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MANAGED AQUIFER RECHARGE PROJECT FOR CHIHUAHUA, MEXICO
9th International Symposium on Managed Aquifer Recharge
Mexico CityJune 20 – 24, 2016
González Villarreal F., Cruickshank Villanueva C., Palma Nava A., Mendoza Mata A.
Overview of Recharge and Study Locations
Enhanced natural recharge
Infiltration from ponds
Aquifer storage recovery (ASR) Injection/recovery
Overview of Recharge and Study Locations
Chihuahua city
Chihuahua is the state capital of the Mexican state of Chihuahua.It has a population of about 925,970. The predominant activity is industry, including domestic heavy, light industries, consumer goods production, and to a smaller extent maquiladoras.There are 2 principals rivers: Chuvíscarand Sacramento.Anual average precipitation: 400 mm
Water balance in Chihuahua City
Water balance in Chihuahua city, (Mm3 / year)
Artificial recharge potential
TOTAL
DRAINAGE
Mm3/year
EFFLUENT
WWTP
Mm3/year
CONCESSIONED
VOLUME
Mm3/year
UNCONCESSIONED
VOLUME
Mm3/year
72
NORTE 13 7 reuse 6
SUR 54 35 irrigation 19
OTRAS 5 - 5
POTENTIAL: 30
Selection of Recharge Sites
SITE SELECTION PROTOCOL
1. Evaluate water supply needs
2. Identify potential sites
3. Identify pertinent factors
4. Decide importance weight of factors
5. Define actions necessary for proper evaluation of each pertinent factor
6. Arrange actions in order of the significance of the factor each action evaluates
7. Perform actions for each site to determine viability of artificial recharge
8. Is artificial recharge applicable to meet the needs of the area at this site(s)?
Selection of Recharge Sites
Double-ring infiltrometerexperiments
Surficial geology / soil surveysGeophysics – VES
Monitoring Recharge Operations
-Surface Ponds and Unsaturated-Zone Monitoring
Monitoring Wells
Unsaturated-ZoneMonitoring Site
?
?
?Time of Travel?
Geochemical Trasformations?
North WWTPSacramento river bathymetry and VES
Characterization of Recharge Sites
Overview of Recharge and Study Locations
Chihuahua city Waste Water Treatment Plant
Characterization of Recharge Sites
South WWTPVertical Electrical Sounding
Conceptual model
Alluvial
Gravel
Sand
Gravel
Silt
Treated wastewater
UnsaturatedZone
Pilot test
Infiltration lagoon
Percolation Flooding Dry Waiting
General aspects for design of pilot test
Type of aquifer Unconfined
Influent sourceTreated wastewater
(secondary level)
Saturated Khh 1 m/d
Flow rate 20 lps
Infiltration surface
100 m2
Dry/wettingcycles
5 days / 2 days
Auxiliarystructures
Pipes, valves and hydraulic structures for regulating
levels
Vadose zone depth
100 m
Monitoringwells
3
Operation – dry/wetting cycles
Instrumentation of monitoring wells (design and construction of borehole)
Instrumentation of monitoring sites
Unsaturated-Zone Monitoring Sites
MATRIC POTENTIAL
• Advanced tensiometers: measure matric potential andsaturated pressures between -800 to 800 cm (-0.8 to 0.8bars) and are usually installed near the water-table orabove clay layers or other materials where water mayaccumulate.
• Heat-dissipation probes: measure matric potential lessthan -70 cm (-0.07 bars) and are typically installed indrier materials.
• Dielectric permittivity sensors: measure matricpotential less than -100 cm (-1 bar) and are able tomonitor wetter materials than heat-dissipation probes.
WATER QUALITY DATA
• Suction-cup lysimeters: used to collect samples ofunsaturated-zone water.
Monitoring plan design
Monitoring wells plan design, according to NOM – 014 – CONAGUA – 2007
Site Normativity Period Duration
Effluent WWTPNOM-014-CONAGUA-2007
NOM-127-SSA1-1994 Biweekly 6 months
(minimum)
Near wellsNOM-127-SSA1-1994
NOM-014-CONAGUA-2007Unique sample Unique sample
Monitoring Wells(pilot test)
NOM-127-SSA1-1994NOM-014-CONAGUA-2007 Monthly
6 months(minimum)
• Source of water: Water of impairedquality (treated waste-water)
• Interactions between recharge waterand aquifer matrix
• Interactions between recharge andnative groundwater
• Interactions between recharge andconstructed well(physical clogging,precipitation of minerals)
Geochemical considerations
Vadose zone model – concentration of solute in the porous media
Conclusions
Quantitative understanding of the effects of aquifer heterogeneity on injection,
storage, and recovery is one of the most effective tools available to understand the
physical movement of recharge water and the mixing sorption and degradation
reactions that occur within aquifers and the unsaturated-zone that control the
movement, quality, and quantity of recovered water.
