Combination Campus / On-site approach?

I'm working on a Canadian, CAGBC LEED NC 2009 project that is located with a business park. The business park's water treatment system, a constructed wetland, preceded by two vortex separators, was intended to be designed to meet LEED standards for quality and quantity control. However, there was limited space available for the pond and facilities, and the development was allowed to go forward with a system designed to achieve 77% removal of TSS. My client's site incorporates a rainwater harvesting system and bioswales, such that the overall treatment of water coming from their site will be significantly above the required 80% removal of TSS. Installing further on-site treatment is not an affordable option and would duplicate the downstream treatment being provided by the campus facilities already installed. However, in all the credit interpretation requests I can find in the US or Canadian system, it seems that either 1) all the treatment must be done on site, or; 2) the entire campus must be treated to the 80% removal rate. There is no policy in place at the campus level requiring each developer to make up the additional 3% TSS treatment on their site; it would be up to each developer to make the choice to do so. Does anyone have any experience with this kind of a situation? Is it worth submitting a CIR to determine if this combined approach to treatment is acceptable?