Assessment of Water Quality Parameters and their Seasonal Behaviour in a Portuguese Water Supply System: a 6-year Monitoring Study

Abstract

Water quality monitoring is a fundamental tool in the management of freshwater resources. The purpose of monitoring is to provide meaningful quality data for local action planning and catchment-wide decision making. The assessment of water quality is crucial to guarantee the efficient operation of the Water Treatment Plants (WTPs), promoting health conditions and contributing for a more sustainable urban water cycle. In accordance, the objective of this study was to evaluate key target chemical and microbiological water quality parameters, some of them already monitored within Portuguese/EU legal framework and others still not regulated, but with environmental and human heath relevance. A local monitoring database model, using a 6-year period (from 2014 to 2019) of water quality data, regarding water samples collected on representative sampling locations covering the freshwater abstraction sites, conventional WTPs and distribution network was assessed. This work provides new knowledge regarding occurrence and seasonal behaviour for both microbiological and chemical water quality parameters, essential to understand/manage the water supply system. Additionally, relationships between the target variables were also assessed. Particularly, strong correlations were identified between TOC and THMs formation at distribution network (r = 0.69; p ≤ 0.001); nitrates were the water quality parameter that revealed the best correlation between surface water source and treated water (r = 0.81; p ≤ 0.001), suggesting that treatment yield/performance is dependent on surface water load. The local and continuous monitoring of water systems are crucial to implement new approaches to guarantee the best quality of drinking water throughout the supply system.

Trihalomethanes and physicochemical quality of drinking water in Addis Ababa, Ethiopia

“…This bromide might originate from the soil organic content (SOC), as indicated by a related study in which bromoform was the dominant THM produced during Cl2 treatment [ 52 ]. Furthermore, this distribution of THM species may be explained by the fact that bromine-carbon bonds are more resistant to dissociation than chlorine-carbon bonds due to lower dissociation energy [ 53 ].…”

Predictive capability of THM models for drinking water treatment and distribution

“…Water quality variable data were compiled through a literature review in Scopus. 18,19,23,[26][27][28][29][30][31][32][33][34][35][36][37][38][39] Search results were restricted to articles with titles or abstracts containing combinations of the words "trihalomethanes", "drinking water", and/or "model". Searches were further classified based on the inclusion of "treatment plant", "distribution system", "distribution network", "building plumbing", or "premise plumbing".…”

Monitoring Quality and Pollution Assessment of Groundwater for Drinking Purposes to Assure Sustainability

“…Water quality monitoring and evaluation are critical for ensuring the efficient operation of Water Treatment Plants (WTPs) and promoting health, and contributing to a more sustainable urban water cycle [26]. Twenty quality parameters are applied to samples collected from the pumping station before being pumped to the distribution network, as well as from the Tathleeth and Bishah networks.…”