## 1 Introduction
Water quality in the recharge zones is considered adequate for domestic and agricultural use; however, storage and discharge areas register high As concentrations [18; 19] and large amounts of sodium hypochlorite, used in the disinfection of water collected in deep wells causing a chlorine odour and taste, which can cause health problems such as chest pain, vomiting, breathing difficulty, etc. The above demonstrates the degree of the hydraulic distribution system contamination in the region coupled with soil contamination. In addition to water pollution in the region, other factors cause major water shortages, including limited precipitation coupled with population growth in the area. Annual rainfall in the region is 400 mm with annual evaporation that fluctuates between 1600 and 2000 mm [7]. The population in 2000 was 64,206 inhabitants with a volumetric water production of 6,274,629 m\({}^{3}\); by 2017 the number of inhabitants had grown to 99,015 with a volumetric water production of 6,641,262 m\({}^{3}\). Water service demand grew from 18,159 water intakes in 2000 to 28,776 in 2018. Inhabitants most affected by water shortage are rural communities and vulnerable sectors within the city [20]. Government strategy has focused on the exploration and creation of new deep wells affecting the groundwater table; for example, in 2014, approximately 262,000 USD were investedin drilling deep wells, of which 30% failed. Therefore, it is necessary to look for alternatives to supply freshwater without affecting the environment and with adequate conditions for human consumption or use in other activities. At a global level, various strategies have been presented to reduce water scarcity, specifically in the improvement of hydraulic distribution systems (storage, distribution, and irrigation systems), rainwater harvesting, seawater desalination technologies, water management, and atmospheric water harvesting [21; 22; 23; 24; 25; 26; 27; 28; 29]. From the latter, fog and dew are major sources of water for arid regions [30]. Dew is formed through two main steps: (1) Nucleation of a liquid phase forming a droplet on an obstacle, and (2) growth of the droplet at the expense of the surrounding atmosphere [31; 32]. Based on the foregoing, various technologies have been developed for water harvesting, such as (i) salts or desiccants (liquids, solids and compounds) operating on various energy sources [33; 34; 35; 36], (ii) smart materials such as bioinspired materials, nanostructured materials, gels and hydrogels [21; 37; 38], (iii) radiative cooling (Radiator-Condensers) by emitting thermal infrared radiation to the cold universe through the atmospheric window [39; 40] and (iv) direct cooling by commonly using conventional vapour compression (VC) refrigeration systems or other cooling technology [2; 41; 42]. This last method consists of cooling the air humidity mixture to a temperature below dew point, causing moisture condensation and water harvesting, which depend on atmospheric air, a huge and renewable water deposit. There are approximately 3100 cubic miles of water in the atmosphere, 98% of which are in the form of vapour, and 2% in the form of clouds. It is known that about 280 cubic miles of water evaporate or transpire daily into the atmosphere, and the amount of water in atmospheric air is about 14,000 km\({}^{3}\) compared to only about 1200 km\({}^{3}\) of fresh water on earth [41]. Devices that harvest water from the atmosphere are called atmospheric water generators (AWGs) and can be used successfully both in arid areas with low moisture content and in humid areas with high moisture content [22; 43; 42]. In this work, we present a feasibility study on the use of atmospheric water generators (AWGs) for harvesting atmospheric air water in the region of Matehuala, SLP. This area has high levels of As contamination from mining and metallurgical activities.