Dr. Enrique Fernández Escalante1, Jose David Henao Casas2, Dr. Ana María Vidal Medeiros3, Dr. Jon San Sebastián Sauto4
1. IAH MAR Commission, Tragsa R&D
2. Tragsa Group & Technical university of Madrid
3. WB consulter, Uruguay
4. Tragsatec
(a) Purpose or objectives and status of study or research hypothesis
The existing policies concerning Managed Aquifer Recharge (MAR), as a general rule, pay more attention on quantity, permissions and procedural aspects, than in the water quality standards and Maximum Allowable Concentrations (MACs).
Early-MAR countries usually adopt the WHO guidelines when developing new MAR activities, what, in certain cases, jeopardizes water resources.
The compilation and critical comparison of the already existing regulations which consider water quality characteristics for MAR and SAT-MAR, can become a Decision Support System (DSS) willing to provide modern concepts and guidelines for decision makers.
The analysis of 18 international regulations on MAR has been addressed, with important procedural and pragmatic outcomes.
(b) Key issue(s) or problem(s) addressed
The review and analysis of the existing regulations and guidelines can help improve the current policies regarding MAR. Such improvement entails the identification of weaknesses and strengths and the provision of suggestions for future binding regulations. The analysis must be performed in the face of a wide variety of factors, including economic, environmental, technical and scientific ones.
(c) Methodology or approach used
The IAH MAR Commission Forum was used as a communication channel to gather the existing regulations on MAR with important water quality issues. This task begun in 2014, and since then, different inputs have been aggregated into a data-base.
The recent publication of the water reuse European Regulation has prompted the comparison of all the existing world-wide regulations, the classification of good and bad, hard and soft, etc. aspects, so as to provide to decision makers some new elements to base their pronouncements. It is also an important mean for governance principles.
The canals used to provide inputs for regulators have been the public information period, the claim period and communications with the Common Implementation Strategy Group (a consultant group to provide scientific base to legislative resolutions).
(d) Results and conclusions derived from the project
Some important lessons and recommendations have derived from the analysis of 18 different regulations, guidelines and operator rules, proceeding from the five continents. For example: the necessary distinction to be made depending on the type of recharge, either direct injection, percolation, infiltration through ponds or wells, with different limits for each case; the methodological approach and recommendations to achieve a "monitored recharge"; tailor-made water quality guidelines based on aquifers and source water proposals; MAR sources and receiving medium considerations; developing a common terminology
recommendation; consensus for a permitting process; broader legal development; independent control and surveillance; inclusion of budgetary aspects on regulations; including the technical background for authorizations, study of the most frequently regulated parameters in the world up to date, the different considerations on emergent pollutants, etc.
(e) Implications of the project relevant to selected conference theme, theory and/or practice
The proposed paper sheds some light on the process to achieve a scientific-based regulation of water quality standards for MAR. Any adapted multi-barrier and multi-level approach should consider not only hydrogeochemical criteria, but all aspects of MAR techniques. Among these MAR features, the most remarkable are the water sources (e.g. treated wastewater, river water, rainwater, etc.); the MAR technologies (taking into consideration the soil and groundwater body, e.g. basin, flooding, well, etc.), and the final use of water (e.g. irrigation of cropland, drinking water, positive hydraulic barriers against sea water intrusion, etc.).
Summarizing, a series of recommendations are provided to help decision-makers in dealing with the complex task of formulating regulatory and operating frameworks entailing MAR.
It is worth to remark that the binding water quality standards should be designed “aquifer-wide”, considering the specific conditions of the water body and the sourced water, the aquifer purifying capacity, the recharging system, and the final use.
Additionally, concrete monitoring guidelines should be set, considering the cost of the analyses, the sampling frequency and the exact point/s to collect each aliquot.
Finally, a risk assessment approach should be part of the MAR policies.