ID#5951 made on
SSc6.2 - Stormwater management - treatment
LEED BD+C: New Construction
This inquiry pertains to a LEED project that is part of a 5-city block urban redevelopment. In close collaboration with city permitting authorities and our civil engineer, we have purchased and insta...
This inquiry pertains to a LEED project that is part of a 5-city block urban redevelopment. In close collaboration with city permitting authorities and our civil engineer, we have purchased and installed a prefabricated-district- stormwater treatment system manufactured by "CDS Technologies" which treats the stormwater coming off all 5 blocks. This unit was installed on a storm water sewer extension that connects to the interceptor sewer downstream of a combined storm/sanitary diversion and discharges directly into the Willamette River. Thus none of the storm water from the development impacts the capacity of the sewage treatment plant. The CDS Technologies Water Quality Manhole is designed to remove 90 percent of Total Suspended Solids (TSS), and 30 percent of total phosphorus (TP). The LEED requirement is 80 percent TTS and 40 percent TP. There is no conventional landscaping at the site (other than street trees), and landscape fertilizer will not be used. Since neither a permanent irrigation system nor any kind of regular fertilizer application is necessary, TP levels at the site will not increase in the future. There are no EPA Maximum Contaminant Levels (MCLs) for phosphorus in groundwater, and the State of Oregon Department of Environmental Quality does not regulate phosphorus in runoff. Therefore, we propose that by reducing TP by 30 percent and removing 90 percent of TSS (exceeding the LEED requirement by 10%), we meet the intent of Sustainable Sites Credit 6.2. Question 1. We submit that by exceeding the TS requirement, which is a greater problem in this area than TP, we have met the intent of the credit even though our system does not meet the TP requirement. (We will, of course, provide cutsheets and schedules documenting these numbers, per the credit requirement.) Please confirm. Question 2. Because the CDS Technologies Stormwater Quality Manhole was paid for by each of the various current and future LEED registered projects within this redevelopment and this is a credit in the Sustaining Sites category, we seek confirmation from USGBC that we can capture this credit for each LEED project at this site. Please confirm.
Question 1: Yes, your project meets the intent of the credit. Along with your other required documentation of cut sheets, drawings and specifications, you should also provide a letter from the building owner along with your LEED application documenting the lack of phosphates entering the site. Please see the answer to next question for further information required. Question 2: Yes, the system you describe could be counted for each building if you can show that the system is capable of treating the stormwater as described, and has the capacity to remove the required contaminants for ALL buildings.
Related Addenda (Corrections & Interpretations)