Trussell Technologies, 1939 Harrison Street, Oakland, California 94612, USA E-mail:
Colorado State University, Scott Bioengineering Building 246, Fort Collins, Colorado 80523, USA.
J Water Health. 2022 Oct;20(10):1558-1575. doi: 10.2166/wh.2022.135.
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 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.
利用本地水源（屋顶雨水、雨水、灰水和就地污水）满足非饮用水需求，可以最大限度地减少建筑物对饮用水的使用，并提高供水可靠性。2017 年，一个独立顾问小组制定了一个基于风险的框架，以确定就地非饮用水系统（ONWS）的病原体对数减少目标（LRT）。随后，加利福尼亚州的立法机构授权制定和采用包括基于风险的 LRT 在内的法规，用于多户住宅、商业和混合用途建筑。2021 年，一个加利福尼亚专家小组被召集，（1）使用新的定量病原体数据更新 LRT 要求，（2）提出能够满足更新后的 LRT 的处理方案。本文提出了针对多种病原体（病毒、原生动物和细菌）的更新的基于风险的 LRT，以及一套扩展的末端用途，包括厕所冲洗、衣物洗涤、灌溉、灰尘和消防抑制、洗车和装饰喷泉。对于每种水源、病原体和末端用途，更新后的 95%百分位 LRT 要求通常与 2017 年的 LRT 相差 1 个对数，无论使用何种方法来估计病原体浓度。LRT 要求随着废水、灰水、雨水和屋顶雨水等进水病原体浓度的降低而降低。成本和占地面积估算提供了有关就地污水系统实施的资本、运营和维护以及选址要求的详细信息。
