WaterTech 2013

Jamie Wills (Waterline Resources Inc.) Jon Paul ‘JP’ Jones (AITF & U Waterloo)

What is GW-SW interaction? Why is it important? GW-SW interaction and oil sands How it is typically assessed? Where confusion arises

A hydraulic connection between subsurface water (groundwater, GW) and surface water (SW)

Water flow can be directed from: GW ’ SW (discharge) SW ’ GW (recharge) Both ways

Jyrkama (2003)

GW discharge to SW body. The opposite can also occur.

http://pubs.usgs.gov/circ/circ1139/htdocs/natural_processes_of_ground.htm

On the 3 figures compare the elevations of water table and river to resolve flow direction

GW-SW interaction a function of: Darcy Law (q = Ki)

Hydraulic head differences (i) Hydraulic conductivity (K)

Topographic lows (commonly GW discharge areas)

Topographic highs (common GW recharge areas)

Main GW-SW controlling factor = K

GW flow rates (v = Ki/porosity[n]) through typical Alberta clay till.

Assuming K = 1 x 10-8 m/s, n of 30%: GW flow rate (v) to SW body of ~1 cm/yr (assuming 1% hyd. grad.) v increases to ~10 cm/yr (assuming 10% hyd. grad.) Note: the flow rate is directly proportion to K of saturated medium, and

flow rates can be much higher in high K saturated media

GW recharge rate (infiltration of precipitation)

through typical Alta clay till: Commonly reported at ~2 % of precipitation Yields a GW recharge rate of 8 to 12 mm/yr (based on typical Alta.

precipitation range of approx. 400 to 600 mm/yr)

GW – SW interaction at oil sands projects: Often assumed that GW-SW interaction represents an important

component of the local hydrologic regime Assumption often invalid due to low K of subsurface media There are notable exceptions

Existing/planned mining and in-situ projects must assess it Condition of operating approval of existing oil sands projects Condition of TOR of new oil sands project applications GW-SW assessment reviewed at:

Local and stakeholder level Provincial level Federal level

How/where is it typically addressed in new oil sands project applications? Hydrogeology Baseline Report of EIA Hydrology Baseline Report of EIA

How is it (or could it) be addressed in the Hydrogeology Baseline Report? Qualitatively

Discuss based on lithology and expected flow regime Quantitatively

MWs, seepage meters, diffusion membrane samplers, etc Darcy-type calculations Chemistry (dissolved, stable and radioactive isotopes) Numerical modelling (changes in discharge rates to SW bodies)

Both may be used as GW-SW interaction = inexact science

It is crucial that all parties recognize this fact

How is it typically addressed in the hydrology baseline report? Qualitatively

Use of text consistent with the Hydrogeology Baseline Report Quantitatively (may or may not be completed)

Calculate a water balance for a given watershed or SW body The GW term is assumed to be equal to the difference (either +

or -) between input terms and output terms: Depending on + or -, infer whether GW is discharging into or

out of the SW body Method inaccurate due to uncertainty with accurately

quantifying main terms in water balance equation

Where confusion arises Lack of commun. between hydrogeologist and hydrologist Where reviewer’s expectation of the accuracy of the GW-SW

interaction predictions are not met Where predictive results are over sold

All of the above promote: Ongoing confusion Increased SIRs from regulatory bodies and stakeholders A prolonged approval process

All is not lost because smart people have sorted out managing uncertainty… Albert Einstein (1879-1955); Isaac Newton(1642 – 1727); William

of Ockham (1285–1349); Ptolemy (90-168); Aristotle (384-322)

They agreed that when you have competing theories that make exactly the same predictions, the simpler one is typically the better… “Pluralitas non est ponenda sine neccesitate”

We also have improved numerical modelling tools and approaches to help us resolve GW-SW interaction As detailed in Part 2 of presentation (JP Jones)”

An Improved Method to Assess Groundwater –

Surface Water Interaction in Oil Sands Projects: Part 2

Jamie Wills (Waterline Resources) Jon Paul ‘JP’ Jones (AITF & U Waterloo)

WaterTech 2013 Conference, Banff, AB, April 10-12

For all Modelling Work (in the Oil Sands or Anywhere else), One Should Always Strive Towards One Simple Goal…

Avoiding This Situation

Modeller

Regulators & Clients

SOCIALisBETTER Photostream Flickr.com CC BY 2.0

Bioxid’s Photostream Flickr.com

CC-BY-SA 2.0

Examples of Traditional Hydrological Modelling Tools

MODFLOW FEFLOW HSPF SWAT

These Are All Fine Tools When Applied

Competently Within Their Respective Domains But Results Can Be Considerably More

Uncertain When These Tools Are Applied To Situations They Were Not Meant For

Groundwater

Surface Water

The Hydrologic Cycle

Jyrkama 2003

• Many Common Models Treat GW & SW Hydro Regimes as “Nearly” Isolated Systems

• This Approach Has a Number of Severe Limitations

• Often Desirable to

Instead Think of the System as a Single, Interactive Resource

Possible Issues With Traditional Models Used In The Oil Sands

Key Hydrological Processes May be Missing or Overly Simplified

Discontinuities in Flow and Solute Transport Pathways Between Surface and Subsurface

User-Defined Parameterization of Processes Across

the Land Surface Interface (aka let “Physics” deal with this, not the modeller)

Lack of Dynamic Feedback

Large Number of Problems that Cannot be Addressed

with these Types of Models

Integrated Models

aka GW-SW Interaction Models aka Conjunctive Models

Able to address the Major Issues Associated with

Traditional Hydrological Models

Starting to be used in the Oil Sands and across Alberta BUT! Integrated Models are not a Panacea Like Traditional Models, they have their own

‘quirks’ Data availability/quality is an issue for all modelling

endeavors (as is predictive uncertainty) Steeper learning curves, user competency becomes

even more important

Examples of Integrated Models

HydroGeoSphere (AQUANTY)

MIKE SHE (DHI)

GS-FLOW (USGS)

MODHMS (HydroGeologic)

FEFLOW/MIKE 11 (DHI-WASY)

Jones et al (2006)

Closure

Thank you Questions?