Climate controls on nitrate concentration variability in the Abbotsford-Sumas aquifer, British Columbia, Canada

Graham, Gwyn; Allen, D. M.; Finkbeiner, Bernhard

doi:10.1007/s12665-014-3072-5

Cited by 6 publications

(12 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This follows suit with general conclusions that El Niño is associated with less precipitation and La Niña with more precipitation in southwest BC and the Pacific Northwest (Shabbar et al, 1997;Higgins et al, 2007;Fleming and Whitfield, 2010;Fleming and Quilty, 2006). Graham et al (2014) showed that precipitation, groundwater levels, and nitrate concentrations in the Abbotsford aquifer fluctuate cyclically (~5 years) and are likely associated with ENSO cycles or the PNA pattern. Both of these studies considered seasonal and annual variability in recharge, with no specific focus on heavy rain events.…”

Section: Heavy Rainfall and Climatesupporting

confidence: 88%

“…In the Abbotsford area of southwest BC, Fleming and Quilty (2006) established that groundwater levels tend to be higher during La Niña years and lower during El Niño years with the strongest correlation observed in the winter and spring. Graham et al (2014) showed that nitrate concentrations in the Abbotsford aquifer fluctuate cyclically (~5 years) and are likely associated with ENSO cycles or the PNA pattern. Groundwater recharge is therefore anticipated to be linked to the occurrence of heavy rain events, which may be associated with natural climate variability (ENSO, PDO, MJO, PE storms, or PNA) in the historic record.…”

Section: Enso Is Characterized By Fluctuating Sea Surface Temperaturementioning

confidence: 99%

See 1 more Smart Citation

Response of a fractured bedrock aquifer to recharge from heavy rainfall events

Rathay

Allen

Kirste

2018

Journal of Hydrology

View full text Add to dashboard Cite

The response of a fractured bedrock aquifer in a temperate region (Gulf Islands, British Columbia) to heavy rainfall events is characterized. Of the 14 provincial observation wells with hourly groundwater level data, wells with shallow water levels showed pronounced responses to heavy rain events, a lag less than 12 hours, and a strong correlation to all rain events. Rises in groundwater level at Well 125 appear to be better related to all rain events than exclusively heavy rain during summer, and decrease as the rainfall intensity increases. Thermal infrared images and δ 18 O and δ 2 H composition for precipitation and seepage indicate an increase in seepage in the late fall and winter.Solution of the Green-Ampt equation for rainfall events of varying magnitude suggest that an increase in winter rainfall intensity leads to more surface ponding and overland flow. The projected occurrence of more heavy rain events in the future may result in lower net recharge.

show abstract

Section: Heavy Rainfall and Climatesupporting

confidence: 88%

Section: Enso Is Characterized By Fluctuating Sea Surface Temperaturementioning

confidence: 99%

Response of a fractured bedrock aquifer to recharge from heavy rainfall events

Rathay

Allen

Kirste

2018

Journal of Hydrology

View full text Add to dashboard Cite

show abstract

“…Both wells sampled are completed in the upper 20 m of an unconsolidated gravel and coarse sand aquifer with discontinuous lenses of till and clay which continues to a depth of up to 60 m, underlain by a glaciomarine clay aquitard [ Cox and Kahle , ; Graham et al ., ]. The heterogeneous stratigraphy has produced complex, preferential flow paths, which can result in rapid transport of water and contaminants through the vadose zone (supporting information Figure S1) [ Scibek and Allen , ].…”

Section: Introductionmentioning

confidence: 99%

“…On a seasonal basis the water table can range as much as 4 m/yr in some wells [ Hii et al ., ]. Precipitation and recharge are maximized in the fall and winter leading to the highest water level at this point of the year, although there is often a delay of 1–3 months between peak precipitation and water level response [ Wassenaar et al ., ; Chesnaux and Allen , ; Graham et al ., ].…”

Section: Introductionmentioning

confidence: 99%

The atmospheric transport of iodine‐129 from Fukushima to British Columbia, Canada and its deposition and transport into groundwater

Herod

Suchy

Cornett

et al. 2015

Water Resources Research

View full text Add to dashboard Cite

The Fukushima-Daiichi nuclear accident (FDNA) released iodine-129 (15.7 million year half-life)and other fission product radionuclides into the environment in the spring and summer of 2011. 129 I is recognized as a useful tracer for the short-lived radiohazard 131 I, which has a mobile geochemical behavior with potential to contaminate water resources. To trace 129 I released by the FDNA reaching Canada, preaccident and post-accident rain samples collected in Vancouver, on Saturna Island and from the National Atmospheric Deposition Program in Washington State were measured. Groundwater from the AbbotsfordSumas Aquifer was sampled to determine the fate of 129 I that infiltrates below the root zone. Modeling of vadose zone transport was performed to constrain the travel time and retardation of 129 I. The mean preaccident 129 I concentration in rain was 31 3 10 6 atoms/L (n 5 4). Immediately following the FDNA, 129 I values increased to 211 3 10 6 atoms/L and quickly returned to near-background levels. However, pulses of elevated 129 I continued for several months. The increases in 129 I concentrations from both Vancouver and Saturna Island were synchronized, and occurred directly after the initial release from the FDNA. The 129 I in shallow ( 3 H/ 3 He age <1.4 years) Wassenaar et al. (2006) groundwater showed measurable variability through March 2013 with an average of 3.2 3 10 6 atoms/L (n 5 32) that was coincident with modeled travel times for Fukushima 129 I. The groundwater response and the modeling results suggest that 129 I was partially attenuated in soil, which is consistent with its geochemical behavior; however, we conclude that the measured variability may be due to Fukushima 129 I entering groundwater.

show abstract

“…Based on Environment and Climate Change Canada (ECCC) monitoring, the highest seasonal and temporal variations in NO − 3 are found in wells screened near the water table. Both seasonal and long-term temporal variations in groundwater-nitrate over decadal timeframes are well documented (Liebscher et al, 1992;Graham et al, 2015). The aquifer has little widespread intrinsic capacity to sustain microbial denitrification (self-remediation) because of largely aerobic conditions and the low organic content of the aquifer materials (Wassenaar, 1995), but it can occur in localized pockets around riparian discharge zones.…”

Section: Study Area and Hydrogeologic Settingmentioning

confidence: 99%

High-frequency NO3− isotope (δ15N, δ18O) patterns in groundwater recharge reveal that short-term changes in land use and precipitation influence nitrate contamination trends

Suchy

Wassenaar

Graham

et al. 2018

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Poultry manure is the primary cause of nitrate (NO3-) exceedances in the transboundary Abbotsford–Sumas aquifer (ASA; Canada–USA) based on synoptic surveys two decades apart, but questions remained about seasonal and spatial aspects of agricultural nitrate fluxes to the aquifer to help better focus remediation efforts. We conducted over 700 monthly δ15N and δ18O of nitrate assays, focusing on shallow groundwater (< 5 years old) over a 5-year period to gain new insight on spatio-temporal sources and controls of groundwater nitrate contamination. NO3- concentrations in these wells ranged from 1.3 to 99 mg N L−1 (n=1041) with a mean of 16.2±0.4 mg N L−1. The high-frequency 15N and 18O isotope data allowed us to identify three distinctive NO3- source patterns: (i) primarily from synthetic fertilizer, (ii) dynamic changes in nitrate due to changes in land use, and (iii) from a mix of poultry manure and fertilizer. A key finding was that the source(s) of nitrate in recharge could be quickly influenced by short-term near-field management practices and stochastic precipitation events, which ultimately impact long-term nitrate contamination trends. Overall, the isotope data affirmed a subtle decadal-scale shift in agricultural practices from manure increasingly towards fertilizer nitrate sources; nevertheless, poultry-derived N remains a predominant source of nitrate contamination. Because the aquifer does not generally support denitrification, remediation of the Abbotsford–Sumas aquifer is possible only if agricultural N sources are seriously curtailed, a difficult proposition due to longstanding high-value intensive poultry and raspberry and blueberry operations over the aquifer.

show abstract

Climate controls on nitrate concentration variability in the Abbotsford-Sumas aquifer, British Columbia, Canada

Cited by 6 publications

References 37 publications

Response of a fractured bedrock aquifer to recharge from heavy rainfall events

Response of a fractured bedrock aquifer to recharge from heavy rainfall events

The atmospheric transport of iodine‐129 from Fukushima to British Columbia, Canada and its deposition and transport into groundwater

High-frequency NO<sub>3</sub><sup>−</sup> isotope (<i>δ</i><sup>15</sup>N, <i>δ</i><sup>18</sup>O) patterns in groundwater recharge reveal that short-term changes in land use and precipitation influence nitrate contamination trends

Contact Info

Product

Resources

About