Implementation of Erosion Control Warranty Specification

One of the main issues in a warranty specification for erosion control items is how to evaluate performance objectively. This project developed a methodology that uses digital images to measure compliance with defined vegetation cover requirements. It is designed essentially for areas where vegetation (grass) is selected as the erosion control measure. The research was a technical approach to examine the feasibility of using digital photographic analysis. It does not address all issues related to field conditions and as such would require review by interested parties to be complete. For example, how often should sample pictures to taken. Should a random selection process be developed similar to ones currently used to sample asphalt materials? What criteria should be used to elect when the technical process becomes binding to both parties etc. and what wording in the warranty provision should be used? Additional items include who makes the inspection and how do they become trained in the process and become equipped with the necessary camera and light meter. This project provides some technical answers with using this approach. Due to some of the uncertainties discovered with using warranty erosion control on three INDOT projects it was decided to take a cautious approach to implementing this provision. Therefore the findings are being disseminated to the Erosion Control Committee for further consideration and action.