Under/Above ground Storage Fuel Tank Management
EE&G offers under/above ground storage fuel tank Management. All comprehensive underground storage tank management services, ranging from assessment to closure and remediation. Ranging from assessment to closure and remediation. Storage tank management services offered by EE&G include:
- Tank inventory, priority ranking, and management planning
- Design and permitting of new or replacement tank systems
- Spill Prevention Control and Countermeasure (SPCC) plans
- Design of SPCC improvements and SPCC training
- Tank closure and environmental oversight
- Soil and groundwater assessment and remediation
EE&G can properly design and implement the closure or replacement of underground storage tank (UST) and fuel systems to comply with the upcoming 2009 compliance deadline. Additionally, EE&G has a Pollutant Storage System Specialty Contractor (PSSSC) as a designated subcontractor to properly permit, remove, and/or install both USTs and aboveground storage tanks (AST). While these storage tank upgrade issues can usually be planned and budgeted in advance, EE&G often identifies forgotten and/or improperly-abandoned USTs during routine Phase I and II ESAs, which require proper closure (abandonment-in-place or removal) within 90 days of discovery. Therefore, we are poised to provide an immediate response to these issues should they arise unexpectedly.
Groundwater Storage – Groundwater storage
Large amounts of water are stored in the ground. The water is still moving, possibly very slowly, and it is still part of the water cycle. Most of the water in the ground comes from precipitation that infiltrates downward from the land surface. The upper layer of the soil is the unsaturated zone, where water is present in varying amounts that change over time, but does not saturate the soil. Below this layer is the saturated zone, where all of the pores, cracks, and spaces between rock particles are saturated with water. The term groundwater is used to describe this area. Another term for groundwater is “aquifer,” although this term is usually used to describe water-bearing formations capable of yielding enough water to supply peoples’ uses. Aquifers are a huge storehouse of Earth’s water and people all over the world depend on groundwater in their daily lives.
Groundwater and Water Table
The top of the surface where groundwater occurs is called the water table. In the diagram, you can see how the ground below the water table is saturated with water (the saturated zone). Aquifers are replenished by the seepage of precipitation that falls on the land, but there are many geologic, meteorologic, topographic, and human factors that determine the extent and rate to which aquifers are refilled with water. Rocks have different porosity and permeability characteristics, which means that water does not move around the same way in all rocks. Thus, the characteristics of groundwater recharge vary all over the world.
In a way, this hole is like a dug well used to access groundwater, probably saline in this case. But, if this was freshwater, people could grab a bucket a supply themselves with the water they need to live their daily lives. You know that at the beach if you took a bucket and tried to empty this hole, it would refill immediately because the sand is so permeable that water flows easily through it, meaning our “well” is very “high-yielding” (too bad the water is saline). To access freshwater, people have to drill wells deep enough to tap into an aquifer. The well might have to be dozens or thousands of feet deep. But the concept is the same as our well at the beach—access the water in the saturated zone where the voids in the rock are full of water.
Pumping can affect the level of the water table
In an aquifer, the soil and rock are saturated with water. If the aquifer is shallow enough and permeable enough to allow water to move through it at a rapid enough rate, then people can drill wells into it and withdraw water. The level of the water table can naturally change over time due to changes in weather cycles and precipitation patterns, streamflow, and geologic changes, and even human-induced changes, such as the increase in impervious surfaces, such as roads and paved areas, on the landscape.
The pumping of wells can have a great deal of influence on water levels below ground, especially in the vicinity of the well, as this diagram shows. Depending on geologic and hydrologic conditions of the aquifer, the impact on the level of the water table can be short-lived or last for decades, and the water level can fall a small amount or many hundreds of feet. Excessive pumping can lower the water table so much that the wells no longer supply water—they can “go dry.”
Groundwater and global water distribution
Chart showing that 1.7% of Earth’s water is groundwater, 30% of Earth’s freshwater is groundwater, and 46% of Earth’s groundwater is freshwater. As these charts show, even though the amount of water locked up in groundwater is a small percentage of all of Earth’s water, it represents a large percentage of total freshwater on Earth. The pie chart shows that about 1.7 percent of all of Earth’s water is groundwater and about 30.1 percent of the freshwater on Earth occurs as groundwater. As the bar chart shows, about 5,614,000 cubic miles (mi3), or 23,400,000 cubic kilometers (km3), of groundwater, exist on Earth. About 54 percent is saline, with the remaining 2,526,000 mi3 (10,530,000 km3), about 46 percent, being freshwater.
Water in aquifers below the oceans is generally saline, while the water below the land surfaces (where freshwater, which fell as precipitation, infiltrates into the ground) is generally freshwater. There is a stable transition zone that separates saline water and freshwater below ground. It is fortunate for us that the relatively shallow aquifers that people tap with wells contain freshwater, since if we tried to irrigate corn fields with saline water I suspect the stalks would refuse to grow.