| Autor: |
Pecson B; Trussell Technologies, 1939 Harrison Street, Oakland, California 94612, USA E-mail: brianp@trusselltech.com., Kaufmann A; Trussell Technologies, 1939 Harrison Street, Oakland, California 94612, USA E-mail: brianp@trusselltech.com., Sharvelle S; Colorado State University, Scott Bioengineering Building 246, Fort Collins, Colorado 80523, USA., Post B; Trussell Technologies, 1939 Harrison Street, Oakland, California 94612, USA E-mail: brianp@trusselltech.com., Leverenz H; Department of Civil and Environmental Engineering, University of California, Davis, California 95616, USA., Ashbolt N; Faculty of Science and Engineering, Southern Cross University, Military Road, East Lismore, New South Wales 2480, Australia., Olivieri A; EOA, Inc., 1410 Jackson Street, Oakland, California 94612, USA. |
| Abstrakt: |
Using local sources (roof runoff, stormwater, graywater, and onsite wastewater) to meet non-potable water demands can minimize potable water use in buildings and increase supply reliability. In 2017, an Independent Advisory Panel developed a risk-based framework to identify pathogen log reduction targets (LRTs) for onsite non-potable water systems (ONWSs). Subsequently, California's legislature mandated the development and adoption of regulations-including risk-based LRTs-for use in multifamily residential, commercial, and mixed-use buildings. A California Expert Panel was convened in 2021 to (1) update the LRT requirements using new, quantitative pathogen data and (2) propose treatment trains capable of meeting the updated LRTs. This paper presents the updated risk-based LRTs for multiple pathogens (viruses, protozoa, and bacteria) and an expanded set of end-uses including toilet flushing, clothes washing, irrigation, dust and fire suppression, car washing, and decorative fountains. The updated 95th percentile LRTs required for each source water, pathogen, and end-use were typically within 1-log 10 of the 2017 LRTs regardless of the approach used to estimate pathogen concentrations. LRT requirements decreased with influent pathogen concentrations from wastewater to graywater to stormwater to roof runoff. Cost and footprint estimates provide details on the capital, operations and maintenance, and siting requirements for ONWS implementation. |
