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HomeMy WebLinkAbout2017 Wahl Extraction Area Groundwater Monitoring Report 1101 South Fawcett Avenue, Suite 200 Tacoma, Washington 98402 253.383.4940 August 6, 2018 Miles Sand & Gravel Company 400 Valley Avenue NE Puyallup, Washington 98372 Attention: Ryan Ransavage Subject: Letter Report 2017 Groundwater, Surface Water and Precipitation Monitoring Data Shine Facility – Wahl Extraction Area Jefferson County, Washington File No. 1355-035-04 Monitoring requirements at the Shine Facility were set forth by Jefferson County Department of Community Development (DCD) as conditions of the Wahl Permit (MLA03-0037), dated July 18, 2005, prepared originally for Fred Hill Materials (FHM) and Ordinance 08-0706-04 (MLA10-00073), Amendment 09-1213-10 dated December 18, 2010. The purpose of this letter is to provide a summary of the water monitoring program implemented for the Wahl Extraction Area (WEA) through December 31, 2017 and to compare the high groundwater table elevations with the proposed excavation elevations at the WEA. PREVIOUS AND CURRENT MONITORING The original monitoring, initiated in August 2005, was conducted by CR Hydrogeologic Consulting FHM. GeoEngineers, Inc. (GeoEngineers) assumed the monitoring duties in November 2009 when Miles Sand & Gravel Company (Miles) commenced leasing the operations at the WEA. The monitoring locations are shown on Figure 1. The following are elements of the current monitoring program: Groundwater ■ Groundwater level monitoring at the WEA began in August 2005 with the installation of an automated water-level sensor (consisting of a combined pressure transducer and datalogger) in monitoring well MW-9, a monitoring well located in the southwest portion of the WEA. The automated sensor measures and records the groundwater level on an hourly basis and the information is downloaded quarterly during a visual inspection of the site. The monitoring equipment has provided reliable data since 2005. ■ A water-level sensor was installed in the Shine Hub water supply well in April 2007. The sensor malfunctioned in June 2010 and was replaced in September 2010 with new equipment from the same Miles Sand & Gravel Company | August 6, 2018 Page 2 File No. 1355-035-04 manufacturer. The sensor malfunctioned again in April 2013 and was repaired and reinstalled in July 2013. With the exception of a few months in 2010 and in 2013, the monitoring equipment has provided reliable data. ■ In January 2010, additional monitoring wells (MW-5 and MW-8) equipped with sensors were added by Miles to estimate a groundwater surface profile beneath the WEA. The installed sensors are from the same manufacturer as those installed in monitoring well MW-9 and the Shine Hub well. The current monitoring equipment provides reliable data. ■ In 2012, monitoring well MW-5 was deepened to explore for a groundwater supply for the facility. The exploration was unsuccessful and MW-5 was decommissioned. Thus, the water level sensor from MW-5 was moved to monitoring well MW-15 on February 15, 2012. MW-15 is located approximately 550 feet south of the proposed mining area and now provides a monitoring point for the southern portion of the WEA. ■ In July 2015, the vented transducer in MW-8 stopped functioning and was replaced on October 2015 with a new non-vented transducer (INW PT2X 50-psi). ■ By late 2016, excavation had progressed to the area surrounding monitoring well MW-9 and the wellhead was nearly inaccessible. Therefore, the transducer in MW-9 was removed on November 7, 2016. ■ In early 2017, excavation removed the materials surrounding MW-9 leaving the top of the well casing approximately 50 feet in the air. Monitoring well MW-9 was not accessible during 2017. The MW-9 casing will be modified and the transducer will be reinstalled in MW-9 after the excavation and reclamation surrounding MW-9 is completed. Surface Water ■ Three surface water stations were established in September 2005 on Thorndyke Creek near the WEA. One of the stations (Station 3) is located on an unnamed tributary and two are located on Thorndyke Creek, with Station 2 upstream and Station 1 located downstream of the confluence with the unnamed tributary. The stream stage height at each station is recorded on an hourly basis using an automated sensor. The streamflow is measured manually on a quarterly basis by wading the stream and measuring stream velocity. ■ An additional surface water monitoring point (Station 4) is located on Thorndyke Creek approximately 1 mile upstream of its mouth. The stream stage height is recorded on an hourly basis using an automated sensor. The stream flow is measured manually on a quarterly basis by wading the stream and measuring stream velocity. The sensor installed at Station 4 malfunctioned in April 2014 and was repaired and reinstalled in June 2014. ■ The automated equipment previously installed at the surface water stations was replaced at all four stations in 2011 and 2012 with more reliable sensors. ■ The stream channel at Stations 1 and 3 bifurcated in early 2017, which resulted in the formation of a gravel bar where the staff gages were located. Thus, recorded staff gage readings are below their respective staff gages. Miles Sand & Gravel Company | August 6, 2018 Page 3 File No. 1355-035-04 ■ The stream channel and staff gauge at Station 2 were affected by a small log jam sometime between the winter and spring 2017 monitoring events. The logs damaged the staff gauge tape and caused a slight tilt to the staff gauge. The logs were removed during the spring monitoring event to prevent further damage to the staff gauge and the gauge tape was replaced. ■ The stream channel at Station 4 bifurcated in early 2017, resulting in the formation of a gravel bar in the middle of the stream and deepening of the channel at the staff gauge location. The condition of the staff gauge will be assessed during 2018 monitoring events to determine if the gauge needs to be reinstalled at a greater depth. ■ In January 2017 we could not communicate with the transducer installed at Station 3. The transducer was removed, sent in for repair, and reinstalled in June 2017. ■ In May 2017 the transducer at Station 2 malfunctioned and was brought back to the office for repair. It was reinstalled in June 2017 but was subsequently moved to Station 1 by Ryan Ransavage and replaced with a new transducer in July 2017. ■ In October 2017 the transducer at Station 1 malfunctioned and was brought back to the office for repair. It was reinstalled in November 2017. ■ New staff gage tapes were installed at Stations 1, 2 and 4 in July 2017. Precipitation ■ A weather station was established on the roof of the office building at the current Shine Hub in September 2005. The data, collected on an hourly basis, includes precipitation, temperature and wind direction and speed. Between March 14 and October 17, 2012, the weather station experienced a loss of data. Periodic data losses from September 1, 2013 through December 31, 2016 have occurred as a result of damage caused by power outages at the site. Therefore, the data for 2013 through 2016 is incomplete. A comparable dataset was acquired for January 1, 2012 through December 31, 2017 from the Kitsap Public Utility District No. 1’s (KPUD) rain gage at Edgewater, located on the Kitsap Peninsula approximately 5 miles southeast of the WEA. MONITORING DATA SUMMARY GeoEngineers has developed plots of the monitoring data described below. Mining has commenced in the WEA and several years of background groundwater, surface water and precipitation data have now been acquired. Groundwater Data The elevations of the groundwater monitoring points (rims of the well casings) have been surveyed relative to the National Geodetic Vertical Datum (NGVD) 1929 datum. The water levels measured in each monitoring well have been converted to groundwater elevations. Figure 2 shows a plot of groundwater elevations from the four monitoring wells and the Shine Hub water supply well. The water supply well is located near the office buildings at the Shine Facility (Figure 1). Monitoring wells MW-5, MW-8 and MW-9 are located within the WEA; monitoring well MW-15 is located approximately 550 feet south of the WEA. Miles Sand & Gravel Company | August 6, 2018 Page 4 File No. 1355-035-04 Shine Hub Water Supply Well The hourly data from the Shine Hub water supply well are shown on Figure 2 as points because the well pump cycles on and off several times a day. The lowest water level elevations in the Shine Hub water supply well represent pumping water levels and the highest represent fully or nearly recovered water levels. The data in-between represent water levels that are either recovering or are being drawn down at various stages of the pumping cycle. Seasonal water level fluctuations in the supply well are similar to the other site monitoring wells (described below) located over a mile west of the Shine Hub well and are attributed to seasonal groundwater fluctuations. The groundwater elevation in the supply well showed a relatively sharp increase in early 2016 and a longer increase through the first half of 2017 (Figure 2). This pattern was also observed in MW-8, MW-9 and MW-15 in 2016 and in MW-8 and MW-15 in 2017 (MW-9 was not monitored in 2017). This may be a result of recharge from relatively large precipitation events in early 2016 and early 2017 (Figure 4). The effects of these precipitation events are also shown in the surface water monitoring records (Figure 3). However, the frequency and duration of pumping at the supply well was decreased starting in 2016, and the general trend of increasing water levels observed in the supply well may also be related to less groundwater extraction from the aquifer at that location. Monitoring Wells MW-5, MW-8, MW-9 and MW-15 The dataset with the longest period of record is for monitoring well MW-9, beginning in August 2005 through November 2016. The groundwater elevations in all the wells show similar seasonal fluctuations of rising levels in the winter wet months and declining levels between spring and fall. The highest recorded groundwater elevations for the monitoring wells were all recorded in May 2017. These groundwater elevations were 282.1 and 256.8 feet (NGVD 29) for MW-8 and MW-15, respectively (MW-9 was not monitored during 2017). These groundwater elevations are about 1 to 1 ½ feet higher than the previous highs seen in 2016. As discussed above, the trend of increasing groundwater elevations starting in 2016 in MW-8, MW-9 and MW-15 may be somewhat attributed to increased precipitation during the winters of 2016 and 2017. Surface Water Data Figure 3 shows a plot of the surface water data for Stations 1 through 4, located on Thorndyke Creek. Figure 3 shows the stage heights as recorded at a 30-minute interval using dataloggers. The stage height dataset has had relatively short periods when the data was lost due to faulty monitoring sensors. In each case, the equipment was replaced. Figure 3 also shows the streamflow rates calculated from flow velocities that were measured by wading the stream; these are plotted on a logarithmic vertical scale (right-hand axis). Station 1 The largest measured flow at Station 1, located near the WEA, was 3.0 cubic feet per second (cfs) during the January monitoring event and the lowest measured flow was 2.4 cfs during the October monitoring event. The stream channel at Station 1 experienced significant channel migration beginning in early 2016. Figure 3 shows a drop in recorded water levels following a large precipitation event in January 2016, which moved the channel west-ward and away from the staff gage. Miles Sand & Gravel Company | August 6, 2018 Page 5 File No. 1355-035-04 Station 2 The largest measured flow at Station 2 was 1.2 cfs during the January monitoring event and the lowest measured flow was 0.20 cfs during the October monitoring event. The stream channel position at Station 2 has meandered somewhat since at least 2013. As shown in Figure 3, measured surface water levels drop below the staff gage datum at times during 2013 through 2014 and in 2016 when the staff gage was near the bank or out of the channel. The channel had migrated back toward the staff gage in early 2015 as indicated by higher surface water levels throughout 2015. Station 3 The largest measured flow at Station 3 was 2.5 cfs during the January monitoring event and the lowest measured flow was 1.3 cfs during the July monitoring event. The stream channel at Station 3 migrated west-ward beginning in late 2016. In spring 2017, the stream channel bifurcated, and the staff gage was positioned at the edge of a center bar of the stream. Station 4 The largest measured flow at Station 4 was 19.6 cfs during the May monitoring event and the lowest measured flow was 16.7 cfs during the October monitoring event. The stream channel at Station 4 bifurcated in early 2017 resulting in the formation of a gravel bar in the center of the stream. Flow diverted around the gravel bar appears to be incising the channel at the location of the staff gage for Station 4. Significant channel migration was observed upstream of Station 4 that may have resulted from multiple fallen trees impacting stream flow. Based on the observations in 2017, the channel at this location appears to be migrating west-ward. Precipitation Data Figure 4 shows a plot of the daily precipitation at the weather station located on the roof of the Shine Hub office. The highest recorded daily precipitation event was 3.11 inches on December 3, 2007. As stated above, it appears from the downloaded data that the station has had periods of malfunction in 2012 and has recorded only partial data since September 2013. This is evident in the plot for 2012 through 2017. The Shine weather station data for 2012 through 2017 shown on Figure 4 is supplemented by data from the KPUD’s Edgewater rain gage as a substitute until the Shine weather station is repaired. Comparing days when both stations recorded data it appears that there has been significantly more rainfall at the Edgewater gage than recorded at the Shine weather station. GROUNDWATER ELEVATIONS VERSUS PROPOSED EXCAVATION FLOOR The proposed excavation elevations are shown on the attached plan titled “WDNR Permit No. 70-013024 Final Reclamation Map” as prepared by Team 4 Engineering. The plan shows that the excavation will stay 10 feet above the high groundwater table, as a currently required condition, in the central and north portions of the WEA. Miles proposes to excavate to Elevation 275 feet in the southernmost extent of the WEA. Prior to 2012, there was a lack of groundwater monitoring data points in this area. Monitoring of MW-15, located approximately 550 feet south of the southern WEA mining disturbance boundary (Figure 1), indicates that the highest water level recorded at MW-15 was Elevation 256.8 feet. Based on a uniform gradient between &( EDEDED ED @A @A @A @A @A Shine Hub Weather Station MW-15 MW-8 MW-5 MW-9 Shine Hub Water Supply WellWahl Lake Rd Thorndyke Rd UV104 Thorndyke Rd S Po in t Rd Peabody Way T h o r n d y k e R d µ Vicinity Map Figure 1 Shine Facility - Wahl Extraction AreaMiles Sand & Gravel CompanyShine, Washington !^ Olympia §¨¦90 §¨¦5 §¨¦405 £¤101 Olympic NP W a s h i n g t o n 3,000 3,0000 Feet Data Sources: ESRI Data & Maps, Street Maps 2005 Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication.3. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission. Transverse Mercator, State Plane South, North American Datum 1983North arrow oriented to grid northOffice: TACO Path: P:\1\1355035\GIS\135503500_F1.mxdMap Revised: 20 March 2012 syiEDED ED Station 1 Station 2 Station 3 200 2000 Feet Station 1Station 3Station 2 Station 4 Legend @A Monitoring Well ED Stream Gage &(Shine Hub Weather Station Wahl Extraction Area MW-5 Station 1 Tho m d y k e C r e e k Creek Groundwater DataShine Facility - Wahl Extraction AreaJefferson County, WashingtonFigure 22302402502602702802901/1/2005 1/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2010 1/1/2011 1/1/2012 1/1/2013 1/1/2014 1/1/2015 1/1/2016 1/1/2017 1/1/2018Water Level Elevation (Feet NGVD)DateShine Hub Water-Supply WellMonitoring Well MW-5Monitoring Well MW-8Monitoring Well MW-9Monitoring Well MW-15Moved transducerfrom MW-5 to MW-15 on May 2, 2012GeoEngineers, Inc. Data through 12/31/2017Transducer temporarily removed from MW-9 on November 7, 2016 because of excavation surrounding well. Surface Water DataShine Facility - Wahl Extraction AreaJefferson County, WashingtonFigure 30.1110100-1012Stream Flow (ft³/sec)Stage Height (feet)DateStation 1 Relative Stage HeightsWaded Stream Flow MeasurementsGeoEngineers, Inc. Data through 12/31/2017Stage height below staff datum0.010.1110100-101234Stream Flow (ft³/sec)Stage Height (feet)DateStation 2 Relative Stage HeightsWaded Stream Flow MeasurementsRelocated Station 2 approximately 300 feet upstream on February 15, 2011Faulty ReadingsSensor Replaced February 3, 2012Stage height below staff datumTransduer not functioning from January 13, 2017 to June 8, 2017GeoEngineers, Inc. Data through 12/31/20170.1110100-11357Stream Flow (ft³/sec)Stage Height (feet)DateStation 4 Relative Stage HeightsWaded Stream Flow MeasurementsSensor Replacedon May 6, 2011Transducer not functioning from April 16,2014 to June 27, 2014GeoEngineers, Inc. Data through 12/31/20170.010.1110100-10123Stream Flow (ft³/sec)Stage Height (feet)DateStation 3 Relative Stage HeightsWaded Stream Flow MeasurementsStream height below staff datumTransducer and/or Stilling Wellunder repair from November 7, 2016 to June 8, 2017Sensor Replaced May 6, 2011GeoEngineers, Inc. Data through 12/31/2017Notes:1. The stream channel at Station 1 bifurcated in early 2017, forming two channels that resulted in a gravel bar forming where the staff gage is located.2. The stream channel at Station 2 shifted such that the staff gage was located outside the wetted channel in 2013, 2014 and 2017. Precipitation DataShine Facility - Wahl Extraction AreaJefferson County, WashingtonFigure 4Notes:1. The computer that automatically downloads weather data at the Shine weather station was damaged in a power outage. The damage has affected precipitation data since 2012. Daily rainfall data was acquired from Kitsap Public Utilities District No. 1’s Edgewater Station gage, located approximately 5 miles to the southwest, for June 18, 2009 through December 31, 2017.012341/1/2005 1/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2010 1/1/2011 1/1/2012 1/1/2013 1/1/2014 1/1/2015 1/1/2016 1/1/2017 1/1/2018Daily Precipitation (inches)DateShine Weather StationKitsap PUD Edgewater Station ATTACHMENT 1 Wahl Reclamation Map