Method for constructing a synthetic infiltration collection system

Abstract

The present invention is method for constructing a synthetic infiltration collection system for installation at seaside locations. This system filters undesirable elements from seawater including detritus, suspended solids, garbage, debris, volatile organics, toxic and harmful algal blooms and other biologics. The resulting filtered seawater is then pumped to a desalination plant for de-salting. This system comprises a subterranean reservoir installed at a sheltered location, such as behind a set of dunes. A borehole is created by slant drilling, the borehole breaking through the surf line and into the open ocean. A pipe is laid in the bore hole, the pipe extending from the reservoir out to the open ocean. The pipe ends in an intake, which is overlapped by gravel packets which act as filtration media. The intake receives water filtered through the gravel packets, which is transported through the pipe to the reservoir.

Description

1. CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This patent application claims the benefit of U.S. provisional patent application Ser. No. 60 / 737,252, filed on Nov. 15, 2005.2. TECHNICAL FIELD [0002] This invention relates to the field of desalination of seawater and more specifically, to a method for constructing a filtered seawater collection system which removes suspended solids, debris and biological material prior to subjecting the seawater to desalination. 3. BACKGROUND [0003] Seawater desalination is becoming an attractive source of drinking water in coastal states as the costs for desalination decline. A prime consideration for seawater desalination is a source of feed water that is reliable and consistent to sustain operations and produce potable water effectively and efficiently. The amount and quality of feed water entering a desalination plant is greatly dependent upon the placement of the feed water intake. Up to the present time, feed water intakes have been of two b...

AI Technical Summary

Benefits of technology

[0011] The synthetic infiltration collection system, which is constructed by the inventive method, provides high quality water without being dependent upon local nearshore geological formations. The system also provides water volumes much higher than systems that depend upon indirect intakes that are dependent on nearshore geology. The system's ability to eliminate dependency upon local nearshore geology allows it to be placed in coastal areas of the world where the nearshore geology renders indirect intakes an impossibility. This dependency on local geology is eliminated primarily because the inventive method for constructing the system employs directional drilling techniques to place the intake pipe of the system. Directional drilling allows for drilling through the nearshore geology in any coastal location, so that the intake pipe can be placed in the open ocean.

[0012] The inventive method is comprised of placing a subterranean reservoir in communication with the first end of an intake pipe. The reservoir is buried at a level approximate to sea level so that the inflow of water from the intake pipe occurs until the water in the reservoir reaches sea level. Directional drilling methods are used to create a bore for the placement of an intake pipe. Directional drilling can be used to place a single intake pipe. Alternatively, directional drilling can be used to place a very large pipe, such as a pipe having a 30″ or greater bore diameter. The large pipe in this case acts as a bore lining so that a plurality of intake pipes can be placed inside of the large pipe and connected to the reservoir. This allows for the filtration of much higher volumes of seawater from the multiple intakes. Also, as desalination needs grow with population growth, this configuration would allow for more intake pipes to be added.

[0013] The intake pipe extends from the reservoir out past the nearshore and into the open ocean where it is preferably anchored to the sea floor. The opposite end of the pipe terminates at an intake area where the pipe is perforated with a plurality of openings. In one embodiment, geological materials, preferably gravel, are filled into porous containers resembling bed mattresses and enclosed therein. The containers are then lowered precisely upon the intake so that the porous containers cover the intake openings. The containers then act as a portable geology causing only filtered seawater to enter the pipe. Undesirable suspended elements such as detritus, suspended solids, other suspended biologics, debris and hydrocarbons are either greatly reduced or eliminated altogether by the system. The placement of the intake in the open ocean also allows for the system to produce volumes of water above that of prior art indirect intake designs.

[0016] Still another object of the invention is to provide an inventive method for constructing a system for filtering seawater, which allows desalination plants to be located in areas having undesirable nearshore geology.

Problems solved by technology

However a first drawback of direct intakes is that they are hampered by impingement and entertainment of planktonic organisms that require additional filtration and pretreatment once the seawater arrives at the plant, thereby driving up fresh water production costs.

Other common problems associated with direct intakes include biological fouling of intake pipes, trash and other debris in intakes, hydrocarbon products in feed water and recirculation of discharge to intakes.

Additionally, uncertain construction permitting outcomes related to direct intakes in light of modified regulatory practices derived from Section 316(b) of the Clean Water Act plague desalination plant developers.

However a drawback exists in that the water supply produced by a beach well is totally dependent on hydrogeologic conditions at the site.

Furthermore, in comparison to the unlimited seawater supply from direct intakes, beach wells typically provide water volumes in the range of only 400-4000 cubic meters per day.

However, like beach wells, they are limited by the nearshore geology.

Also, Ranney wells can be hampered by silt buildup and may also influence onshore groundwater resources, so careful evaluation of site characteristics must be employed before a Ranney well can be installed.

Further, the limitation in production capacity limits the use of indirect seawater intakes to only small desalination plants.

Also, due to the fact that indirect seawater intakes must be placed near the nearshore, they are vulnerable to storm damage or damage from beach erosion.

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