Horizontal Directional Drilling (HDD) can be used to insert a micro-porous pipeline under the ocean to draw seawater in for desalination. Testing is underway in Southern California to compare the water quality from a subsurface intake installed with HDD to the water quality from a conventional direct ocean intake. The subsurface intake constructed using HDD is based on a proven design developed by Catalana de Perforacions (Barcelona) with decades of operating experience along the Spanish Mediterranean coast. From shore, the boring materials can be removed to landfill. The specialized pipe can be assembled, floated from shore, towed to the site, and pulled back towards shore into the bore hole. The hypothesis is that the subsea intake will provide superior water quality for desalination (lower Total Organic Carbon, lower Dissolved Organic Carbon and lower Total Suspended Solids, lower microbial activity, lower concentration of biopolymers and polysaccharides). For the microporous pipe selected for the intake test program, the average grain size cut off is 60 μm resulting in a less complex pretreatment process, reduced energy and chemical use, and overall lower life-cycle costs for the desalination process.
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机译：水平定向钻井（HDD）可用于在海底插入微孔管道，以吸收海水进行淡化。南加州正在进行测试，以比较装有HDD的地下进水口与常规直接海洋进水口的水质。使用HDD构造的地下进气口基于Catalana de Perforacions（巴塞罗那）开发的经过验证的设计，在西班牙地中海沿岸拥有数十年的运营经验。可以从岸上将无聊的材料运往填埋场。可以组装专用管道，将其从岸上浮起，拖到现场，然后拉回岸上，钻入钻孔中。假设是，海底进水将为海水淡化提供优越的水质（较低的总有机碳，较低的溶解有机碳和较低的总悬浮固体，较低的微生物活性，较低的生物聚合物和多糖浓度）。对于选择用于进气测试程序的微孔管，平均截留粒度为60μm，这使得预处理过程更加简单，减少了能源和化学物质的使用，并降低了脱盐过程的总体生命周期成本。
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