works”.
“It helps a lot, especially considering the new combination you will have. We can help you understand the pressures you are receiving on the new connection, ”he said, referring to how Pilot Mountain is in the process of extending a water pipe to Holly Springs to connect with Mount Airy’s water service.
Considering the age and material used in the sewer lines, WithersRavenel can make predictions about the risk of failure in different areas of the city.
“Obviously, the older the pipe, the worse the condition of the well,” he said. “Therefore, it is more likely that this tube will need to be replaced in the very near future.”
Sewage mapping
Several sections of the city were shown in red for a “high” risk of failure on a colored map shown to the group.
“The water side is more difficult because you can’t just open a manhole and see how it is. Therefore, you have to rely more on the material and the age of the tube. The waterline fails at a more predictable rate the older the sewer lines necessarily get. “
On this map, most of the city was yellow for medium risk. Only a few small sections have ventured into high or extreme risk.
When it comes to repair planning, it makes sense to budget for extreme risk areas first, then high risk and then medium risk, Orie explained to the board.
Orie provided a graph that detailed the utility lines by risk category per linear meter.
The grand total at the bottom of the sewage chart showed $ 16.84 million.
“Obviously, this is a time of heart attack,” said Orie as he revealed the chart. “Don’t be too focused on that because that is essentially if you replaced your entire system today. This ends in the life cycle of a tube, and the life cycle of a tube is about 75 years.
“So, when we are talking about replacing these low, medium and significant (tubes), we are talking about 20, 30 years.”
Sewer lines received only an extreme risk rating 4% of the time, or 4,285 linear feet.
Using a value of $ 155 per foot to replace the line, that would be $ 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 in the high-risk category, about 16,557 feet. With the same two costs ($ 155 or $ 159), the total to be replaced would be $ 2,566,000 or $ 2,633,000.
There are things that the local government can do to extend the usefulness of its public services.
“Yes, these high and extreme areas need some attention in the next five years.”
“It’s as if the ‘check the engine’ light comes on in your car. You don’t necessarily know what your fuel limit is until you pick it up and look at it. “
Gesturing to the high and extreme lines of the graph, he said: “This could just be the fuel tank cap or it could be your engine oil dripping and you are lucky to be able to get out of the gas station.”
Water mapping
The water impact graph had an even greater bottom line, at almost $ 30 million.
Less than 5% of water lines are a dangerous threat.
The estimated cost of repairs was much more widely distributed, as Orie presented $ 142 and $ 253 per foot, with a weighted value of $ 198 leading to a total of $ 29.97 million.
Only a third of 1% (501 feet) is considered an extreme risk that needs immediate treatment, with a weighted cost of $ 99,100.
The high risk was listed at 4%, 5,742 feet, for a total of $ 1,137,000.
When looking at a long-term plan, WithersRavenel suggests that all extreme risk sewer lines be replaced by about $ 681,400. Consultants also suggest works on pumping station 18 and a crossing of $ 552,000, for a total of $ 1.23 million.
Orie advised the council: “This report is a draft. … We will work with the city, review these recommendations, review these ideas and thoughts and see where they need to be adjusted ”.
“When we finish the projects, the schedule, we will complete the fee study that says, ‘This is the impact that these projects would have.’ And then these (rate suggestions) will be presented to you. “
He can also work with the city on financing strategies, looking for grants and outside money to help with the job.
He also suggested that the city examine the interior of sewer lines in selected areas from time to time with a closed-circuit TV camera. In some cases, a tube can be strong enough to just put a liner inside – with significant cost savings for the project.
“You would 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 the North Carolina Department of Environmental Quality and whether it would benefit the city in showing its need as a “struggling unit”.
City manager Michael Boaz said DEQ paid for the study through grants, so he obviously wants a copy of the results.
“Go to ‘points’ in the next application,” added Orie, referring to the NC State Revolving Fund’s money search for water and sewage needs. “Now that you have an AMP, if you sign up for SRF funds, you earn additional points and credits – not so much in the distressed aspect, but for having it all together … and working proactively rather than reactively.”