Installing a sewer line under wetlands and a busy highway
In May 2026, Brownline Canada contributed to the relocation of a sanitary sewer line in Mildred Lake, Alberta. The project involved two HDD crossings, one below inaccessible wetlands and the other below a busy highway. Thanks to the accuracy of the Drillguide GST, both crossings were drilled exactly as planned and with maximum efficiency.
Project background
Mildred Lake is an oil sands mining site. The mine is expanding after its previous source was depleted. As part of the expansion, some utilities are being relocated, including one of the facility’s sanitary sewer lines.
HDD contractor EnviroBore Directional Drilling Ltd. carried out two challenging trenchless crossings to install the new sewer lines. Brownline Canada was on site to survey the pilot drills using the Drillguide Gyro Steering Tool.
Accurate without requiring surface access
The two drills had similar lengths around 450 m (1500 ft). The first of the pair crossed under Highway 63, a major and busy highway. The second drill crossed under a wetlands area, where sand and clay layers are covered by peat. On both crossings, surface access above the drill line was very limited.
Because the Drillguide GST works independently of its surroundings, it is the ideal steering system for pilot bores in these conditions. The highly accurate gyroscopic measurements enable precise HDD crossings without surface access being a requirement.
Additional tracking for perfect punch-out
Near the exit point, where measuring from the surface was possible, additional tracking was done using Brownline’s GPS track. The compact surface unit makes it possible to perform secondary verifications on the measured drill head position. This combination of measurement techniques results in highly accurate punch-outs at the exit stake.
This was proven in this project, where both bores were carried out efficiently and punched out as planned and to the client’s satisfaction.
"Brownline's Drillguide GST proved to be a valuable addition on the Mildred Lake project, providing accurate guidance in conditions where conventional steering systems can be challenged. Combined with our experienced crews and proven HDD execution capabilities, this technology strengthens our ability to successfully complete complex crossings."
