Artificial recharge systems applied in the Low Llobregat aquifers (Barcelona, Spain)

Transcription

1 Artificial recharge systems applied in the Low Llobregat aquifers (Barcelona, Spain) Jordi Martín-Alonso Water Quality Manager Aigües de Barcelona ISMAR9 Mexico DF, June 2016

2 Drinking Water Production in the Barcelona s Metropolitan Area Llobregat river intake in the DWTP (1999 and 2000) Total inhabitants = 3,2 milion Total drinking water from Llobregat river = 175 Hm3/yr DWTP Sant Joan Despí nominal capacity = 5.3 m 3 /s

3 Llobregat river resources Because of quality s variability of surface water used for drinking water production, the Sant Joan Despí Plant is really complex and control is not easy

4 The aquifer of the Llobregat s River delta and recharge strategy FREE AQUIFER CONFINED AQUIFER WTP Pumping area Martorell Castellbisbal Santa Andreu de la Barca Molins de Rei INDUCED Pallejá RIVERBED Sant Feliu de Llobregat RECHARGE Sant Joan Despí Cornella de Llobregat Sant Vicenç DEEP RECHARGE Surface: 110 km 2 Capacity: 114 hm 3 Length free aquifer: 11 Km Minimum width free aquifer: 0,25 Km Maximum width free aquifer: 2,1 Km Length confined aquifer: 9 Km Maximum width confined aquifer: 17 Km Operations Number of wells Capacity Extraction 31 4 m 3 /s Recharge 10 0,8 m 3 /s

5 Hydraulic balances

6 Hydraulic balance

7 Piezometric level deep aquifer

8 MAR systems in the Low Llobregat

9 Hydraulic sea intrusion barrier Injection of reclaimed wastewater, partially osmotized Well points close to hydraulic barrier. In white background the operational period. Cost 0,28 /m 3

10 Castellbisbal (a) and Sant Vicenç dels Horts (b) recharge ponds (a) (b) Total recharge capacity: 1,3 Hm/y 3-5 M construction budget

11 Scarification of the riverbed

12 Deep recharge with drinking water Recharge pipe

13 The system is limited as it is bydirectional 13 reversible wells Start date: 1969 Total capacity: m 3 /d Recharged volume range (90 s) 5 15 Mm 3 /year

14 Project of a new recharge pond m 2 of infiltration surface, two sources: river and reclaimed water Estimated construction budget: 8 M

15 Main characteristics of different MAR methodologies Characteristics Scarification Castellbisbal St Vicenç Pond Horts Pond ASR Hydraulic Barrier Availability of Water 15% >90% >90% 30 % >90% Chemical impact low low low low high Volume annual objective (0-14) 5.5 Quantity impact medium low medium Medium- high high Cost ( /m 3 ) There will be a deficit even in the more optimistic scenario

16 Current role of MAR (a) period (b) period

17 A view forward Despite all these systems and projects, in 2015 artificial recharge accounted for less than 0.5 hm 3 overall. And we still struggle treating surface water!! An attempt to revamp our current situation - The Sant Joan Despí Waterworks produces ~180 Hm3/y of drinking water, being most of it of surface origin - The quality of surface water is very variable and sometimes doesn t meet the minimum requirements for potabilization, then groundwater fully replaces surface water - The existing deep recharge infrastructure is relatively small and cannot be used if groundwater is pumped out

18 Riverbank filtration Sand filtered surface water Bank filtered groundwater Deep recharge of sand filtered water: the aquifer as a storage + improvement + stabilization of water quality

19 Dual system concept: deep recharge + pumping Recharge of water from the pre-treatment Pumping the recharged groundwater for continuing the treatment process

20 A view forward Advantages of this proposal - Surface water could be treated beyond current limits of quality, better use of scarce water resources - Stabilization of the quality of water in the advanced treatment (GAC, UF-RO) - High removal expected for Organic Matter treated water more stable at lower cost - Avoiding temperature changes, less breaks in the network - Green and sustainable solution I m looking forward to exchange experiences during ISMAR9 and beyond!

21 Títol MUCHAS GRACIAS POR SU ATENCIÓN THANK YOU VERY MUCH FOR YOUR ATTENTION