The dataset provides detailed information on the study that was conducted in Lahore's 7 major towns. The sample was taken from 472 tubewells and analyzed for major cations and anions using APHA 2012 techniques as explained herein. Besides, E.coli determination was done to check for microbial contamination. The data includes results from PHREEQC modeling of As(III)/ As(V) species and saturation indices as well as Aquachem's computed hydrochemical water facies. The WHO (2011) and EPA standards included in Aquachem identified the parameters that where in violation. Bicarbonates dominated the groundwater types with 50.21% of the samples exceeding the EPA maximum permissible limit of 250 mg/L in drinking water. Similarly, 30.51% of the samples had TDS values greater than 500 mg/L while 85.38 % of the samples exceed 10 µg/L threshold limit value of arsenic. Also, instances of high magnesium hazard values were observed which requires constant assessment if the groundwater is used for irrigation. Higher than 50% MH values are detrimental to crops which may reduce the expected yields.The membrane filtration technique using m-Endo Agar indicated that 3.59% samples had TNC (too numerous to count) values for E.coli while 5.06% showed values higher than 0 cfu/ 100 ml acceptable value in drinking water. Any traces of E-coli in a groundwater sample indicate recent fecal contamination. Such outcomes signify presence of enteric pathogens. If the groundwater is not properly dosed with disinfectants it may cause harm to human health. It is concluded that more studies are needed and proper groundwater management implement to safeguard the lives of communities that depend solely on groundwater in the city.

EPA, Sec MCL levels: TDS = 500 mg/l; SO4, Cl and HCO3 = 250 mg/l; F = 2 mg/l; SAR = 9; MH = 50. WHO, 2011 levels: NO2 = 3 mg/l; NO3 = 50 mg/l; F = 1.5 mg/l; As = 10 µg/l.All physical and chemical analyses followed - APHA, AWWA, WEF, 2012. Standard Methods for the examination of water and waste water, 22nd edn. American Public Health Association, American Water Works Association and Water Environment Federation, Washington, DC.

Supplement to: Abbas, Zainab; Mapoma, Harold Wilson Tumwitike; Su, Chunli; Aziz, Syed Zahid; Abbas, Naaz (2018): Spatial analysis of groundwater suitability for drinking and irrigation in Lahore, Pakistan. Environmental Monitoring and Assessment, 190(7)