A recent ruling by Washington’s State Pollution Control Hearings Board may force land developers in the Puget Sound area to use low impact development methods such as rain gardens and green roofs, instead of the traditional detention ponds. The ruling will affect the largest cities in the region and King, Pierce and Snohomish Counties. A second ruling, which would affect smaller cities in the region, is expected shortly. Local environmental groups had challenged the Washington State Dept. of Ecology’s National Pollutant Discharge Elimination System permit in front of the Environmental Hearings Board. The permit determines how local governments regulate storm water runoff. Federal law requires the permit to “reduce water pollution to the maximum extent practical.”