TOEFL Integrated Writing Practice Test 012Salton Sea

The Salton Sea in California is actually a salty inland lake. The level of salt in the lake’s water—what scientists call its salinity—has been increasing steadily for years because the lake’s water is evaporating faster than it is being replaced by rainfall or rivers. If the trend continues, the lake’s water will soon become so salty that the lake will be unable to support fish and bird populations. The lake would then become essentially a dead zone. Fortunately, there are several ways to reverse the trend that is threatening the lake’s health.

First, one option is to directly remove salt from the lake’s water in special desalination facilities. These facilities would pump water from the lake, heat it to evaporate the water into steam, and leave salt behind. The steam would be cooled down and returned as salt-free water to gradually reduce salinity.

Second, another possible solution is to dilute the salt level by introducing ocean water. Since the Pacific Ocean is less salty than the lake, water could be piped or channeled into the lake to lower its salinity.

Third, constructing walls to divide the lake into sections is another proposed solution. In this plan, salinity would be allowed to increase in smaller sections, while the main section would be kept fresher by directing freshwater inflows to that part of the lake.