For the past 20 years, Northern Utility Services has been involved in the design, construction and operations of a wide variety of water and wastewater systems in the state of Alaska. As such, we have developed a highly skilled staff of water and wastewater professionals capable of competently servicing water and wastewater infrastructure.
For a full overview of our underground services please check our underground services page.
Underground utility locates are an important safeguard to protect your critical underground distribution system. In the State of Alaska, if an excavator damages an unmarked utility asset, he has no obligation to repair it. To ensure the underground assets of the utilities we serve are protected, Northern Utility Services service areas are registered with the Alaska Dig Line, and all locations are marked where excavations have potential to damage utility assets.
Water and sewer lines on private property as well as electric and gas utility extensions beyond the meter are owned by the property owner. As such, responsibility for any damage lies with the property owner. To ensure construction activity on private property does not damage underground utilities, Northern Utility Services provides private utility locates on an hourly basis. Requests for private utility locates can be made by the request a quote page.
Leak Detection makes business sense, and Northern Utility services provides state of the art leak detection services throughout the state of Alaska. Whether you simply need to find a service line leak, survey an entire distribution system, or obtain an emergency leak detection, our trained technicians are equipped to meet your needs.
Our leak detection efforts have saved our customers millions of dollars by eliminating systemic losses, expensive exploratory excavations, and by providing detailed reports to justify grants and low interest loans. Our successes have ranged from locating a tiny leak on a mile of 48 inch Steel main to locating a leak on HDPE Arctic Pipe. We have located hundreds of leaks in Anchorage, Wasilla, Kenai, and all over the state of Alaska.
Leak Detection Process
As part of our service, we provide an Initial consultation to learn system layout, leak symptoms and other information that may provide clues to narrow the search. Next, we utilize acoustic listening equipment to listen on valves and service lines to narrow down the search area. Finally, a leak noise correlator or tracer gas detector is used to pinpoint leak locations.
In the case of a system-wide leak survey, leak noise loggers are deployed throughout the system to record leak noise and develop a leak noise profile for the entire system. Leaks are then pinpointed and a comprehensive report is prepared to communicate the findings
Methods of Leak Detection
Acoustics Before using correlation (as described below), we use a high quality digital listening device to quickly survey the target area to identify the general location of the leak. In larger distribution networks, a series of correlating loggers will be deployed throughout the system to narrow the search area.
Correlation Leak Noise Correlation is a method for finding and pinpointing leaks in pressurized water pipes. A leak in a pipe under pressure creates noise that travels along the pipe, its contents, and through the surrounding ground.
How Leak Correlation Works
When two highly sensitive microphones are attached to a pipe with a leak, the sound from the leak takes longer to travel to the microphone furthest from the leak. By utilizing sophisticated software analysis tools and known sound travel speeds in different pipe sizes and materials, leaks can often be located within feet or even inches.
Hydrogen Tracer Gas Detection Due to its small and highly energetic molecules, hydrogen can be a useful tool for underground leak detection. A Hydrogen/Nitrogen gas mixture is introduced to the leaking section of pipe and allowed to migrate up through the soil where it can be detected with a sensitive hydrogen gas detector. Tracer gas leak detection can be an effective tool when searching for leaks on challenging pipe materials such as HDPE, PVC and Arctic Pipe and can even be effective in locating leaks under uncoated concrete slabs.
Possible Complications
Although underground leak detection employs finite scientific principals, many variables can cause inconsistent or inaccurate results. By eliminating these variables, leak detection efforts are more likely to provide accurate results. These variables are:
Pipe types, locations and depths. If location, or pipe routing is unknown, Northern Utility Services is equipped to locate underground piping. However some pipe materials can be difficult or impossible to locate using standard methods, and as a result, only a general leak location may be possible.
Ambient Noise. Although our equipment employs sophisticated noise filters, ambient noise can affect the results of leak noise correlations. To eliminate excessive noise, our leak noise loggers are capable of delaying the noise recording until the most quiet time of day or night.
System Usage. Water flow in the system causes noise of differing degrees, and can produce erroneous or confusing results. To minimize the effect of system usage, our leak noise loggers are capable of delaying the noise recording until a time of day when normal usage is minimal.
Radio Interference. Our primary leak correlation system uses radio signals to transmit the leak noise data from the two microphones to a centrally located receiver and processing software. If there is radio interference from something like a large radar tower, we may have to use other means which may be less accurate.
Tracer gas methods can be affected by impermeable soils such as clay and frozen ground, and accurate location of the targeted water line is critical to success.
Free Consulation
Each leak detection performed by Northern Utility Services begins with a free consultation where a leak specialist will learn about your particular circumstances and recommend the best technology. To request a free consultation, please use the “Request a Quote” button above, and a leak detection specialist will contact you right away.
Northern Utility Services provides fire hydrant maintenance, testing, and winterization services for over 100 fire hydrants throughout Anchorage and the Mat-Su Valley. Our crews are equipped with specialized tools and expertise to repair most common makes and models, and are equipped for fire flow testing and winterization.
Alaska’s freeze thaw cycle can damage fire hydrants rendering them non-functional. It is therefore critical to perform a full function test every year, and a monthly check during freezing weather to ensure the hydrant is functioning as required. Should a hydrant become damaged by frost action, our crews are fully equipped to complete repairs using minimally invasive methods.
Utility Locates
Call Before You Dig! Underground utility locates are an important safeguard to protect your critical underground distribution system. In the
Northern Utility Services provides fire hydrant maintenance, testing, and winterization services for over 100 fire hydrants throughout Anchorage and the
