2023 Washington Code > Chapter 18.210 – On-site wastewater treatment systems — Designer licensing

2022 Washington Code > Chapter 18.210 – On-site wastewater treatment systems — Designer licensing

2020 Washington Code > Chapter 18.210 – On-site wastewater treatment systems — Designer licensing

2019 Washington Code > Chapter 18.210 – On-site wastewater treatment systems — Designer licensing

2018 Washington Code > Chapter 18.210 – On-site wastewater treatment systems — Designer licensing

2016 Washington Code > Chapter 18.210 – On-site wastewater treatment systems–Designer licensing

2015 Washington Code > Chapter 18.210 – On-site wastewater treatment systems–Designer licensing

2014 Washington Code > Chapter 18.210 – On-site wastewater treatment systems — Designer licensing

2013 Washington Code > Chapter 18.210 – On-site wastewater treatment systems — Designer licensing