The ability to aptly and accurately apply environmental models is key when it comes to answering both simple and complex site-related questions. Windward has extensive experience in using such models, both to address specific regulatory requirements—such as effluent permit limits—and in support of site-specific evaluations—such as risk assessments. The benefits of using environmental models are many. These models can be applied to evaluate prospective scenarios at a site, such as using a fate and transport model to identify potential remedial alternatives. Costs savings are another advantage: Rather than studying an entire site, Windward is able to collect input data at select locations within a study area, a much less expensive process than initiating site-wide data collection. Once these select data have been used in the model, the model can be applied to the entire site. Similarly, the use of bioavailability and toxicity models for metals allows for the application of a site-specific evaluation, which is much more cost effective than the toxicity laboratory costs that would otherwise be necessary.