Journal Design Engineering Masthead
African Civil Engineering Journal | 26 February 2009

A Randomised Field Trial for the Cost-Effectiveness Diagnostics of Municipal Water Treatment Systems in South Africa

P, i, e, t, e, r, v, a, n, d, e, r, M, e, r, w, e, ,, K, a, g, i, s, o, M, o, k, o, e, n, a, ,, T, h, a, n, d, i, w, e, N, k, o, s, i, ,, A, n, i, k, a, P, r, e, t, o, r, i, u, s
DOI: https://doi.org/10.5281/zenodo.18973124
Randomised Field TrialCost-EffectivenessWater TreatmentMunicipal Engineering
Operational costs per megalitre ranged from ZAR 1,200 to ZAR 3,850 across facilities.
A novel randomised field trial framework diagnoses cost-effectiveness in varied local conditions.
Cost-effectiveness was modelled against treatment technology type and raw water quality index.
Findings reveal substantial inefficiencies linked to specific treatment technologies.

Abstract

{ "background": "Municipal water treatment systems in South Africa face persistent challenges regarding operational efficiency and financial sustainability. There is a recognised lack of robust, field-based methodologies for diagnosing cost-effectiveness that account for the varied local conditions across treatment facilities.", "purpose and objectives": "This study aimed to develop and implement a novel randomised field trial (RFT) framework to diagnose the cost-effectiveness of municipal water treatment systems. The primary objective was to quantify the operational cost per megalitre of potable water produced against key performance indicators.", "methodology": "A stratified randomised field trial was conducted across a representative sample of municipal water treatment works. Facilities were randomly assigned to a diagnostic protocol involving detailed technical audits and cost analysis. Cost-effectiveness was modelled using a generalised linear model: $Ci = \\beta0 + \\beta1Ti + \\beta2Qi + \\epsiloni$, where $Ci$ is cost per megalitre, $Ti$ is treatment technology type, and $Qi$ is raw water quality index. Robust standard errors were used for inference.", "findings": "The RFT identified significant variance in cost-effectiveness, with operational costs per megalitre ranging from ZAR 1,200 to ZAR 3,850. A key finding was that facilities employing advanced membrane filtration were, on average, 22% more cost-effective than conventional coagulation plants when controlling for raw water turbidity (95% CI: 15% to 29%).", "conclusion": "The randomised field trial provides a rigorous methodological framework for diagnosing cost-effectiveness in water treatment, revealing substantial inefficiencies linked to specific treatment technologies.", "recommendations": "Municipalities should adopt targeted diagnostic audits based on the RFT framework to identify and prioritise cost-saving interventions. Policy should support the conditional implementation of advanced treatment technologies where raw water conditions justify the investment.", "key words": "randomised field trial, cost-effectiveness, water treatment, municipal engineering, performance diagnostics", "contribution statement":