Twenty years ago, the focus was more on water management than on water treatment. The challenges revolved around how water could be pumped away, rather than how it could be treated. In the past, construction projects were never halted due to poor runoff water quality.

Today, the demands for mobile water treatment have tightened, and there are often strict discharge limits to adhere to. These requirements are likely to continue increasing. The issue of runoff water is becoming more prominent in construction projects, and since inadequate water treatment can now cause costly stoppages, there are incentives to prioritize effective, sustainable mobile water treatment.

Why is mobile water treatment important?

Dirty water from infrastructure projects and construction sites is a major source of pollution for Swedish watercourses. At the same time, infrastructure investments worth 100 million euros are planned in Western Sweden in the coming years, aimed at expanding and densifying the city of Gothenburg.

In January 2024, the government also decided that 10 major investment projects will commence construction between 2024 and 2026. This includes the reconstruction of the E45, E20, and E4 highways, as well as large, partially EU-funded projects, such as deepening the fairway in Gothenburg's port from 13.5 meters to 17.5 meters (Skandiaporten). Additionally, the upgrade of the Swedish railway network is in full swing, including the construction of the new 270 km coastal railway, the Norrbotniabanan, between Umeå and Luleå.

The number and scale of projects are increasing. The issue of managing and treating large amounts of dirty water has never been more important.

Historically, dispensations have been far too common and granted too easily, especially for municipalities with fewer resources. A 'bad solution' might involve using a treatment method that only provides good results for a short time, such as filter or infiltration solutions. Sometimes sedimentation containers are also used, which, due to large volumes, have no time to take effect and simply release the water again—essentially untreated.

Infiltration solutions often only work temporarily and can only handle a certain volume. During periods of heavy rainfall, such solutions always become problematic. The ground and excavated pits become saturated with water that needs to be pumped away and subsequently managed. The infiltration ceases to function entirely, and contaminated water may be released without treatment.

How to choose the right solution?

At Swedish Hydro Solutions, we actively work to build good relationships with clients, environmental authorities, and the contractors themselves. For us, it is about spreading knowledge on the importance of water treatment and engaging with all stakeholders in the industry, at all levels.

The industry's needs are clear:

• Better dialogue between clients, contractors, regulatory authorities, and water treatment companies

• Information on contaminated areas in advance

• Access to water samples—both in advance and over time

• Sufficient time for planning

• Better, specially designated areas for water treatment

• Simplified processes for adjusting threshold values

• Proper follow-up in the form of sampling and documentation

• Appropriate requirements for each unique site

When contractors plan for water treatment early in the project design, the positive outcomes are always significant. It becomes easier to estimate the volumes that need treatment, how much equipment is required, and how much space it will take.

In addition to the obvious environmental and safety benefits, choosing the right water treatment technology effectively ensures that contractors avoid costly downtime and issues with water in the excavations. If we at Swedish Hydro Solutions are involved from the planning stage, we can quickly work with our clients to find the right solution and scale it to the volume of water that needs treatment. This way, the production can continue smoothly without water becoming a problem.

We know that guidelines and requirements are forces that drive development and change. Swedish Hydro Solutions already has the technology needed to meet all European standards for sustainable mobile water treatment, based on the EU Water Framework Directive and the 2017 Weser Ruling.

However, at present, it is difficult to know which requirements apply, as the regulations vary so much.

Discharge requirements differ between regions and between different types of projects. Since the guidelines are vague, it is understandable that they are interpreted differently across the country's municipalities. The level of knowledge also varies.

A clear and unified regulatory framework would eventually lead to standardization, which would benefit the entire industry and reduce frustration among construction companies. Contractors would be able to estimate projects in the same way, regardless of where in the country they are to be carried out.

Swedish Hydro Solutions has participated in several projects to develop inexpensive and simple measurement technologies for continuous water monitoring at construction sites, including the partially EU-funded SCOREwater project. Such a monitoring system could give regulatory authorities better oversight and greater ability to set well-founded requirements for the quality of water released into the stormwater system.

This is how we can together build long-term sustainability and focus on working as environmentally safely as possible, instead of as cheaply as possible.