For states like Washington, Oregon, and parts of California, this meant drastic changes. During the rainy season, from October to April, it became prohibited to carry out land work if the water treatment capacity did not meet the required standards. This strict approach acted as a powerful driver for companies to develop new technology and improve their environmental performance.

Clean Water Act: a milestone in water treatment

A crucial factor for the USA’s progress is the Clean Water Act (CWA), which was introduced back in the 1970s. The CWA is the primary federal law regulating water pollution, aiming to restore and maintain the chemical, physical, and biological integrity of the nation's waters. It can be compared to the EU's Water Framework Directive, which came into effect nearly 30 years later, in the 2000s.

The Clean Water Act is one of the USA’s most influential environmental laws and has paved the way for extensive requirements in the construction and infrastructure sectors. It requires the use of approved purification technology, trained personnel, and clear results. In addition, the United States has introduced a unique level of transparency, where purification results from various projects are publicly available – something that is still lacking in Sweden.

Technological innovation: chitosan changed the game

One of the technological solutions that has had the greatest impact on water treatment is chitosan, a method developed in the USA in the late 1990s. John Macpherson, today a water treatment specialist at Swedish Hydro Solutions, played a key role in this development. He introduced chitosan as an effective solution to meet the stricter requirements in the USA’s construction and infrastructure industry.

Chitosan is a biodegradable product derived from crab shells and is a byproduct of the shellfish industry. Its molecular structure is similar to that of cellulose in plants. When chitosan is added to water, it causes small particles to aggregate, allowing them to settle more quickly. This makes it possible to treat large volumes of water in an efficient and environmentally sustainable way.

The method, which is classified as a Best Management Practice (BMP) in some U.S. states, quickly became a game-changer. Jakob Sjöberg, the founder of Swedish Hydro Solutions, who worked in the USA, later brought the technology to Sweden, where he further developed, simplified, and made it more cost-effective. Since 2016, chitosan has been successfully used in Swedish projects to meet the increased environmental requirements.

The synergy between legislation and technology

The USA’s success in water treatment is a clear example of how strict legislation can drive technological innovation and sustainable solutions. By setting high standards for the industry while enabling transparency and technological development, the country has become a role model in water treatment and addressing environmental challenges.

With chitosan and other innovative solutions, the USA has shown that it is possible to combine environmental consideration, efficiency, and economic sustainability.