Dear Emeka,

There may be discrepancies between water quality data collected by environmental agencies and citizen science data (this is often the case actually). Mainly because of differences in sampling methods, equipment, and data processing. EPAs use standard methods, while citizen science might be non-experts but experienced comunities (usually with limited resources). However, citizen science can complement agency data and increase spatial and temporal coverage.

Hope this helps!

Certainly, not all information obtained is accurate, we need accurate data and checks to prove the accuracy of the data

Attached is a BOOK REVIEW by Ghislain de Marsily (Académie des Sciences, Paris) devoted to the fundamental Water-Food Nexus in the Arid Region taking Tunisia as an example. "National water security– Case study of an arid country, Tunisia (Authors: Besbes, Chahed Hamdane), Euro-Mediterranean Journal for Environmental Integration (2019) 4:11". The Previous French version of the book is available in chapters on:

https://www.researchgate.net/publication/356650449_Securite_Hydrique_de_la_Tunisie_Preface_Introduction https://www.researchgate.net/publication/356662490_Les_Problemes_de_l'Eau_dans_le_Monde

https://www.researchgate.net/publication/356663902_Cinquante_ans_de_politiques_de_l'eau_1960-2010

https://www.researchgate.net/publication/356665641_Le_Bilan_Hydrique_National

https://www.researchgate.net/publication/356666107_Le_bilan_Hydrique_Integral_Eau_Bleue_Eau_Verte_et_Eau_Virtuelle

https://www.researchgate.net/publication/356666288_La_gestion_de_la_demande_en_eau_et_les_ressources_non_conventionnelles

https://www.researchgate.net/publication/356674959_Securite_Hydrique_de_la_Tunisie_les_questions_en_debat

https://www.researchgate.net/publication/356678805_Securite_Hydrique_de_la_Tunisie_Conclusion_Postface

Abstract:

This is a short review of a book recently published by Springer entitled: National water security–Case study of an arid country, Tunisia; by Mustapha Besbes, Jamel Chahed, and Abdelkader Hamdane. It shows that around 40% of the water consumed in Tunisia is imported as virtual water, used in other countries to produce goods. Water security is thus strongly linked to food security, but includes protection of the resource from pollution, accidents, malicious acts, and anticipation of extreme hydrologic events. A detailed analysis is made of water consumed by agriculture for food production by both rain-fed and irrigated crops, from which a surprising conclusion can be drawn: the major part of Tunisian food production is provided by rain-fed agriculture. Therefore, optimizing the yield of rain-fed agriculture becomes a priority. Alternative water resources are also discussed, as well as water governance. Results can be integrated into the policy choices related to sustainable water management which should be made in the future in Tunisia, and other regions where water is scarce.