It was not enough to address the impacts of the additional impervious area through design and contruction alone. We needed to ensure the implentation of our practices worked.
When we were complete, we deployed automatic storm water runoff samplers that capture water samples during rain events such that we can analyze them for phosphates, nitrogen, total disolved solids, and alkalinity. We continually compare those metrics with our predevelopment baseline to ensure that each facility is working as designed. Operationally, we agreed to vacuum the parking fields each and every day as our first line of defense in removing adverse particulate from our storm water runoff.