From: RICHERSON Phil [Richerson.Phil@deq.state.or.us] Sent: Friday, June 26, 2009 2:39 PM To: Said Amali; Barry Norris Subject: DEQ Comments on IRZ's June 2009 document "Conceptual Hydrogeology of Alluvial Aquifers" Hello Said and Barry, I have reviewed the referenced document and offer the following comments: 1. I think the major lesson learned from the Echo Meadows recharge was that nitrate can be leached from a fallow field during recharge. Therefore, we need dedicated recharge sites so that we don’t periodically flush nitrate (and potentially pesticides) to the groundwater. 2. I suggest you incorporate water levels from Hinkle Rail yard, Simplot Plant site, Simplot Terrace site, and Simplot Levy site to expand and refine the potentiometric surface maps. The largest refinement would likely be along the northern boundary of Echo Meadows. Beneath the Simplot Plant site, water levels drop significantly from the south side of the River (about 540 at MW-49) to the north side of the River (about 500 at MW-13s). MW-49 is no longer regularly monitored. It was monitored 39 times between February 1996 and August 2005. Water elevations ranged from 536.66 to 541.36 and averaged 538.98. MW-13s was monitored 57 times between February 1994 and May 2008. Water elevations ranged from 495.98 to 506.04 and averaged 500.69. These measurements suggest the 540, 550, and 560 contours should be further up-river which causes a more northerly flow direction than is indicated on your maps. They also suggest groundwater beneath Hinkle flows westerly, but groundwater beneath Simplot Plant site flows north/northwesterly (i.e., groundwater does not seem to flow towards the River from the north). Including water levels from the Simplot Terrace site allows you to wrap the 550 through 600 contours around the Service Anticline (although they probably should be identified as inferred). On the south side of Echo Meadows, water levels from the Simplot Levy site suggest groundwater flows down Service Canyon and Spikes Gulch and enters the southwest portion of Echo Meadows. 3. A few data points on the water level maps do not fit the contours. For example, the water level at DMDW3 doesn’t fit the contours on Figure 14 (an extended or additional 620 contour is needed). Another example is the elevation 556.82 west of LLPW1 on Figure 13. 4. On Figure 12, the 595 contour should be south of DMPW1, and the 600 contour should be closer to U1269. 5. On Figure 13, the 600 and 610 contours should be farther north so that the 600 contour is much closer to DMPW-4. Also, CPDW1 doesn’t fit the contours. 6. Groundwater occurs in alluvial sediments in areas other than those indicated in Figure 3. Perhaps Figure 3 should be labeled as coarse grained aquifers or productive aquifers or something like that. It should also be mentioned in Section 3.1 where Figure 3 is referenced. 7. The text concludes there is a connection between groundwater and the Umatilla River but the water table maps don’t really show this. 8. In the last paragraph of Section 3.2.2, a reference to the LUB GWMA (and perhaps a link to the web page) would be appropriate. 9. In Section 4.4, the statement is made that the detection of fecal coliform in wells is perhaps associated with decaying vegetation. I don’t think fecal coliform comes from decaying vegetation. 10. In Section 4.4, the last bullet on page 17 indicates nitrate was both detected in all wells samples, and nitrate was only detected in some wells. 11. In Section 5.4.3, a URL is given for the Depot and is identified as an ODEQ website. That web site is actually a USEPA web site. 12. Figure 35 is referenced, but not included. I hope you find these comments useful. ~Phil ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Phil Richerson Nonpoint Source Hydrogeologist Oregon Dpt of Environmental Quality 700 SE Emigrant, Suite 330 Pendleton, OR 97801 (541) 278-4604 (541) 278-0168 fax 1-800-452-4011