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Western States Water Council Water Quality Committee Sheridan, Wyoming October 5,2006 . as high quality as we would like to support irrigation, but there's a viable industry supported by irrigation in that valley and we feel it's very important to protect. In setting the standards, we looked at conductivity and salt, which has adverse impacts to crops. Too much salt kills the plant. We looked at the crops that were being grown in those valleys and interestingly enough, agriculture evolved around the water quality. In the Tongue River valley, people grow field beans. We decided we needed to protect the crop, so we set a lower standard. In the Powder River valley, it's closer to what's acceptable for alfalfa and com, so that's how we set the criteria. SAR absorption ratio looks at the relative portions ofthe sodium, calcium and magnesium in the water. If you get too much sodium in your soil, it causes dispersion. Basically, the soil itself tends to flow and run when it's wet, but sets up like concrete when it's dry. It doesn't support plant life and can be very expensive once it gets to that point. The people who live in the Powder River basin have learned how to take the good quality water and use it to irrigate and let the bad stuff pass. Thus, trying to protect the beneficial use which in this case is irrigated agriculture. In the Tongue River basin, irrigators tend to use sprinkler irrigation, which is a more efficient irrigation practice as it does not cause as much leaching through the soil profile. Leaching through the soil profile is very important in terms of taking some of the salt out. In the Powder River basin, . irrigators tend to use flood irrigation which is a little more forgiving. It tends to put more water on ' when it's available and lose more salt through the profiles. There's a relationship between sodium absorption ration, how high the SAR can get on the soil, or soil water relative to the salinity. With higher salinity the soil can actually take higher SAR's and still not fall apart. A third factor that comes into play is rainfall. Rainfall is basically close to distilled water and so it moves the salts out of the top portion of the soil more rapidly than a change in SAR, for example. Another point we heard about on the field trip is adjusting agricultural practices to use CMB water, which may be a good idea as a water disposal mechanism. But in terms of protecting bur water supply sources, we don't feel it's appropriate to pass along the cost to let the water degrade to the point where our ag producers have to pay to better the soil. Prices range from $50-$200 per acre and we don't feel that's appropriate. Further, there may be an issue relative to our state water quality law and rules where we would basically be letting an exiting use modify an existing use to less protective status. That's not s9mething we could do very easily. John and Bob were asked to talk about the politics of their respective state's standards. It's a huge economic thing in Wyoming and there's a lot of sensitivity to the issue. There's a lot of pressure coming from the State of Wyoming from the operators. At issue is the agricultural folks in Montana in their political "cloud" verses the political cloud that CBM offers in Wyoming. Bob stated that Montana's governor was very much involved in conservation districts in the past. The 2003 standards were put into place under the former governor. In fact, she had the opportunity to replace the environmental chair and she let him stay while this activity was ongoing. There are ag . producers that want the water and there are others that say, "Get it out of here." 6