2017
DOI: 10.1007/s12665-017-6561-5
|View full text |Cite
|
Sign up to set email alerts
|

In-well time-of-travel approach to evaluate optimal purge duration during low-flow sampling of monitoring wells

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
1
1
1
1

Citation Types

1
20
0

Year Published

2018
2018
2024
2024

Publication Types

Select...
4
2

Relationship

2
4

Authors

Journals

citations
Cited by 10 publications
(21 citation statements)
references
References 16 publications
1
20
0
Order By: Relevance
“…A common assumption for low-flow groundwater sampling was that low purge rates capture primarily lateral inflow (horizontal laminar flow) through the screened interval from the formation at depths coincident with the pump intake (Stone, 1997). However, because even low-flow sampling causes some drawdown in the well, convergent, in-well, vertical flow is induced toward the pump intake from inflow across the entire well screen (Harte, 2017). Varljen and others (2006) show that the entire well screen is sampled during low flow with preferential sampling of high permeability layers under steady-state transport.…”
Section: Low-flow Purgementioning
confidence: 99%
See 1 more Smart Citation
“…A common assumption for low-flow groundwater sampling was that low purge rates capture primarily lateral inflow (horizontal laminar flow) through the screened interval from the formation at depths coincident with the pump intake (Stone, 1997). However, because even low-flow sampling causes some drawdown in the well, convergent, in-well, vertical flow is induced toward the pump intake from inflow across the entire well screen (Harte, 2017). Varljen and others (2006) show that the entire well screen is sampled during low flow with preferential sampling of high permeability layers under steady-state transport.…”
Section: Low-flow Purgementioning
confidence: 99%
“…Inherent in many active/purge sampling methods (volumetric and low-flow) is the requirement that, prior to collecting a sample, field physical and chemical characteristics such as pH, DO, SC, temperature, and turbidity achieve some degree of stability as an indicator of formation water recharging the well water. Harte (2017) found that stabilization of field physical and chemical characteristics monitored during purging was useful in diagnosing the contribution of in-well vertical flow and transport to the pump intake location. However, stabilization of field physical and chemical characteristics during purging may not always be a reliable indicator of the chemical stability for other chemical constituents.…”
Section: Field Physical and Chemical Characteristics Stabilizationmentioning
confidence: 99%
“…The Q H from the Dupuit-Theim equation is calculated within the associated M z using K avg and compared against the Q p' to assess if Q v outside M z can take place. A "NO" is shown in cells B15:C16 of the "Input" worksheet when it is unlikely that Q v in the well is dominant, as discussed in Harte (2017). Note that if the P L is in the casing, Q v is assured.…”
Section: Forward Modementioning
confidence: 99%
“…Transient storage effects may be significant in cases where the drawdown (s) takes significant time to stabilize, in which case the analysis will overestimate values of K avg . The impact of formation S on K avg was evaluated by comparing the calculated K avg from the Theis equation, which accounts for aquifer storage, to the calculated K avg from the Dupuit-Theim equation as used by this analytical model (Harte, 2017). For a 1-ft drawdown or less, the effect of S for values of < 0.001 results in a small error (approximately a factor-of-2 difference) in the K avg calculated with this model.…”
Section: Assumptions and Limitationsmentioning
confidence: 99%
See 1 more Smart Citation