Whenever desert soils (less than 10 inches of rain a year) are irrigated the water dissolves the salt, mineral and toxins and that water then leaches down into the groundwater. So your choices are: 1. Don't irrigate desert soils (less crop production). 2. Don't use the contaminated ground water (people then need another source of drinking water, and you have to make sure the water table never reaches the root zone). 3. Treat the contaminated ground water (cost lots of money). 4. Dump the contaminated ground water into the ocean (also cost lots of money). Or if you're really, , really, really "good" you can spin it as a public health problem that's not your fault and have the state taxpayers pay for it.