North Holland
No Digging, Just Drilling
Water Pipeline in the Bulb Region
Getting a water pipeline into the ground amidst the flower bulb fields in the northern part of North Holland is quite a challenge. The bulb fields must not be accessed, and saline groundwater must absolutely not reach the surface. Nevertheless, the job was completed on schedule. This was thanks to the entire team, including our own drilling specialists.
Those who have never seen the flower bulb fields in person might know them from the calendars sold, for example, at Schiphol Airport. Not only are they a beautiful sight, but the bulbs are also an important export product, and as a country, we do everything to protect them.
Harmful Saline Groundwater
The subsoil in this region contains saline water that can rise to the surface when certain soil layers are excavated. Laying a new pipeline in such an area is therefore not easy. Nevertheless, water company PWN wanted to adapt the water pipeline because the demand for drinking water in the northern part of North Holland had increased. The 400 mm diameter pipeline therefore had to be replaced by a 600 mm pipeline. A.Hak was awarded the contract to replace the pipeline over a total length of 5.9 km.
Drilling as a Puzzle Piece
PWN set two important conditions: the pipeline had to be made of steel, and the bulb fields were absolutely not to be entered. That presented quite a challenge for the team. “We started construction last October, but we were already drawing up plans in January,” says project leader Peter Hesselink.
Based on the years of experience of our own drilling specialists, it was immediately clear that horizontal drilling would form an important part of the puzzle’s solution. “If a trench cannot be dug, you drill,” says Peter. “For us, that’s logical, but for the local community, it remains spectacular. That proved to be the case again. The drilling under the village of Westwoud, at a maximum depth of about 25 meters, was featured in the Noordhollands Dagblad newspaper.”
Engage with the Local Community
The fact that we have a lot of experience with guided drilling does not mean it’s easy. Integrating the drillings into the route and designing the individual drillings within the possibilities and limitations of the soil conditions are just a few examples of the various puzzle pieces. “Coordination with the local community was also very important in this project,” says Peter. “Devising a plan is one thing; drawing a line on paper is easy. But practice always turns out differently. Half a day’s work can easily turn into a full day if you suddenly encounter a fence along the way that wasn’t in the plans.”
Proud of the Accomplishment
The water issue also required a significant amount of preliminary research. Peter: “We spoke with quite a few parties to get the best possible picture of the water management and the effects of dewatering. We wanted to be absolutely sure that it would go well, and it did.” Peter is proud that they can complete the job with a relatively small team. “We are only about fifteen to twenty people. With that, we are laying the pipeline nicely within budget and on schedule. That is an achievement!”
