system and be of low cost

Because the discharge line for pipeline dredges is usually floated on top of the water, they are not suited to work in rough seas where lines can be broken apart or in high traffic areas where the discharge pipeline can be an obstruction to navigation. If there is a lot of debris in the dredging site, the pumps can clog and impair efficiency. The objective of capped in-water disposal would be to isolate contaminated material from the atmosphere by capping, or covering, the contaminated material with clean material ¡§C generally sand. The contaminated dredged material is placed on a level bottom or in deep pits or bottom depressions. Then clean material is dropped on leading. The cap is developed and meticulously place more than the contaminated sediment to make sure that it stays in location. Caps are developed to ensure that currents, waves, or the burrowing bottom creatures won't erode the protective layer more than time. Additionally, the caps are continually monitored to appear for indicators of failure.

Ocean Placement - Ocean Dredged Material Disposal Sites (ODMDS) are primarily used for material coming from inlets, coastal entrance bars, or main coastal navigation waterways. Typically, in ocean placement, a hopper dredge or towed barge sails to a designated area in the ocean, where the hull (bottom) of the vessel is opened. The dredged sediments drift to the bottom. Only clean dredged material may go to ocean sites. There are numerous types of dredges and methods for the removal of unwanted material within a waterway. Most recently the advent of the long stick excavator has allowed for mechanical removal. Numerous inexperienced individuals have entered into this line of work and unfortunately are not doing a very good job. It takes an exceptional operator to perform work that cannot be seen and most people attempting these projects are inexperienced at best.

.Today, modern dredgers use satellite information and computers to help dig channels. Until the 1970s, dredge captains used celestial navigation and markers placed on the riverbanks to guide their dredges. Now dredge captains use global positioning systems (GPS), which use satellite information to calculate the location of the dredge in the channel. On the dredge, information about the channel, the location of the shoal, and even the position of the dredge in the channel is likely to be displayed on a computer screen while they are working. Using computers to process and display information about the job and the dredge while they are working allows the dredging to be done with great efficiency. It saves time and money, and results in safer navigation channels. A solar irrigation system needs to take account of the fact that demand for irrigation water will vary throughout the year. Peak demand during the irrigation seasons is often more than twice the average demand. This means that solar pumps for irrigation are under-utilized for most of the year. Attention should be paid to the system of water distribution and application to the crops. The system should minimize water losses, without imposing significant additional head on the pumping system and be of low cost.

The technology:Water, Because it's so often hard to come by without the application of a considerable amount of electric power, those of us living off the power grid seem to have a preoccupation with it. Generally, we either carry water home from town in a big tank lashed into the bed of a one-ton pickup, use a fossil-fuel-guzzling generator to run a power-hungry AC (alternating current) well pump, or we simply beef up our solar arrays and improve our inverters to handle the load imposed by the ravenous well pump. Underwater excavation is called dredging. After the initial excavation needed to establish a channel, the periodic dredging that must be done to keep it clear and safe for navigation is called maintenance dredging. Once sediments are dredged from the waterway, they are called dredged material.People have been dredging channels in one way or another since primitive people began to irrigate crops. Until the early 1900s, dredges were crude and barely effective in keeping channels and harbors clean. Keeping the dredge in position in the channel, knowing how deep a channel was being dug, and even making accurate surveys of the completed channel, were a mixture of art and science. Experienced dredge captains and hydrographic surveyors (surveyors of the underwater topography) were able to produce remarkably good results, given the difficulty of their job.