Test facility for prefabricated storm water treatment devices.

In Sweden, stormwater management has usually implied release of stormwater into the nearest recipient with no concern for either the levels of contaminants in the water or to the sensitivity of the recipient. The demand for sustainable solutions has increased along with more knowledge concerning stormwater toxicity and the harmful effects it can have on the environment in the long term. New technical solutions for stormwater treatment are continuously being presented on the market, however, independent third-party tests have rarely been conducted to verify the function of these solutions. To choose the right technology for a specific application while ensuring the function over an extended period of time, can therefore be complex task for customers. Likewise, the variety of requirements on treatment efficiency makes in challenging for technology suppliers as there is currently no possibility of independent testing of stormwater treatment devices in Sweden to verify this. As a step towards a more sustainable stormwater management, RISE developed a proposal for a national standard for prefabricated treatment devices within a Vinnova-funded project in 2019. Subsequently, the Swedish Environmental Protection Agency has financed three follow-up projects where this is the latter of the three. The aim for this project has been to answer the remaining questions and create sufficient knowledge to be able to build the test bed in a next step. During the project, a lot of valuable information has been gathered through interviews, dialogues, a workshop and a survey with actors from both the customer side and the supplier side in Sweden and internationally. The design of the test bed has emerged and is based on the proposed standard and the input that has come along the project. A business model has been developed, where different alternatives have been studied. Based on this, ways forward have been discussed. The conclusions of the project can be summarized by the fact that the need for a clearer definition of requirements for stormwater quality and a national standard for third-party tests of stormwater treatment devices is great both from customers and technology suppliers. Based on the dialogues conducted with international actors, it has emerged that several countries (e.g., Germany and the UK) have come further than Sweden in this area and there is much to be gained from continuing the dialogue and cooperate further on these issues. The business model shows that a mobile facility is preferable, as the area of use can then be broadened and revenues for rent can supplement income from standardized tests. However, this means that only smaller facilities can be evaluated in the facility, which several technology providers have been critical of. One possibility that have been discussed within the project is that larger facilities could be evaluated according to a Swedish standard at an established test bed abroad. For standardized tests, the cost estimate is SEK 200,000 towards the customer, to also get coverage for inactive periods. If the investment cost of the test bed can be financed in another way, for example through national grants, depreciation costs are reduced by approximately SEK 10,000 / week, which contributes to reduced costs per test and rental period. This would give more technology providers the opportunity to perform tests, as well as enable an expanded knowledge building, which would benefit the industry as a whole.