SP-16 Groundwater Sampling
Targeted Water Samples
Using a Geoprobe screen point sampler enable water sampling from targeted points in the subsurface. With generic ground water monitoring wells, which often have screen lengths from 3-6m, any water samples recovered are inherently a composite of the full screened interval. Although helpful in understanding that a problem exists, it will not often provide detail that adds confidence or clarity around the coceptual site model. In many cases the generic approach to installation of monitoring wells allows contaminates present below the water table to penetrate other pathways present in the screened interval.
The completely sealed SP16 allows you to expose an internal screen as little as 10cm and providing water samples from a precise depth. The technique is very effectively used for calibration samples when undertaking site assessments with High Resolution Site Characterization (HRSC) tools.
Using direct push for discrete water sampling is fast. You can hit far more locations across a site than you would if you were having to construct and develop monitoring bores.
Minimisation of waste
Direct push groundwater sampling does has no derived waste. A standard solid auger well installation produces approximately 12L of soil per metre. Given the high clay content common in many Australian soils compaction is a problem and results in a 20-30% uplift of waste disposal volumes. The relentless increases in waste disposal costs means that using methods that minimise drilling derived waste are financially more competitive every day.
Most materials currently used for monitoring wells are unsustainable by nature, The environmental damage from mining raw materials, energy use in production and transport, and non-recyclable nature of the products are all concerning. Washed, graded and bagged Filter sand, PVC pipe shipped across the world and bagged, cement, and steel well covers, poly tubing for pumps, disposable bailers....the list goes on. Essentially the use of direct push screening and sampling minimises the use of all of these products appears at least on the surface to to be a more sustainable approach.
SP16 Sampling Methodology