# Water Quality Modelling, Monitoring, and Mitigation
## 4 Water Quality Mitigation Measures  
Water quality mitigation measures or strategies are generally intended to inform and assist communities in identifying potential alternatives to minimize the adverse impacts of pollutants on WQ and to ensure that water is safe for community use [25]. Ultimately, mitigation measures help to protect, restore, preserve, and improve the WQ of receiving water bodies. WQ protection refers to adequately treating runoff to protect downstream resources from WQ degradation [26]. Restoration comes into action if the protection strategies are not sufficient to maintain WQ standards as per the permissible limits. Stakeholders from different fields working together to achieve WQ restoration goals [27]. Water quality preservation necessitates a decision-support framework that can be used to evaluate, monitor, and optimize the effects of different drivers on WQ [28]. Furthermore, WQ improvements can be accomplished by identifying the highest priorities for WQ conditions and implementing mitigation strategies to address ongoing issues in a study area (Figure 2) [29; 30]. Sometimes, the study areas do not follow the jurisdictional boundaries; therefore, several stakeholders need to work together to achieve local/regional/national WQ goals. Water quality standards can be mitigated through regulation, remediation, and watershed management [31]. Water regulation in a specific area can control the free discharge of waste from industry or sewage treatment plants by setting standards for each pollutant released into surface waters [31]. Remediation acts, such as biological, chemical, and physical acts, help in cleaning the water contamination; (i) biological remediation is a cost-efficient method and is also called \"bioremediation\", which involves the use of naturally occurring organisms such as plants, bacteria, and fungi to remove or neutralize water pollutants and to breakdown hazardous substances into less toxic or nontoxic substances. Human sewage and agricultural chemicals that leach from the soil into the groundwater are generally treated by bioremediation [32; 33]. (ii) Chemical remediation methods use chemicals to react with the water contaminants to remove or make them less harmful, and (iii) physical remediation includes the removal of water contamination by treating it with filtration or disposing of it. Overall, all these three remediation methods are somehow complex, expensive, and difficult to adapt. Watershed management strategies consist of reducing the chemicals applied to land, making them more effective for nonpoint source pollution than setting pollution standards [3]. In a watershed, riparian areas promote WQ and limit pollution; therefore, their maintenance and restoration are crucial. Vegetation surrounded by a water body absorbs nutrients and provides shade to keep water cool and increase its capacity to hold dissolved oxygen (DO). Additionally, vegetation reduces runoff, promotes infiltration, and lowers soil erosion. Hence, vegetation plays a key role in the effective management of WQ through watershed management. Watershed practices that are beneficial for maintaining WQ standards include (i) regional infiltration basins; (ii) neighborhood-scale practices such as rain gardens, bioretention, and permeable pavement; (iii) stream restoration, including pooling and meandering to enhance infiltration; (iv) floodplain restoration, including floodplain benching; (v) stream (riparian) buffers; (vi) using park green space and fields to store and infiltrate water; (vii) stormwater-friendly post-construction design; and (viii) protecting and resting natural and human-made wetlands. Some important actions can be taken to get rid of polluted water before pollution ever happens and to mitigate WQ standards:  
* Avoid dumping waste in and around water bodies--dumping waste in water bodies leads to water pollution over a short period time. * Septic systems need proper maintenance and cleaning from time-to-time--leakage from septic tanks can cause groundwater pollution.