Scoring Methodology — Agua Costa del Sol Water Quality

Overview

Each municipality and each individual water network is assigned three sub-scores — Safety, Hardness and Taste & Comfort — each on a scale from 0 to 10. These are combined into a weighted overall score:

🛡️ Safety — 50% weight: bacteria, heavy metals, nitrates, pesticides and other health-critical parameters
💎 Hardness — 25% weight: dissolved minerals that affect appliances and taste
👅 Taste & Comfort — 25% weight: pH, chlorine, turbidity, odour, colour and related parameters

A score of 10 = ideal. A score of 0 = at the legal maximum. 0 does not mean unsafe — the authoritative indicator is the official SINAC certification (APTA / NO APTA). Only readings from the last year are included.

Safety Parameters (50%)

Parameter	Legal limit	Scoring method
E. coli	0 UFC/100ml	10 if zero, 0 if detected
Enterococci	0 UFC/100ml	10 if zero, 0 if detected
Coliform bacteria	0 UFC/100ml	10 if zero, 0 if detected
Nitrate	50 mg/L	Linear: 10→0 as value→limit
Nitrite	0.5 mg/L	Linear
Lead	10 µg/L	Linear
Arsenic	10 µg/L	Linear
Mercury	1 µg/L	Linear
Cadmium	5 µg/L	Linear
Chromium	50 µg/L	Linear
Nickel	20 µg/L	Linear
Trihalomethanes (THMs)	100 µg/L	Linear
Total pesticides	0.5 µg/L	Linear
Uranium	30 µg/L	Linear

Linear scoring: score = 10 × (1 − value ÷ limit). At 0 concentration, score = 10. At the legal limit, score = 0.

Hardness Parameters (25%)

Parameter	Legal limit / reference	Scoring method
Water hardness (CaCO₃)	No legal limit	Tiered: ≤100=10, ≤200=8, ≤300=6, ≤400=4, >400=2
Conductivity	2500 µS/cm	Linear above 500 µS/cm
Chloride	250 mg/L	Linear
Sulphate	250 mg/L	Linear
Sodium	200 mg/L	Linear
Fluoride	1.5 mg/L	Linear

Taste & Comfort Parameters (25%)

Parameter	Reference	Scoring method
pH	Optimal 7.0–8.0	10 in optimal range, tapers to 0 at extremes
Turbidity	4 NTU	Linear
Chlorine	0.2–1.0 mg/L required	Peak at 0.2–0.5 mg/L
Odour	3 (dilution index)	Linear
Taste	3 (dilution index)	Linear
Colour	15 mg Pt-Co/L	Linear
Aluminium	200 µg/L	Linear
Iron	200 µg/L	Linear
Manganese	50 µg/L	Linear
Ammonia	0.5 mg/L	Linear

Data pipeline

Scrape: Fetches current network data from SINAC via HTTP POST requests
Score: Applies scoring formulas to each measured parameter for each network
Aggregate: Calculates weighted averages per municipality
Generate: Builds static HTML for all 60+ pages (4 languages)
Deploy: Publishes to Cloudflare Pages

Legal limits reference EU Drinking Water Directive 2020/2184/EU as implemented by Spanish Royal Decree 3/2023.