1. Introduction
Proper control of residual chlorine in drinking water systems is one of the essential sanitary practices to guarantee the microbiological safety of the water resource (Angassa et al., 2025). The presence of residual chlorine constitutes an indispensable sanitary barrier to inactivate pathogens that can proliferate within distribution networks, especially in areas where infrastructure is deficient or where there are prolonged storage periods (Arzovs et al., 2025). In rural contexts, where topographical conditions and technical access are often limited, sanitary monitoring of residual chlorine becomes even more relevant, since small variations can be associated with contamination events or failures in chlorine dosing (Burnet et al., 2025).
In Peru, drinking water quality regulations require maintaining minimum concentrations of 0.5 mg/L at the most remote points in the network to ensure the continuous protection of the water resource (Chiu et al., 2022). However, several studies have reported that Water and Sanitation Management Boards (JASS) face difficulties in complying with this requirement due to a lack of specialized equipment, limited financial resources, and reliance on manual methods that do not allow for constant monitoring (Ding et al., 2025). This situation creates operational gaps that can compromise the capacity to respond to chlorination loss events.
The literature indicates that chlorine variability in rural networks is due to multiple factors, including hydraulic retention time, the presence of organic matter, pipe length, temperature changes, water quality at the intake, and variations in dosage by system operators (Durgun, 2024). Each of these conditions can accelerate the demand for chlorine, causing insufficient concentration at the terminal points, where sanitary non-compliance commonly occurs.
This problem is exacerbated when measurements rely exclusively on colorimetric kits, whose ability to detect subtle changes is limited and subject to operator perception, which can introduce subjective variability into the readings (Elsherif, Taha, and Abokifa, 2024). In the case of Sinsicap, historical measurements reveal that the frequency was low and that, on some days, the information was nonexistent; this prevented continuous evaluation of chlorine behavior in the network and hindered informed decision-making for adjusting dosage.
In response to these limitations, the scientific literature has promoted the use of low-cost digital sensors as a technological alternative to improve continuous residual chlorine monitoring, due to their accuracy, stability, and accessibility (Fan and Gurtler, 2024; Fashina et al.). (2023). Recent research shows that these sensors allow for multiple daily measurements, recording hourly variations and early detection of risk situations, such as sudden decreases in chlorine or dosing failures Fonseca-Revelo, Fonseca-Revelo and Cerón-Correa (2024).
The development of the prototype designed for Sinsicap incorporated technical and operational principles documented in smart monitoring studies, integrating digital sensors, a specific PCB board, an SD card storage system, and an LCD screen for instant readings. This architecture allowed for the creation of a self-contained unit that is easy to install and adaptable to strategic points in the network. The selection of the reservoir, initial housing, intermediate housing, and final housing points addresses the need to characterize the progressive chlorine loss associated with distance and water transit time within the system, as described in sanitary engineering research on rural systems.
Furthermore, the socio-organizational context of the Sinsicap Water and Sanitation Management Board (JASS) also influenced the prototype selection, as the goal was to develop an accessible, economical, and replicable tool that did not depend on sophisticated infrastructure or highly specialized personnel. This approach is consistent with the technological sustainability guidelines applied in rural regions of the country, where operational and maintenance capacity must be compatible with the resources and skills of local personnel.
The importance of this study lies in demonstrating that implementing a continuous chlorine monitoring system based on low-cost technology can significantly improve operational management, enabling the identification of trends, comparison of methods, validation of behaviors, and informed decision-making regarding chlorine dosage. Furthermore, the evidence generated allows for contrasting the effectiveness of the prototype with traditional methods, evaluating technical parameters such as stability, frequency, accuracy, and reproducibility of measurements.
Within this framework, this article aims to evaluate the influence of the low-cost prototype on residual chlorine monitoring in the Sinsicap drinking water system. This involves integrating pre- and post-intervention comparative analyses, technical validation of the sensor, and statistical analyses to determine the significance of the observed changes, following the methodologies proposed by Fuentes Amín and Romero Torres (2024) and Hamel et al. (2024). In this way, scientific evidence is provided to support the use of accessible technologies as viable and sustainable alternatives for improving drinking water quality in rural communities.