| Company |
City |
State |
| S&R Environmental Consulting | Broomfield | Colorado |
| S&R Environmental Consulting | Denver | Colorado |
| Sacramento Regional Transit District | Sacramento | California |
| Safari Club International Foundation | Tucson | Arizona |
| SAGE Landscape Architecture & Environmental, Inc | Tucson | Arizona |
| SAIC | Oak Ridge | Tennessee |
| SAIC | Reston | Virginia |
| SAIC | Oak Ridge | Tennessee |
| Salem Community College | Carney's Point | New Jersey |
| Saltwater Inc. | Talent | Oregon |
| Saltwater Inc. | Anchorage | Alaska |
| San Carlos Apache Tribe | San Carlos | Arizona |
| San Diego County Air Pollution Control District | San Diego | California |
| San Diego Gas & Electric | San Diego | California |
| San Joaquin County | Stockton | California |
| San Jose State University | San Jose | California |
| San Mateo County, CA | Redwood City | California |
| Sanford Underground Science and Engineering Lab | Pierre | South Dakota |
| Santa Clara Valley Water District | Redwood City | California |
| Santa Clara Valley Water District | San Jose | California |
| Santa Lucia Conservancy | Carmel | California |
| Sapphos Environmental | Pasadena | California |
| Sarasota Bay Explorers | Sarasota | Florida |
| Save The Bay, Inc. | Providence | Rhode Island |
| Save the Manatee Club | Maitland | Florida |
| Save-the-Redwoods League | San Francisco | California |
| School for Field Studies | Salem | Massachusetts |
| Scientific Certification Systems | Emeryville | California |
| Scientific Certification Systems | Emeryville | California |
| Scott County | Shakopee | Minnesota |
| Sea Island Company | Sea Island | Georgia |
| Seattle Urban Nature Project | Seattle | Washington |
| Sebesta Blomberg | Roseville | Minnesota |
| Select Leaders | New York | New York |
| Sentech, Inc | Bethesda | Maryland |
| Severn Trent Services | Katy | Texas |
| Shaw Group Inc. | Baton Rouge | Louisiana |
| Shell | Los Angeles | California |
| Sierra Club | San Francisco | California |
| Sierra Club, San Francisco Bay Chapter | Berkeley | California |
| Sierra Nevada Alliance | South Lake Tahoe | California |
| Sierra Pacific Resources/Nevada Power | Las Vegas | Nevada |
| SJH and Company, Inc. | Boston | Massachusetts |
| Skelly and Loy, Inc. | Harrisburg | Pennsylvania |
| Sky Plus | san antonio | Texas |
| Smithsonian Institution | Washington | District of Columbia |
| Snake River Alliance | Boise | Idaho |
| SNEI | Las Vegas | Nevada |
| SNEI | Las Vegas | Nevada |
| Snohomish County Public Works | Everett | Washington |
| Sodexo | Gaithersburg | Maryland |
| Soil and Water Conservation Society | Ankeny | Iowa |
| Solar Planet, Inc | Columbus | Ohio |
| Sonoma County Water Agency | Santa Rosa | California |
| Soque River Watershed Association | Clarkesville | Georgia |
| South Branch Watershed Association | Flemington | New Jersey |
| South Coast Air Quality Management District | Diamond Bar | California |
| South Florida Water Management District | West Palm Beach | Florida |
| South River Federation | Edgewater | Maryland |
| South Yuba River Citizens League | Nevada City | California |
| Southern Alliance for Clean Energy | Knoxville | Tennessee |
| Southern Alliance for Clean Energy | Asheville | Southeastern USA |
| Southern Alliance for Clean Energy | Asheville | North Carolina |
| Southern Alliance for Clean Energy | Knoxville | Tennessee |
| Southern California Edison | Rosemead | California |
| Southern Energy Management | Morrisville | North Carolina |
| Southern Environmental Law Center | Charlottesville | Virginia |
| Southern Illinois University Edwardsville | Edwardsville | Illinois |
| Southern Oregon University | Ashland | Oregon |
| Southern Sustainable Agriculture Working Group | Fredericksburg | Texas |
| Southwest Florida Water Management District | Brooksville | FL |
| Southwestern Illinois College | Belleville | Illinois |
| SPG Solar | Novato | California |
| St. Johns River Water Management District | Palatka | Florida |
| St. Johns River Water Management District | Palatka | Florida |
| St. Johns River Water Management District | Palatka | Florida |
| St. Lawrence University | Canton | New York |
| Stanford University | Palo Alto | California |
| Stanford University | Stanford | California |
| Stanford University | Stanford | California |
| State of Illinois | Springfield | Illinois |
| State of Louisiana | Baton Rouge | Louisiana |
| State of Ohio | Columbus | Ohio |
| State of Oregon | Salem | Oregon |
| State of Tennessee | Nashville | Tennessee |
| State of West Virginia | Charleston | West Virginia |
| Stick Figure Production | New York | New York |
| Stony Brook University | Stony Brook | New York |
| Stonyfield Farm, Inc. | Londonderry | New Hampshire |
| Strategic Sustainability Consulting | Herndon | Virginia |
| Stratus Consulting Inc. | Boulder | Colorado |
| Student Conservation Association | Charlestown | New Hampshire |
| Suffolk County Water Authority | Oakdale | New York |
| Sustainable Conservation | San Francisco | California |
| Sustainable Design Consulting, LLC | Richmond | Virginia |
| SWCA | Phoenix | Arizona |
| SWCA, Inc. | Phoenix | Arizona |
| Sycamore Associates LLC | Walnut Creek | California |
| Synagro Technologies | Oconto Falls | Wisconsin |
| Synagro Technologies | Houston | Texas |
