Characteristics of literature
After removing the duplicates, 2119 documents were reviewed based on titles and abstracts (Fig. 1). The full texts of 227 relevant papers were retrieved. Finally, 76 papers were selected according to inclusion criteria. The articles were divided into two categories. The first category articles include Strategies for water pollution control based on advanced technology (Table 1). The second category articles have Policies and regulations for water pollution control based on different geographical locations (Table 3). Of 86 final articles selected, 43 were placed in the first category and 33 in the second category.
Characteristics of the retained studies
Table 2 summarises the strategies for water pollution control based on different advanced technology. The articles were further grouped into strategies (n=2) and technologies (n=40) within this table. Among 42 pieces, the summarised studies selected for each technology was as follow: Electrodialysis to remove arsenic from water (n=1), Atomic layer deposition (ALD) for aquatic remediation, UV/H2O2 treatment, Hydrogen peroxide for cyanobacteria removal, Seaweeds as a source of the bioactive compound for cyanobacteria, Safranine O Dye removal by sawdust, dye removal by arnchis hypogaca, pyrolysis treatment for bioenergy, water hyacinth, phosphorus elimination plant, graphic carbon nitrite (n=3), bio-manipulation and adsorption technology, modified clay (Floc and Sink), carbon absorption, aquatic vegetation restoration, metal sulphides base advanced oxidation process, bio-remediation (n=1) and removal of chromium from wastewater by electrochemical approach (n=1). The two strategies included ‘333’ integrated strategy in China and wetland construction (n=1).
Among 33 articles classified in the second category (policies and regulations), the summarised number of articles based on different geographical locations was as follows: (See Table 3) China (n = 5), USA (n = 6), India, Ethiopia, Australia, Israel (n = 2), Germany (n = 4), Japan, Netherlands, South Africa, Sweden, Singapore, Burkina Faso, Malaysia, Canada, Pakistan (n = 1). An article covered two European countries.
Table 2
Strategies for water pollution control based on different advanced technology
Strategy/Technology | Study & publication year Reference |
Toxicity, Detection, and Removal of Chromium in Water and Wastewater | (Sharma and Singh 2020) |
Biosorption of Safranine O Dye by Saw Dust | (Saroha and Ghosh 2020) |
Biosorption of Safranin-O Dye by Shell of Arachis Hypogaea | (Panchal and Ghosh 2020) |
Manure-borne pathogens as an important source of water contamination: An update on the dynamics of pathogen survival/transport as well as practical risk mitigation strategies | (Oluwadara and Anderson 2020; Alegbeleye and Sant’Ana 2020) |
Wastewater-to-energy practices for sustainable urban water pollution control | (Huang et al. 2020) |
Removal of Phenolic Compounds from Water Using Sewage Sludge-Based Activated Carbon Adsorption | (Mu’azu et al. 2017) |
Water Pollution Control for Sustainable Development | (Deletic and Wang 2019) |
Recent Advances in Arsenic Research: Significance of Differential Susceptibility and Sustainable Strategies for Mitigation | (Sanyal et al. 2020) |
The ‘333’ integrated strategy for effective pollution control and its application to the heavily polluted Jialu River in north China | (Huang et al. 2018) |
Water quality management of aquifer recharge using advanced tools | (Lazarova et al. 2011) |
Recent advances in wastewater treatment through transition metal sulfides-based advanced oxidation processes | (Li et al. 2021) |
Aquatic environment remediation by atomic layer deposition-based multifunctional materials: A review | (Li et al. 2021) |
Fouling in membrane bioreactors: An updated review | (Meng et al. 2017) |
A review of the use of sonication to control cyanobacterial blooms | (Rajasekhar et al. 2012) |
Removal of Cyanobacteria and Cyanotoxins in Waters | (Serrà et al. 2021b) |
‘Floc and Sink’ Technique Removes Cyanobacteria and Microcystins from Tropical Reservoir Water | (Arruda et al. 2021) |
Removal of Positively Buoyant Planktothrix rubescens in Lake Restoration | (Lürling 2020) |
Enhanced Photocatalytic Removal of Cyanotoxins by Al-doped ZnO Nanoparticles with Visible-LED Irradiation | (Benamara et al. 2021) |
Kinetics of Microcystin-LR Removal in a Real Lake Water by UV/H2O2 Treatment and Analysis of Specific Energy Consumption | (Sorlini et al. 2020) |
The Efficacy of Hydrogen Peroxide in Mitigating Cyanobacterial Blooms and Altering Microbial Communities across Four Lakes in NY, USA | (Lusty and Gobler 2021) |
Seaweed Essential Oils as a New Source of Bioactive Compounds for Cyanobacteria Growth Control: Innovative Ecological Biocontrol Approach | (Zerrific et al. 2020) |
Large-Scale Green Liver System for Sustainable Purification of Aquacultural Wastewater: Construction and Case Study in a Semiarid Area of Brazil (Itacuruba, Pernambuco) Using the Naturally Occurring Cyanotoxin Microcystin as Efficiency Indicator | (Esterhuizen and Pflugmacher 2020) |
Rationally designed conjugated microporous polymers for contaminants adsorption | (Sheng et al. 2021) |
Seeking a compromise between pharmaceutical pollution and phosphorus load: Management strategies for Lake Tegel, Berlin | (Schimmelpfennig et al. 2012) |
Metal-Organic Frameworks and Their Derived Materials: Emerging Catalysts for a Sulfate Radicals-Based Advanced Oxidation Process in Water Purification | (Wang et al. 2019) |
Application of constructed wetland for water pollution control in China during 1990–2010 | (Zhang et al. 2012) |
Emerging graphitic carbon nitride-based membranes for water purification | (Cui et al. 2021) |
Recent advances in single-atom catalysts for advanced oxidation processes in water purification | (Huang et al. 2021) |
Nanomaterial-Supported Enzymes for Water Purification and Monitoring in Point-of-Use Water Supply Systems | (Wang et al. (019) |
Biomimetic super-lyophobic and super-lyophilic materials applied for oil/water separation: a new strategy beyond nature | (Wang et al. 2015) |
Removal of organic pollutants in water using water hyacinth (Eichhornia crassipes) | (Madikizela 2021) |
Field testing of a household-scale onsite blackwater treatment system in South Africa | (Sahondo et al. 2020) |
Heavy Metal Pollution and Its Eco-friendly Management | (Rathoure 2019) |
Eco-Remediation Technologies | (Qu and Fan 2010; (Sysoeva and Gelmanova 2021) |
Aquatic Vegetation Restoration Technology | (Sean et al. 2017; Geist and Hawkins 2016) |
Bio-Manipulation Technology | (Desai et al. 2007) |
Floating Aquatic-Plant Bed Systems | (Kırım et al. 2014; (Deng and Ni 2013; Li et al. 2010) |
Wetlands Rehabilitation Technology | (Wang et al. 2020) |
Removal of Chromium Using Electrochemical Approaches: A Review | (Zhao et al. 2018) |
Using Sawdust to Treat Synthetic Municipal Wastewater and Its Consequent Transformation Into Biogas | (Abudi 2018) |
Efficiency Of Sawdust Adsorbent in Water Treatment | (Familusi et al. 2018) |
Treatment of high arsenic content wastewater by a combined physical-chemical process | (Abudi 2018) |
Removal of Dyes from Wastewater using Adsorption - A Review | (Sivamani and Leena 2009) |
Adsorptive removal of antibiotics from water over natural and modified adsorbents | (Eniola et al. 2019) |
Adsorption Technology | (Qu and Fan 2010) |
Table 3
Policies and regulations for water pollution control based on different geographical locations
Country | Location | Time Period Covered | Policy/Regulation | Study & publication year, Reference |
| | | Water Pricing Policy as Tool to Induce E efficiency in Water Resources Management | (García-López, Montano and Melgarejo 2020; |
China | | 2015 - 2030 | Action Plan for Water Pollution Prevention | Zhou et al. 2021) |
| Macau | | Integrated water resources management for emergency situations. | (Lou,and Li 2016; Ni 2016) |
| | | Transfer Payment of Ecological Functional Areas Policy (TPEFAP) | (Pan and Tang 2021) |
| Chaohu | | River Chief Policy for Water Pollution Control | (Xu et al. 2020; Liu et al. 2019) |
| | 2006 - 2010 | 11th Five-Year Plan for Water Resources Development (FYPWRD) | (Lan et al. 2013; Jiang 2009) |
Sweden | | | Complex governance structures and incoherent policies: Implementing the EU water framework directive in Sweden | (Soderberg 2016) |
USA | | | National Pollution Discharge Elimination System (NPDES) | (Iho et el. 2015) |
| | 1972 | Clean Water Act: A Summary of the Law | (Copeland 2018) |
| Colorado | 1984 | Water Pollution Control Policy: Total phosphorus standard developed in 1984 for Cherry Creek | (Rahman 2014) |
| | | Biological Monitoring and Abatement Program (BMAP) | (Loar et al. 2011) |
| Iowa | 1986 - Date | Iowa Nutrient Reduction Strategy (INRS) to reduce total nitrogen and phosphorous loads by 45% by 2035 | (Rundhaug et al. 2018) |
| | | The low but uncertain measured benefits of US water quality policy. | (Keisera et al. 2018) |
Singapore | | | Singapore Water Management Policies and Practices | (Luan 2010) |
Burkina Faso | Upper Comoe | | Integrated Water Resource Management in the Upper Comoe´ River Basin, Burkina Faso | (Roncoli et al. 2009) |
Japan | | 1977 | Guidance for Introducing the Total Pollutant Load Control System (TPLCS) | (Tomita et al. 2016; Japan Ministry of Environment 2011) |
Ethiopia | | 2002 | Environmental Pollution Control Proclamation | (Awoke et al. 2016) |
| | 2001 | Ethiopian Water Sector Policy | (IRC 2019) |
Australia | New South Wales | 1992 | Water Pollution Control Policy: Addressing Non-Point Source Pollution | (Rahman 2014) |
| New South Wales | 1995 | Salt Pollution Trading Case: Hunter River | (NSW 2006) |
Canada | Ontario | 1998 | Phosphorous Trading in the South Nation River Watershed, Ontario | (Grady 2008) |
South Africa | | | Water Pollution Control Laws in South Africa | (Nkosi and Odeku 2014) |
India | | 2003 | The Water Prevention and Control of Pollution Cess Act | (Raju and Taron 2016) |
| | 1985 | India’s National River Conservation Plan (NRCP) | (Nallathiga, 2008) |
Israel | | | Water Pollution Control Legislation in Israel | (Hophmayer-Tokich 2013) |
| | 1991 | ISRAEL - Water Regulations (Prevention of Water Pollution) (Spraying Near Water Sources | (FAO 2016) |
Malaysia | | 1974 | Environmental Quality (Sewage) Regulations 2009 | (Ariffina and Sulaiman 2015) |
Pakistan | | 2001 | Pollution of Water Bodies: Pakistan Wetlands Programme (PWP) | (Cooper 2018; EPD 2007) |
Germany | | 1996 | Pollution control regulations in Germany: the Federal Water Resources Act (Wasserhaushaltsgesetz) (WHG) | (Enderle and Müller-Gschlössl 2018) |
| | 2015 - 2020 | EU’s Common Agricultural Policy (CAP) | (Environmental Agency 2018) |
| | 2010 | The Industrial Emissions Directive: “Zero Liquid Discharge” at the Smurfit Kappa Zülpich paper factory | (Zettl 2018) |
| | 2000 | Water management in cities of the future using emission control strategies for priority hazardous substances | (Eriksson 2011) |
Table 4
Summary of technology type, Pollutant and Sources of Pollution
Technology | Pollutant | Source of Pollution | Reference |
Electrodialysis | Chromium | Municipal sewage | (Zhao et al. 2018; Sharma and Singh 2020) |
Biosorption by Sawdust | Safranine O Dye | Industrial Wastewater | (Saroha and Ghosh 2020; Abudi 2018; Familusi et al. 2018) |
Biosorption using Arachis Hypogaea | Safranin-O Dye | Textiles Industries | (Panchal and Ghosh 2020) |
Anaerobic digestion | Manure-borne pathogens | Agricultural waste | (Alegbeleye and Sant’Ana 2020) |
Sewage Sludge-Based Activated Carbon Adsorption | Phenolic Compounds | Industrial wastewater effluent | (Mu’azu et al. 2017) |
Blue-green walls | Nutrients such as Nitrates | Agricultural pollution | (Deletic and Wang 2019) |
Groundwater Recharge | Arsenic | Irrigation fields | (Sanyal et al. 2020) |
Modified magnetic resins (NDMP resin) | Ammonia Nitrogen | Industrial and municipal effluent | (Huang et al. 2018) |
Artificial aquifer research | Micropollutants | Municipal sewage | (Lazarova et al. 2011) |
Transition metal sulfides (TMSs) | Refractory organic pollutants | Industrial wastewater | (Li et al. 2021) |
Atomic layer deposition | Aquatic contaminants | Agricultural fields | (Huang et al. 2021; Li et al., 2021) |
Membrane bioreactors (MBRs) | | Industrial and Agricultre | (Meng et al. 2017) |
Sonication | Cyanobacteria (blue-green algae) | nutrients | (Rajasekhar et al. 2012) |
Green Liver System | Cyanotoxins | wastewater from aquaculture | (Serrà et al. 2021a) |
Floc and Sink | Cyanobacteria | | (Arruda et al. 2021) |
Lanthanum modified bentonite (LMB—‘Sink/Lock) | Planktothrix rubescen | | (Lürling 2020) |
Visible-LED Irradiation | Microcystin | River pollution | (Benamara et al. 2021) |
Hydrogen Peroxide approach | Cyanobacteria | Farmlands | (Lusty and Gobler 2021) |
Phosphorus elimination plant (PEP) combined with advanced pharmaceutical treatment | Phosphorus | Pharmaceutical | (Schimmelpfennig et al. 2012) |
Metal-organic frameworks (MOFs) | | | (Wang et al. 2019; Wang et al. 2019) |
Constructed wetland | Total nitrogen (TN) and total phosphorous (TP) | Industrial and domestic sewage | (Zhang et al. 2012) |
Graphitic carbon nitride-based membrane | | | (Cui et al. 2021) |
Single-atom catalysts (SACs) | | | (Huang et al. 2021) |
Fabric-based material | Oil spill | Oil refinery industry | (Wang et al. 2015) |
Water hyacinth (Eichhornia crassipes) for Phytoremediation | Sulfadiazine pollutant | | (Madikizel 2021) |
Eco-Remediation Technology | Heavy Metal | Industrial waste | (Rathoure 2019) |
Aquatic Vegetation Restoration Technology | | | (Sean et al. 2017; Geist and Hawkins 2016) |
Bio-Manipulation Technology | | | (Desai et al. 2007) |
Floating Aquatic-Plant Bed Systems | | | (Kırım et al. 2014; Deng and Ni 2013; Li et al. 2010) |
Wetlands Rehabilitation Technology | | | (Wang et al. 2020) |
Adsorption Technology | | | (Sivamani and Leena 2009; Eniola et al. 2019; Qu and Fan 2010) |
Advanced technology and strategies
Most advanced technologies for water pollution control identified throughout the review process are as follows (See Table 2): Electrodialysis to remove arsenic from water (Singh et al. 2009), atomic layer deposition (ALD) for aquatic remediation (Li et al. 2021), UV/H2O2 treatment (Sorlini et al 2020), Hydrogen peroxide for cyanobacteria removal (Lusty and Gobler 2021), Seaweeds as a source of the bioactive compound for cyanobacteria (Zerrifi at al 2020), Safranine O Dye removal by sawdust, dye removal by arnchis hypogaca (Panchal and Ghosh, 2020; Saroha and Ghosh 2020), pyrolysis treatment for bioenergy (Huang et al. 2020), water hyacinth (Madikizela 2021), phosphorus elimination plant (Schimmelpfennig et al. 2012), graphic carbon nitrite (Cui et al. 2021), bio-manipulation and adsorption technology (Desai et al. 2007), modified clay (Floc and Sink) (Arruda et al. 2021), carbon absorption(Qu and Fan 2010), aquatic vegetation restoration, metal sulfides base advanced oxidation process (Wang et al. 2019), bio-remediation (Rathoure 2019). The two strategies included ‘333’ integrated approach in china (Huang et al. 2018) and wetland construction (Zhang et al. 2012).
Over the years, industrial effluents have continuously damaged scarce water resources, making them unhealthy. This has become very difficult to manage since industries increase waste generation. The best solution to this problem, as proposed by researchers, is the development of technologies to reduce or eliminate waste from industries (Deletic & Wang, 2019). For example, after several policies have failed to improve the water quality of rivers in China, they invested in developing new advanced technologies for industrial wastewater treatment (Ni 2016; Wang and Song 2020). To reduce the amount of phosphorus discharge from pharmaceuticals into rivers in Belin, a phosphorus elimination plant was constructed to treat the effluent (Schimmelpfennig et al. 2012).
Policies Related To Industrial Pollution Prevention
Most important policies enacted in different countries with regards to industrial pollution prevention and control are as follow: Comprehensive control of pollutants discharge (Zhou et al. 2021), clean water act in USA (Keiser et al. 2019), Integrated Water Resource management (IWRM) for river basins in China (Huang et al. 2016), river basin water quality ( Wang & Song 2020), trading of nutrient pollution rights (Rahman 2014), pollutant discharge elimination system permit for industries in USA (Loar et al. 2011), environmental protection and management (Trade Effluent) regulations in Singapore for industrial discharge (Keiser et al. 2019), IWRM for Upper Comoe´ River Basin in Burkina Faso (Keiser et al. 2019), reduce pollution load effluent in Japan (Ministry of Environment 2011), the South Saskatchewan Water Management Plan (O’Grady 2008), regulatory control of sewage pollution from wastewater treatment plants in Malaysia (Ariffin and Sulaiman 2015), National Environment Policy in Pakistan for regulating industrial effluent discharge among others (EPD-HK 2007).
Contamination of natural water bodies by industrial pollution has become a big problem in Asia, Africa and Europe. Nearby communities and industrial operations frequently contaminate the main drinking water sources and inland water bodies. This has resulted in stiffer policies, regulations to control industrial waste. For example, several success stories have been recorded from the city of Chouhu in China after Chief Policy for water pollution control was implemented (Xu et al. 2020); however Ni (2016) disagrees because findings from his research indicated poor implementation of water policies in China.
Policies Related To Agricultural Pollution Control
Agriculture-related water pollution has immediate negative health consequences, such as the well-known blue-baby syndrome. In infants, excessive nitrate levels in water cause methemoglobinemia – a potentially fatal condition. Certain broad-spectrum and persistent pesticides (DDT and many organophosphates) were widely banned due to pesticide accumulation in water and the food chain. However, other pesticides are still used in impoverished nations, producing acute and possibly chronic health impacts (Mateo-Sagasta et al. 2017).
The most important policies implemented by different countries to curb water pollution are as follow EU water framework directive in Sweden regulating nitrates and phosphorus discharge from the agricultural field (Söderberg 2016), Total phosphorus standard developed for Cherry Creek in the USA (Rahman 2014), Nutrient Reduction Strategy (INRS) to reduce total nitrogen and phosphorous loads by 45% by 2035 (Rundhaug et al. 2018), Damodar Valley Corporation Prevention of Water Pollution Act. This act is found under India Water Policy to regulate the use of harmful agricultural pesticides and also gives permission for water withdrawals for agriculture (Pandey 2017); EU’s Common Agricultural Policy (CAP) in Germany specifies criteria to control the amount of nitrates in groundwater from agriculture (Law 2022). In June 2018, the European Court of Justice condemned Germany due to its failure to reduce groundwater pollution from nitrates (Environment Agency Section 2018). This could mean that the policies for regulating groundwater pollution were poorly implemented. On the other hand, it shows how the EU is strict in compelling all member countries to adhere to pollution control policies.
Prescriptive Policies
This approach is also known as the ‘Command-and-Control’ approach. It regulates the behaviour of factories and individuals using water resources. The approach comprises two classes; technology standards and performance standards (Eskeland and Jimenez 2019). Prescriptive policies identified in this review are as follow Action plan for water pollution and prevention in China (State Council of the People’s Republic of China 2015), the policy sets targets for water pollution control reduction, and appropriate approaches to achieve the set targets. It also requires factories to install certain pollution abatement technologies. For example, paper and pulp factories in China are directed to switch to total chlorine-free bleaching technologies. Wastewater reuse (Huang et al. 2016) is another government policy in China with a target of establishing sewage treatment plants for 95% of their cities and 85% of their villages by 2020 (Eskeland and Jimenez 2019). 11th Five-Year Plan for Water Resources Development (Jiang 2009) is another ‘command-and-Control’ approach to control river pollution in China (Jiang 2009). EU Water Framework Directive (WFD) uses approaches different from the water pollution control policies in China and USA. Unlike technology-specific policies, it mandates member states set coordinated but self-selected targets to improve water quality and control pollution. According to Eskeland and Jimenez (2019), it is possible to estimate the policy's benefits, but no known study is yet. Söderberg (2016) revealed in his study that Sweden could not meet their 2015 ecological goals for water due to incoherent policies and power struggles between authorities. USA Clean Water Act (CWA) is another prescriptive policy identified in the study. CWA is a set of effluent standards implemented through point-source permitting. It also requires point sources of pollution to achieve emissions limits based on “best available” technology, including a single technology or a small number of related technologies. The National Pollutant Discharge Elimination System (NPDES) is an example that specifies quantitative effluent limits by water pollutants for each point source with regards to the available technology. Many studies have indicated high compliance with the point source permits; this resulted in a dramatic increase in municipal sewage treatment. However, Keiser and Shapiro (2019) holds a different view that suggests a small positive impact, on average, on US waterbodies. Nutrient reduction strategy was enacted in Iowa State to regulate phosphorus pollution from agriculture. Certain conservation practices were adopted to reduce non-source point pollution (Rahman 2014). Also, India’s National River Conservation Plan (NRCP) is another regulation identified in this review (Nallathiga 2008). It has established a set of designated surface water uses with prescribed strategies for achieving water quality appropriate to those specified uses. This regulation defines the construction of municipal sewage plants. Still, it has no dedicated funding source, unlike the U.S.A CWA. Greenstone and Hanna (2014) revealed in their study that the NRCP has not reduced water pollution concentrations in rivers within the plan’s implementation areas. In their bit to control water pollution, Singapore implemented certain policies identified in this study are; Sewage and Drainage Act (SDA) and Sewerage and Drainage (Surface Water Drainage) Regulations. They are made up of stipulated control requirements for the proper discharge of surface-run off into stormwater drainage (Luan 2010). Total Pollutant Load Control System (TPLCS) is a regulation that focuses on source measures to control water pollution in Japan (Ministry of Environment 2011). This policy aims to reduce the amount of pollutant load from sources and purification the environment within water areas. Environmental Pollution Control Proclamation and Ethiopian Water Sector Policy are also examples of prescriptive policies. These policies focus on the river basin as the fundamental planning unit for controlling water pollution. It gives directions for establishing basin institutions for integrated management of water resources (Awoke et al. 2016). However, these institutions lack scientific tools considered essential for effective monitoring, preventing and controlling of water pollution (IRC 2019). Water pollution control in South Africa is regulated by the National Water Act 36 of 1998 (Nkosi and Odeku 2014). The primary objective of this act is to prevent the degradation of water resources. Section 19 of the act stipulates that any person, organisation, or owner of land whose activities have caused or are likely to cause water resource pollution should put up measures to stop or prevent it from happening (Rangata and Odeku 2014). Finally, the Water Management Act in Germany requires the sustainable management of water bodies. Water use, such as its withdrawal or discharge, requires a permit. Noncompliance may result in the withdrawal of permits by the authorities. For example, a farmer was made to pay for reclamation of private surface water for polluting with fertiliser.
Market-Based Policies
The set of market-based approaches are payments for watershed services, taxes and tradable permits, other market-based approaches exist, though they are outside the scope of this review (Eskeland and Jimenez 2019). Glachant (2002) observed in his study that such polices focus on raising revenue and not to abate pollution, targets are set so low that they cannot have any effect on pollution control. Such policies identified in this review are as follows: Salt Pollution Trading in Australia is an example of tradable permits controlling salt discharge into the Hunter River from sources such as brine disposal from coal mining, water diversions for cooling in electricity generation and irrigation return flow. Facilities are allocated with salinity credit and if they exhaust their credit, they can purchase from other facilities (Deletic and Wang 2019). Another market-based policy identified in the study is Transfer Payment of Ecological Functional Areas Policy (TPEFAP) in China. With this policy, counties prevent industrial development at national key ecological functional areas. In return, they receive transfer payment from the central government for the purposes of compensation. This payment compensate for restricting industrial development and cost incur for ecological protection (Pan and Tang 2021). Finally, Phosphorous Trading in the South Nation River Watershed, is another tradable permit identified in this review. Point source dischargers are bought phosphorus credits from rural landowners, primarily farmers. These credits are generated by constructing non-point source pollution control measures (O’Grady 2008).