What is pump and treat remediation?
Pump and treat technology involves the retrieval of groundwater and/or NAPL from a contaminated aquifer using one or more extraction wells, trenches, or galleries, and treating the water in an above-ground treatment system prior to discharge.
How long does pump and treat take?
Pump-and-treat systems often take a very long time (e.g., 50 -100 years) to meet cleanup goals, and in many cases they are never expected to ever achieve those goals. Pumping depresses the groundwater level, leaving residuals sorbed to the soil.
Why does groundwater pumping and treatment take so long?
For example, it may take longer where: Contaminant concentrations are high, or the contamination source has not been completely removed. The contaminant plume is large. Groundwater flow is slow, or the flow path is complex.
What are remediation techniques?
Environmental remediation techniques include excavation, dredging, oxidation, soil vapor extraction, thermal desorption, pump and treat, nanoremediation, and more.
Why is pump and treat good?
Pump and treat systems also help keep the contaminant plume from spreading by pumping contaminated water toward the wells. This pumping helps prevent contaminants from reaching drinking water wells, wetlands, streams and other natural resources.
How does a pump and treat system work?
The contaminated groundwater is pumped and treated above ground before being disposed of or returned to the aquifer. The use of pump and treat technologies can help control the migration and spread of the contaminant plume.
What is the most common method for removing groundwater?
- Pump and treat is a common method for cleaning up groundwater contaminated with dissolved chemicals, including industrial solvents, metals, and fuel oil.
- In situ treatment occurs when groundwater is treated in place without extraction from the aquifer.
What is excessive groundwater pumping?
In this case, over pumping refers to a scenario where one takes so much water from the ground that the land shifts. The exact groundwater withdrawal value that is considered over pumping (and leads to subsidence) varies with each aquifer. The process that delivers arsenic into aquifers is slow and involves many parts.
What are examples 3 of types of remediation?
The main three types of environmental remediation and reclamation
- Soil remediation. There are many factors that affect the soil condition.
- Groundwater and Surface water remediation.
- Sediment remediation.
What are three site remediation methods?
Remediation methods, categorized as biological, chemical, or physical, are covered for contaminated soils and environmental waters.
Is pump and treat in situ?
Evolution of the in-situ process Pump and treat involves flushing clean water through contaminated zones, recovering the contaminated water, treating it in above ground reactors and re-infiltrating the treated water to enhance the removal of the more soluble contaminants.
Can you purify contaminated groundwater?
Pump and treat is a common method for cleaning up groundwater contaminated with dissolved chemicals, including industrial solvents, metals, and fuel oil. Groundwater is extracted and conveyed to an above-ground treatment system that removes the contaminants.
What are the uses of pump and treat systems?
Other uses of pump and treat systems include increasing the hydraulic gradient to improve contaminant recovery, recovery and reuse of an injectate, or groundwater recirculation to flush water through residual source areas or enhance the distribution of in situ treatment amendments (e.g., chemical oxidant or carbon substrate) in the subsurface.
When was the last time a pump and treat system was installed?
Pump and treat systems focused on contaminant mass reduction throughout a plume were widely installed in the 1980s and 1990s (NRC, 1994); however, performance data over the last several decades have shown that pump and treat technology is typically not an optimal choice for this purpose, except for rare sites (NRC, 1994; Navy RITS, 2018).
Why is the amount of contaminant recovered by pump and treat limited?
Because of the tendency of many contaminants to sorb to the heterogeneous soil types making up a typical aquifer, the contaminant mass recovered by a pump and treat system can quickly become limited by the slow pace of contaminant back-diffusion from soil into groundwater.
How can pump and treat reduce the footprint of plumes?
When applied to distal dilute, dissolved-phase plumes in permeable materials, pump and treat can effectively reduce the footprint of the plume. Significant contaminant mass reduction may also be achieved for more homogeneous and transmissive aquifer units (i.e., contaminant mass contacted by large number of pore volume flushes).