Saudi wastewater reuse standards for agricultural irrigation: Riyadh treatment plants effluent compliance

In 2006, standards for wastewater reuse in agricultural irrigation were issued by the Ministry of Water and Electricity (MWE); these replaced the 2003 standards issued by the Ministry of Municipal and Rural Affairs (MMRA). Herein, a review of the current Saudi Arabian policies is presented. Effluent quality from six largest sewage treatment plants in Riyadh, Saudi Arabia was monitored for 10 months; the results are reported in this paper. Further, plant information are presented, effluent quality data, and their conformity to the recent standards are discussed. Upon analysis of the results, all of the studied plants produced effluents of acceptable quality, with only minor violations for restricted agricultural irrigation (RI); the effluents did not conform to the unrestricted agricultural irrigation (UR) standards. According to this study, standards for RI adopted are stringent and might be not suitable for local plants and either reviewing the standards or actions for upgrading the treatment processes are needed to overcome this violation. This raises the importance of adapting suitable standards for the local conditions without violating the public health requirements.