Our project is a 9 million SF Graduate University located in Saudi Arabia dedicated to the research of alternative fuels and renewable energy. The campus will consist of research labs, lab support areas, administration buildings, a library, a commons building, food service, an auditorium, conference rooms, lecture halls, offices and public areas. We will be seeking LEED NC Multi-Building / Campus Certification. An adjacent residential area is planned as part of the Master Plan, but will not be included in our LEED boundary for obvious LEED Certification system conflicts. The Campus will utilize efficient fixtures to reduce waste water conveyance and potable water use by 42%, shy of the 50% requirement for fixtures. All the remaining gray water and black water from the Campus is being collected and sent to a new local waste water treatment plant just outside of the LEED boundary for the Campus. The WWTP is being constructed as a local treatment system for the Campus and the surrounding residential areas, but is located just outside of the Campus LEED boundary. This WWTP is being constructed in close proximity to the Campus and residential area to avoid the extension of existing infrastructure. We are seeking compliance through Option #2 for this Credit: Treat 50% (100% for an Innovation in Design Point) of wastewater on-site to tertiary standards. Treated water must be infiltrated or used on-site. Although the WWTP is just outside our LEED boundary for Master Plan reasons, the intent of treating the Campus water and infiltrating it on-site is being met. The water is treated to tertiary standards at the WWTP and is then piped back to the Campus for all irrigation purposes. The Campus will use 100% recycled water from the WWTP for all irrigation needs and per the intent of the Credit, this will "increase the local aquifer recharge." The Campus will discharge 29,215,330 liters of water annually to the WWTP. 84,479,311 liters, from the Campus and the residential area will be treated and returned to the Campus boundary and infiltrated on-site as irrigation. Therefore, 100% of the waste water being generated within the project boundary is being treated to tertiary standards and infiltrated on-site, which in turn, increases the local aquifer recharge. Please advise if the project strategy meets the intent of the Credit.
The project team is inquiring as to whether or not they can use water treated to a tertiary standard from a wastewater treatment plant located just off-site of their campus to achieve potable water savings for wastewater use. Yes, the project can achieve this credit by using non-potable water from either on-site or municipally treated wastewater as stated in the LEED NCv2.2 Reference Guide. The water being used for this would need to be considered "reclaimed water", so therefore the term "tertiary standards" indicated in your request would need to be qualified with data showing that it meets the requirements stated in the LEED NCv2.2 Reference Guide defining Tertiary Treatment as; "the highest form of wastewater treatment that includes the removal of nutrients, organic and solid material, along with biological or chemical polishing (generally to effluent limits of 10 mg/L BOD? and 10 mg/L TSS)", but would not be considered potable or drinking quality water. The plant itself can be considered a municipal treatment plant. All other terms, conditions and requirements of the credit would need to be met upon submittal. Please note that gray water is not and does not come from any sewer wastewater treatment plant. Gray water by definition is raw, fresh, unfiltered, wastewater from specific human activities using potable water that does not and has not been in contact with black water or a toilet or urinal fixture. Applicable Internationally.
Related Addenda (Corrections & Interpretations)