Interrelationships between biological, chemical, and physical processes as an analog to clogging in aquifer storage and recovery (ASR) wells

When evaluating uncertainties in developing an aquifer storage and recovery (ASR) system, under normal budgetary constraints, a systematic approach is needed to prioritise investigations. Three case studies where field trials have been undertaken, and clogging evaluated, reveal the changing perceptions of viability of ASR from a clogging perspective as a result of the progress of investigations. Two stormwater and one recycled water ASR investigations in siliceous aquifers are described that involved different strategies to evaluate the potential for clogging. This paper reviews these sites, as well as earlier case studies and information relating water quality, to clogging in column studies. Two novel theoretical concepts are introduced in the paper. Bayesian analysis is applied to demonstrate the increase in expected net benefit in developing a new ASR operation by undertaking clogging experiments (that have an assumed known reliability for predicting viability) for the injectant treatment options and aquifer material from the site. Results for an example situation demonstrate benefit cost ratios of experiments ranging from 1.5 to 6 and apply if decisions are based on experimental results whether success or failure are predicted. Additionally, a theoretical assessment of clogging rates characterised as acute and chronic is given, to explore their combined impact, for two operating parameters that define the onset of purging for recovery of reversible clogging and the onset of occasional advanced bore rehabilitation to address recovery of chronic clogging. These allow the assessment of net recharge and the proportion of water purged or redeveloped. Both analyses could inform economic decisions and help motivate an improved investigation methodology. It is expected that aquifer heterogeneity will result in differing injection rates among wells, so operational experience will ultimately be valuable in differentiating clogging behaviour under different aquifer conditions for the same water type. This paper was originally presented at ISMAR9, Mexico City 20-24 June 2016.

Section: Australian Field Research Data On Clogging Of Asr Wellsmentioning

confidence: 99%

Analysis of ASR Clogging Investigations at Three Australian ASR Sites in a Bayesian Context

Dillon

Vanderzalm

Page

et al. 2016

“…It is controlled by the river hydrology, the surface water quality, the well location with respect to discharge and distance from the riverbank as well as the characteristics of the riverbed [1,2]. Four types of clogging are known [3,4] and the name is given in accordance with its formation properties: physical (deposition, filtration of suspended solids), mechanical (gas entrapment), biological (bacterial growth) and chemical (precipitation reaction). The clogging process can be further specified, according its appearance, as external or internal clogging.…”

Section: Introductionmentioning

confidence: 99%

Riverbed Clogging and Sustainability of Riverbank Filtration

Grischek

Bartak

2016

Clogging refers to a reduction of riverbed hydraulic conductivity. Due to difficulties in determining the thickness of the clogging layer, the leakage coefficient (L) is introduced and used to quantify the recoverable portion of bank filtrate. L was determined at several riverbank filtration (RBF) sites in field tests and using an analytical solution. Results were compared with data from similar experiments in the early 1970s and 1991-1993. In the 1980s, severe river water pollution in conjunction with high water abstraction led to partly unsaturated conditions beneath the riverbed. A leakage coefficient L of 5 × 10 −7 s −1 was determined. After water quality improvement, L increased to 1-1.5 × 10 −6 s −1 . An alternative, cost and time efficient method is presented to estimate accurate leakage coefficients. The analytical solution is based on groundwater level monitoring data from observation wells next to the river, which can later feed into numerical models. The analytical approach was able to reflect long-term changes as well as seasonal variations. Recommendations for its application are given based on experience.

“…According to the investigation on 207 groundwater recharge systems in Maryland, USA, the rate of loss function system attributed to clogging increased to 50% in 1990 from 33% in 1986 [12]. Clogging is generally caused by inter-dependent mechanisms that are often hard to distinguish [13][14][15]. The classification of clogging into physical, chemical and biological processes is quite standard [16].…”

Section: Introductionmentioning

confidence: 99%

The Prediction Methods for Potential Suspended Solids Clogging Types during Managed Aquifer Recharge

Fang

Zi-jia

et al. 2014

Abstract:The implementation and development of managed aquifer recharge (MAR) have been limited by the clogging attributed to physical, chemical, and biological reactions. In application field of MAR, physical clogging is usually the dominant type. Although numerous studies on the physical clogging mechanism during MAR are available, studies on the more detailed suspended clogging types and its prediction methods still remain few. In this study, a series of column experiments were inducted to show the process of suspended solids clogging process. The suspended solids clogging was divided into three types of surface clogging, inner clogging and mixed clogging based on the different clogging characteristics. Surface clogging indicates that the suspended solids are intercepted by the medium surface when suspended solids grain diameter is larger than pore diameter of infiltration medium. Inner clogging indicates that the suspended solids particles could transport through the infiltration medium. Mixed clogging refers to the comprehensive performance of surface clogging and inner clogging. Each suspended solids clogging type has the different clogging position, different changing laws of hydraulic conductivity and different deposition profile of suspended solids. Based on the experiment data, the ratio of effective medium pore diameter (D p ) and median grain size of suspended solids (d 50 ) was proposed as the judgment index for suspended solids clogging types.