The first reported MAR site in Europe was in Glasgow (UK) where in the year 1810 the Glasgow Waterworks Company constructed a perforated collector pipe parallel to the Clyde River (Ray et al.
2002) and abstracted bank filtrated water (BMI
1985; note this site is not shown in Fig.
1 because it seems to be historically isolated). This method was successful at the beginning and many other cities in the UK (e.g., Nottingham, Perth, Derby, Newark; Ray et al.
2002) adopted the idea; thus, the 1860s became the first heyday of “naturally filtered water” in the UK (BMI
1985). However, many of these early sites experienced problems with decreasing well performance and had to be abandoned in later years (BMI
1985); nevertheless, the idea of “naturally filtered underground water” was born and spread to continental Europe, where it was soon adopted by cities in the Netherlands, Belgium, Sweden, France, Austria and Germany. The scientific investigation of “artificial underground water” in Europe began with the water engineers Dupuy, Belgrand, Salbach, Thiem and Richert in the late 19th century (Richert
1900). The progressing industrialization in the 19th century and growing population in European cities presented the water suppliers with new challenges. The traditional water supply based on surface water was impaired by increasing contamination from the new industries and improper sanitation. At that time, based on the experiences in the UK, Thiem proposed the application of riverbank filtration to cope with degrading hygienic surface-water quality and increasing water demand; thus, the pioneers of MAR in Germany can be found at the industrialization hubs close to the Rhine River (e.g., Water Works Düsseldorf 1870), the Ruhr River (e.g., WW Essen 1875), the Elbe River (e.g., WW Saloppe 1875, WW Hosterwitz 1908) around Dresden, and in the Berlin area (e.g., WW Müggelsee, switched to groundwater in 1904–1909, WW Tegel 1901–1903). To increase the abstracted water quantity, many water works constructed infiltration ponds which were often situated on the land side of the abstraction well galleries. Similar to the development in Germany, riverbank filtration (RBF) and infiltration ponds found application in the Netherlands, Sweden and Switzerland—for example, in the Netherlands, the first known RBF-based water supply was reported to have started its operation in 1890 (Stuyfzand
1989). The first MAR site in Switzerland started its operation in Basel “Langen Erlen” in 1912. Eastern European cities then followed and in Hungary the first RBF site was installed north of Budapest on a Danube island (Szentendre Island) in the 1920s (Homonnay
2002); to date, this MAR system is the main drinking water source for Budapest (Homonnay
2002). Additional RBF sites have been developed on other Danube islands (e.g., Csepel) and nowadays several RBF sites exist along the rivers of Raba, Drava, Ipoly, Sajo and Hernad (Homonnay
2002). In Romania the MAR history starts with the operation of the Iasi water supply system at the Moldova River in 1911 and the cities of Cluj Napoca followed in 1935 with conjunctive use of RBF and infiltration ponds and Bacau in 1961 (Rojanschi et al.
2002). In Finland the first water plant using groundwater replenishment by infiltration ponds started its operation in 1929 in Vaasa (Tapio et al.
2006). A few other plants were developed before and after World War II, but the systematic development of MAR in Finland started in the 1960s (Tapio et al.
2006). It is reported that in the year 1992 about 20 water suppliers relied on different MAR types mainly constructed in the 1970s and by 2002, already 25 operating water works utilized MAR in Finland (Tapio et al.
2006). Finally, Tapio et al. (
2006) report that after several decades of experience with MAR, this technique is continuously favored by water suppliers.
Research and development of well injection methods began in the 1960s. These early sites were mostly situated in the Netherlands where pilot-scale trials began. Stuyfzand et al. (
2012) report that many of these early ASR sites have been closed due to clogging problems. An exception is located in Barcelona, Spain, where a dozen ASR wells were constructed in the early 1970s and are still active today (Hernández et al. 2011). Here, the high transmissivity of the target aquifer (up to 40,000 m
2/day) and low turbidity (<1 NTU) of source water are key parameters associated with the good long-term system performance (Hernández et al.
2015). Cleaning cycles consist of pumping episodes of 15 days with a flow rate four times higher than the injection flow (Azcon and Dolz
1978). Maintenance strategies and clogging aspects are known to be important to consider for MAR practices, but were only rarely reported in the available literature for the European sites. However, in addition to turbidity, as illustrated by the example given, redox mixing and clay swelling are some of the additional factors to consider with respect to clogging risks, which may require pre-treatment prior to injection.
Until today, the expression “artificial recharge” has often been used. In Europe, this term dates back to the early investigators such as Richert (
1900) and describes “underground” water recharged by human activities. Later on in the late 1990s and the beginning of the 21st century the term ‘managed aquifer recharge’ was introduced. Some authors reason that “artificial recharge” falsely implies that a somewhat artificial process occurs (Dillon
2005), which can be misleading because the purification in the subsurface relies on natural processes. Moreover, the term MAR refers to the management of aquifer recharge, which implies that risks are managed in a quantitative way.