Septic System Impacts on Source Water: Two Novel Field Tracer Experiments in Fractured Sedimentary Bedrock
Bibliographic record
Abstract
Septic systems are a common contributor of contaminants to groundwater that have implications for source water protection, particularly in fractured sedimentary bedrock environments. Two 24-h tracer experiments were performed that applied (1) the dye Lissamine Flavine FF and (2) three artificial sweeteners (acesulfame, sucralose, and cyclamate) in the leaching bed to examine solute transport from a single-family septic bed to a multilevel monitoring well installed in fractured sedimentary bedrock on a First Nation reserve in Southern Ontario, Canada. Tracer was first observed 3 h and 20 min after deployment, and breakthrough curves showed that multiple pathways likely exist between the septic bed and the monitoring well. Cyclamate concentrations were more elevated than expected compared to other studies that examined cyclamate’s attenuation in the laboratory and in porous media aquifers. Solute transport through the septic bed was analyzed with the numerical modeling software Hydrus 1D, which indicated that the septic bed may be too thin, located directly on bedrock, underlain by fractured soils, or bypassed through a short-circuit. The rapid transport of septic leachate to fractured sedimentary aquifers is problematic for First Nation and rural communities. More stringent regulations are needed for the design and use of septic systems in these environments.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".