2017 Horseshoe Lake Emergency Pumping Groundwater …...2017 Horseshoe Lake Emergency Pumping – Groundwater Monitoring King County Science and Technical Support Section v May 2018

2017 Horseshoe Lake Emergency Pumping –

Groundwater Monitoring

May 2018

Alternate Formats Available

2017 Horseshoe Lake Emergency Pumping – Groundwater Monitoring Prepared for: Stormwater Services / Capital Services Unit / Water and Land Resources Division / King County Department of Natural Resources and Parks Submitted by: Eric Ferguson King County Water and Land Resources Division Department of Natural Resources and Parks

2017 Horseshoe Lake Emergency Pumping – Groundwater Monitoring

King County Science and Technical Support Section i May 2018

Acknowledgements Thanks to David Robinson and other King County Environmental Lab staff for collection assistance and analytical work. Further thanks are due to Golder Associates for their assistance in the field and collection of water level and pond level data, Oakpointe staff for permission to access the site and assistance to field staff, to the King County hydrology group for lake level data, and to the King County Stormwater Services Section for overseeing the emergency pumping project.

Citation King County. 2018. 2017 Horseshoe Lake Emergency Pumping Groundwater Monitoring.

Prepared by Eric Ferguson, Water and Land Resources Division. Seattle, Washington.


King County Science and Technical Support Section ii May 2018

Table of Contents Executive Summary............................................................................................................................................. iv

1.0 Introduction .............................................................................................................................................. 1

1.1 2017 Emergency Pumping ............................................................................................................. 1

1.2 Dry Weather Sampling ..................................................................................................................... 2

2.0 Methods ...................................................................................................................................................... 4

2.1 Water Level Data Collection .......................................................................................................... 4

2.2 Water Quality Data Collection ....................................................................................................... 5

2.2.1 Sample Collection ......................................................................................................................... 5

3.0 Results and Discussion ......................................................................................................................... 7

3.1 Emergency Pumping ......................................................................................................................... 7

3.1.1 Groundwater Levels .................................................................................................................... 7

3.1.2 Groundwater Water Quality .................................................................................................... 8

3.1.3 Wet Seasons Comparison ........................................................................................................10

3.2 Dry Season Sampling ......................................................................................................................15

3.2.1 Groundwater Levels ..................................................................................................................16

3.2.2 Groundwater Water Quality ..................................................................................................16

3.2.3 Dry Seasons Comparison ........................................................................................................17

4.0 Summary ..................................................................................................................................................19

5.0 References ...............................................................................................................................................20

Figures Figure 1. Horseshoe Lake Levels – 2009, 2011-17 for the entire water year – Oct 1 to

Sept 30. ............................................................................................................................................. 2

Figure 2. Horseshoe Lake Groundwater Monitoring Site Map. ..................................................... 3

Figure 3. Monitoring Well Wellhead Configurations. ....................................................................... 5

Figure 4. Rainfall Data – cumulative and daily totals for the Black Diamond rain gauge during water year 2017. . ............................................................................................. 8

Figure 5. Groundwater Levels for MW-10, MW-12, MW-13, MW-27, MW-29 and MW-30. ....................................................................................................................................................... 9

Figure 6. Groundwater Levels for MW-27, MW-10, MW-12 and MW-13. ..............................10


King County Science and Technical Support Section iii May 2018

Tables Table 1. Monitoring Well Information .................................................................................................. 4

Table 2. List of Parameters Collected for Surface Water and Groundwater Monitoring of the 2017 Emergency Pumping at Horseshoe Lake. ........................... 6

Table 3. Primary and Secondary Drinking Water Standards for Sampled Parameters. ..11

Table 4. Groundwater Water Quality Results for 2017. Results displayed in bold are above secondary drinking water standards shown in Table 3. ...............................12

Table 5. Total Iron concentrations for 2016 and 2017 wet season. ........................................14

Table 6. Sulfate concentrations for 2016 and 2017 wet season. ..............................................15

Table 7. Hardness for 2016 and 2017 wet season. ........................................................................15

Table 8. Depth to water measurements at the time of sampling. All units are feet. .........16

Table 9. Total iron concentration for 2016 and 2017 dry season............................................18

Table 10. Sulfate concentrations for 2016 and 2017 dry season. ...............................................18

Table 11. Hardness for 2016 and 2017 dry season. .........................................................................18

Appendices Appendix A: Water Level Data.

Appendix B: Water Quality Data from 2016 and 2017


King County Science and Technical Support Section iv May 2018

EXECUTIVE SUMMARY In water year 2017, the water levels of Horseshoe Lake increased to near-flood levels after another year of near-record total rainfall. The near-record rainfall also increased the groundwater levels that control the lake level in the winter. Pumping of the lake water to an infiltration site was performed intermittently from March 21 to May 9, 2017. Ten pumping events occurred during this time period ranging from one to four days of continuous pumping at variable rates. A total of 109 acre-ft was pumped from Horseshoe Lake in 2017. This report summarizes groundwater monitoring activities related to the 2017 Horseshoe Lake emergency pumping. Groundwater data were collected during (April) and after (August) the emergency pumping period from seven existing monitoring wells. Two types of data were collected:

• Water level data – this task was primarily completed by Golder Associates staff • Water quality data – this task was completed by King County WLRD staff

Groundwater levels rose at all sites due to the groundwater recharge associated with wet season rainfall. March is the typical time period for the groundwater high levels to occur for wells in the area. At the two wells nearest the infiltration site (MW-29 and MW-30), the water level data also showed short-term mounding responses [higher water table elevations] to the infiltration during the emergency pumping events. During periods of pumping, the water levels rose in both wells, with MW-30 recording a greater magnitude of change for the pumping periods than MW-29. When the pump was turned off, the water levels in these wells receded to background levels. Data from the other five wells (MW-10, MW-12, MW-13, MW-27, and MW-28) did not show any apparent responses from the pumping events, instead showing gradual increases in water levels associated with winter rainfall followed by gradual decreases as rainfall amounts decreased during the year. All sites had lower water levels at the time of sampling in August relative to the April event. The range of change was from -2.4 to -11.7 feet, with the exception of well MW-13, which was dry and yielded a difference of more than 14 feet. This range observed is similar to previously presented data showing the range of groundwater levels. Water quality sampling occurred at all seven monitoring wells during the emergency pumping event in mid-April 2017. Additional water quality sampling was completed after the emergency pumping period in late August 2017 at six sites; well MW-13 was dry (no water). No wells had water quality results above the primary drinking water standards. Although these wells are not intended for potable use, groundwater water quality results are typically compared to drinking water standards. Bacteria parameters (fecal coliform and Escherichia coli) were added to the list of water quality analytes in 2017 and none were detected at any of these monitoring sites. The results of three parameters, total iron, total aluminum and pH, had values above the secondary drinking water standards – guidelines for aesthetic considerations, such as taste, color, corrosion, and odor. Wells MW-10, MW-


King County Science and Technical Support Section v May 2018

12, MW-13 and MW-29 had total iron concentrations greater than the standard of 300 µg/L. Well MW-29 had total aluminum concentrations greater than the standard of 200 µg/L. Wells MW-27, MW-29 and MW-30 had pH values below the secondary standard of 6.5. All other wells had pH values between 6.5 and 8.5. Well MW-10 is the deepest well sampled and differed from the other wells in regard to the following parameters: higher pH, conductivity, hardness, total alkalinity, and lower dissolved oxygen. These differences infer a deeper, longer groundwater flow path at this site when compared to the other sites sampled. Overall, water quality in 2017 is similar to the previous sampling events in 2016. Any differences, such as dissolved oxygen, conductivity, sulfate and alkalinity may be reflective of seasonal variability; however, additional sampling would be necessary to confirm this or other natural variability. The water levels at all sites showed seasonal variability with all sites having lower water levels in summer compared to spring levels. Only two sites, MW-29 and MW-30, showed a water level response to the emergency pumping to the infiltration facility. This response is a mounding of water (higher water levels) during active pumping periods. No other wells appear to show a water level response to pumping activity.


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King County Science and Technical Support Section 1 May 2018

1.0 INTRODUCTION Horseshoe Lake is a closed depression in southeast King County located west of the City of Black Diamond, Washington. The lake water surface elevation rises and falls seasonally in response to groundwater pressure and surface runoff. Prolonged wet weather increases lake inflows, which some years causes lake levels to rise enough to impact surrounding homes and roads with flooding. King County has responded to these episodes by pumping water from the lake to nearby locations that have the capacity to drain the water away from the area. King County has previously pumped down the lake level in 1991, 1996, 1997, 2007, 2009, 2011, 2014, and 2016. During these pumping events, County staff monitored various environmental factors in the area to determine water quality/quantity impacts, if any, from the pumping events. Monitoring of levels in the lake and receiving water is part of these activities. Groundwater water quality was monitored for the first time in 2016 (King County, 2017). In water year 2017, the water levels of Horseshoe Lake increased to near-flood levels after another near record year of precipitation (October through May)1, raising the groundwater levels that control the lake level in the winter (Figure 1). This report summarizes King County activities related to groundwater monitoring for water year 2017.

1.1 2017 Emergency Pumping King County Water and Land Resources Division (WLRD) decided to conduct emergency pumping of the lake due to a rapid and steady rise in lake levels that occurred during March 2017, Figure 1. Water was pumped from the lake to the location of a proposed regional stormwater facility on property owned by Oakpointe, LLC, located to the south of the lake (Figure 2). An infiltration test facility was previously constructed at this location. Monitoring and analysis performed by the company’s subcontractor, Golder Associates, indicated that water pumped to the infiltration test facility would infiltrate with little or no resulting increase in surface flows in nearby creeks or rivers, (Golder, 2013). Representatives from the Muckleshoot Indian Tribe expressed concern about the new infiltration facility because of the sensitivity of their hatchery operation located downstream. King County WLRD Science and Technical Services staff carried out water quality monitoring in 2016 and 2017 similar to that completed in 2014 (King County, 2014a & 2014b). In 2016, water quality monitoring included groundwater sites in addition to surface water sites. For 2017 water quality monitoring, two new parameters were added along with ‘total’ metals (see Section 2.2.1).

1 Record rain amounts as measured at SeaTac, the area reference point for precipitation: http://green2.kingcounty.gov/streamsdata/Precip.aspx

http://green2.kingcounty.gov/streamsdata/Precip.aspx



Figure 1. Horseshoe Lake Levels – 2009, 2011-17 for the entire water year – Oct 1 to Sept 30.

This chart shows the elevation of the lake level for various years of monitoring; most recent monitoring year – 2017 shown as the black dashed line. Units are feet above mean sea level.

Emergency pumping was performed from March 21 to May 9, 2017. Ten pumping events occurred during this time period ranging from 1 to 4 days of continuous pumping at variable rates. A total of 109 acre-ft was pumped from Horseshoe Lake into the infiltration facility (King County, 2017).

1.2 Dry Weather Sampling Additional groundwater water quality sampling was conducted in August (the dry season) similar to 2016. This sample event was carried out using the same methods, procedures, and parameters as during the emergency pumping event. Results from this sample event are presented after the emergency pumping event results in Section 3.2.



Figure 2. Horseshoe Lake Groundwater Monitoring Site Map. Seven monitoring wells in the

vicinity of the infiltration facility were monitored for water level changes and water quality during this emergency pumping.

Horseshoe Lake

Pipeline (approx.)

Infiltration facility



2.0 METHODS Groundwater data were collected from seven existing monitoring wells (Figure 2 and Table 1). Permission to sample at these locations was obtained from Golder Associates and Oakpointe, LLC. Two types of data were collected as part of the groundwater monitoring related to the emergency pumping of Horseshoe Lake:

• Water level data – this task was primarily completed by Golder Associates staff • Water quality data – this task was completed by King County WLRD staff

Table 1. Monitoring Well Information

Well id Elevation Well depth

Well diameter Geo unit X coord Y coord Source KC locator

MW-10 581.7 173.0 6 Qpog1c 1339796 110665 Golder SEKC_mw-10 MW-12 532.9 78.5 6 Qpog1c 1340714 109074 Golder SEKC_mw-12 MW-13 532.9 48.9 6 Qpog1s/Qvr 1340715 109071 Golder SEKC_mw-13 MW-27 526.8 55.0 2 Qpog1c 1339244 111842 Golder SEKC_mw-27 MW-28 510.2 40.0 2 Qpog1c 1339198 111371 Golder SEKC_mw-28 MW-29 556.8 70.0 2 Qpog1s 1341069 111533 Golder SEKC_mw-29 MW-30 553.6 69.0 2 Qpog1s 1341076 110931 Golder SEKC_mw-30

Units for elevation (above mean sea level) and well depth are feet and well diameter is inches – data provided by Golder, 2016. Coordinates are shown as State Plane Feet – North. Geo unit refers to geologic unit assigned to the screen zone in previous reports (Golder 2013); “c” refers to a coarse sand units and “s” refers to a silty sand units; Qvr refers to coarse sand +/- gravel units.

2.1 Water Level Data Collection Data loggers were deployed by Golder Associates in all wells except for MW-12 and MW-28 in 2015. King County provided and deployed data loggers in these locations. All staff collected manual depth to water level measurements at the time of downloading data loggers. King County staff took manual depth to water level measurements at each well before and after sampling. At well sites with two-inch diameter casing (MW-27- 30), the data loggers were removed from the well before sampling began and after depth to water level measurements were recorded. The data loggers were replaced in the wells after sampling. Note: the data loggers deployed in MW-28 were removed (stolen) after deployment on March 22 and before sampling occurred on April 19. It is unknown who cut the lock and removed this equipment. No additional equipment was deployed in this site.



A. B. Figure 3. Monitoring Well Wellhead Configurations.

A. Monitoring well MW-12 – 6” well; This configuration applies to wells MW-10, 12 and 13. B. Monitoring well MW-27 – 2” well; This configuration applies to wells MW-27 through 30.

2.2 Water Quality Data Collection Water quality samples were collected by King County WLRD staff. Monitoring wells were purged and sampled for all parameters using low-flow purging methods (see King County, 2014c for details of this method).

2.2.1 Sample Collection The wells were purged by pumping a small volume of water to ensure sampled water represented aquifer conditions. The volume pumped was determined in the field based on stabilization of field parameters (King County, 2014c). Wells were purged slowly with a Grundfos pump set at a depth corresponding to roughly the top of the screen zone, securing



the tubing to prevent vertical movement and then pumping at a rate not to exceed water levels dropping into the pump zone (a rate of about two gallons per minute or less). The water quality parameters collected were the same as measured during the surface water sample collection effort (King County, 2018). In 2017, two additional parameters were added to the list – fecal coliform and Escherichia coli. The list of parameters included field parameters, nutrients, selected metals (dissolved and total), bacteria, and selected conventionals (see Table 2). Table 2. List of Parameters Collected for Surface Water and Groundwater Monitoring of the 2017

Emergency Pumping at Horseshoe Lake.

Parameters Sample Temperature, Field Aluminum, Total & Dissolved Dissolved Oxygen, Field Arsenic, Total & Dissolved Conductivity, Field Beryllium, Total & Dissolved pH, Field Cadmium, Total & Dissolved Turbidity, Field Calcium, Total & Dissolved Orthophosphate Phosphorus Chromium, Total & Dissolved Total Phosphorus Copper, Total & Dissolved Ammonia Nitrogen Iron, Total & Dissolved Nitrite + Nitrate Nitrogen Lead, Total & Dissolved Total Nitrogen Magnesium, Total & Dissolved Sulfate Manganese, Total & Dissolved Total Alkalinity Nickel, Total & Dissolved Total Suspended Solids Selenium, Total & Dissolved Escherichia coli Silver, Total & Dissolved Fecal Coliform Thallium, Total & Dissolved Hardness, Calc Zinc, Total & Dissolved



3.0 RESULTS AND DISCUSSION

3.1 Emergency Pumping From March 21 to May 9, 201, pumping of the lake occurred ten times as noted earlier. During the groundwater sampling dates, no active lake pumping occurred. Groundwater water quality sample collection began on April 17th and was completed on April 19th. The following sites were sampled on these dates:

• MW – 12 – sampled on 4/17/17 • MW – 13 – sampled on 4/17/17 • MW – 10 – sampled on 4/18/17 • MW – 27 – sampled on 4/19/17 • MW – 28 – sampled on 4/19/17 • MW – 29 – sampled on 4/17/17 • MW – 30 – sampled on 4/18/17

3.1.1 Groundwater Levels Groundwater recharge is affected by the amount of rainfall. Near record rainfall totals have occurred in the area for the past two years. In water year 2017, this area had more rain (>11 inches) through mid-May compared to the historical mean (WY2001-2016) (Figure 4). The rain gauge near Black Diamond (King County gauge: BDIA) measured 52.8 inches compared to the historical mean value of 41.2 inches over the same time period (Figure 4). Groundwater levels in monitored wells rose at all sites during the emergency pumping period due to the groundwater recharge. Previous studies have shown that March is the typical time period for high groundwater levels to occur for wells in the area (Golder, 2013). The water levels at these sites have been shown to vary up to seven feet or more during previous monitoring events (Golder, 2013). At wells MW-29 and MW-30, the two wells closest to the infiltration facility, data-logger water level data show a mounding response to the infiltration during the emergency pumping (Figure 5). During periods of pumping, the water levels rose in both wells, with MW-30 recording a greater magnitude of change for the pumping periods (Figure 5). When the pump was turned off, the water levels in MW-29 and MW-30 slowly recovered to background levels (Figure 5). Data from site MW-13 shows a peaking of water elevations in late March/early April which is typically response to the groundwater recharge (Figure 6). Groundwater table elevation slowly decline over the pumping period with no apparent response(s) from the pumping events (Figure 6). Sites MW-10, MW-12 and MW-27 did not show any response from the



Figure 4. Rainfall Data – cumulative and daily totals for the Black Diamond rain gauge during

water year 2017. Data presented through 5/31/2017 while the water year continues until September 30. Data from water year 2016 (another emergency pumping year) is shown for comparison. Water year 2017 had the highest cummulative level as of mid-May. Water year 2017 is shown as red line; Water year 2016 is the green line; and the mean values are shown as the dark blue line.

emergency pumping activity; only seasonal variability (Figure 6). The data logger from MW-28 was removed from the well; no data is available. It is unknown who took the data logger. Depth to water (DTW) level measurements collected during routine site visits confirm the changes seen in the data logger data. Most DTW data were collected at the time of sampling and/or data download (see Appendix A). Depth to water level data collected by Golder Associates was not available at the time of publication.

3.1.2 Groundwater Water Quality The water quality sampling was completed on three days. The high turbidity issues noted in 2016 were greatly reduced in 2017. All sites had initial turbidity levels close to acceptable levels (<15 NTUs).

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Black Diamond Rain Gage: 10/01/2016 - 05/31/2017

Rain (in) cumm_BDIA_17 cumm_BDIA_16 Mean



Figure 5. Groundwater Levels for MW-10, MW-12, MW-13, MW-27, MW-29 and MW-30. Data

presented are from 2/1 to 9/30/2017. All sites were recording data hourly except well MW-29 was recording data every 4 hours. Well MW-12 had logger deployed starting 3/22/2017. Wells MW-29 and MW-30 show a mounding response (higher water table elevation) to the infiltration of water while the other sites do not. Gaps in records are periods where the logger was removed from the well during pumping/sample collection.

Table 3 contains the primary and secondary drinking water standards for sampled parameters. Groundwater water quality results are typically compared to drinking water standards even though these sites are not for potable use. Results for water quality sampling are presented in Table 4. No sites had results above the primary drinking water standards (Table 3 and Table 4). Three parameters, total iron, total aluminum and pH, did have results beyond the secondary drinking water standards (Table 3 and Table 4). Secondary drinking water standards are established based on aesthetic considerations such as taste or color. Wells MW-10, MW-12, MW-13, and MW-29 had total iron concentrations greater than the standard of 300 µg/L. Well MW-29 had total aluminum concentrations greater than the standard of 200 µg/L. Wells MW-27, MW-29, and MW-30 had pH values below the secondary standard of 6.5.



Figure 6. Groundwater Levels for MW-27, MW-10, MW-12 and MW-13. Data presented are from

2/01/17 to 9/30/2017. Data was recorded hourly. Data shows the seasonal variability noted in previous work. No water in well MW-13 below elevation of 484 feet.

Since water quality sampling has occurred at these sites in 2016 and 2017, a comparison of sampling results was done by season (wet versus dry) of collection period. With only 2 samples from each season, it is still unknown what the natural variability is for these locations.

3.1.3 Wet Seasons Comparison In the previous monitoring of emergency pumping of Horseshoe Lake (King County, 2014b and 2016) several parameters—total iron, dissolved aluminum, sulfate, and hardness—were discussed as parameter of interest due to the proximity of the hatchery. Total iron results are discussed above with four of the seven wells having higher total iron concentrations greater than the secondary standard (300 µg/L). Having high iron concentration can be related to increased suspended sediments in the groundwater from pumping and/or well development issues. However in 2017 unlike 2016 results, only one of these wells (MW-29) had higher turbidity values (10 NTUs) and high total suspended solids (TSS) value of 29.6 mg/L that infer the total iron concentrations are likely associated with suspended sediments (Table 4). Higher levels of iron and manganese are common in glacial sediments associated with older geologic units such as Qpog which is the geologic



Table 3. Primary and Secondary Drinking Water Standards for Sampled Parameters.

A. Primary Drinking Water Standards;

Parameter MCL* units MCL (µg/L)

Fecal Coliform >1 CFU/100ml - Arsenic 0.01 mg/L 10 Barium 2.0 mg/L 2,000 Beryllium 0.004 mg/L 4 Cadmium 0.005 mg/L 5 Chromium 0.10 mg/L 10 Copper 1.3 mg/L 1,300 Lead 0.015 mg/L 15 Mercury 0.002 mg/L 2 Nickel 0.1 mg/L 100 Nitrate as N 10.0 mg/L 10,000 Selenium 0.05 mg/L 50 Thallium 0.002 mg/L 2

B. Secondary Drinking Water Standards.

Parameter MCL* units MCL (µg/L)

Aluminum 0.05 to 0.2 mg/L 200 Copper 1 mg/L 1,000 Iron 0.3 mg/L 300 Manganese 0.05 mg/L 50 pH 6.5-8.5 pH units - Silver 0.1 mg/L 100 Sulfate 250 mg/L 250,000 Zinc 5 mg/L 5,000

“MCL” = refers to Maximum Contamination Level; from WAC 173-200-040 and US EPA. Units: mg/L = milligrams per liter; µg/L = micrograms per liter; CFU/100ml = colony forming units per 100 milliliters. unit many of these wells are screened in (King County, 2004 and Golder, 2013). This infers that the iron concentrations are likely naturally occurring due to the older geologic units in the area. All sites except MW-13 had lower total iron concentrations in 2017 (Table 5). Dissolved aluminum concentrations were typically below the detection limit of 2 µg/L for most wells in 2017 except for MW-28 and MW-29 which had results of 10.2 and 3.9 µg/L, respectively. Total aluminum was added in 2017. These results were much higher ranging from 2 to 1390 µg/L (Table 4).



Table 4. Groundwater Water Quality Results for 2017. Results displayed in bold are above secondary drinking water standards shown in Table 3.

MW-10 MW-12 MW-13 MW-27 MW-28 MW-29 MW-30 date date date date date date date

PARMNAME UNITS 4/18/2017 8/30/2017 4/17/2017 8/29/2017 4/17/2017 8/29/2017 4/19/2017 8/30/2017 4/19/2017 8/30/2017 4/17/2017 8/31/2017 4/18/2017 8/29/2017 MDL RDL Conductivity, Field umhos/cm 162 162 68.8 77.7 68.9

Not sam

pled - dry well

85.6 128 153 145 49.1 55.1 72.3 77.8 0.5 10 Dissolved Oxygen, Field mg/L 5.8 1.3 11.5 8 11.3 9.9 6 7.7 8.1 11.4 10.4 10.6 8.1 0.5 1 pH, Field pH 7.18 7.75 6.67 6.61 6.66 6.41 6.47 6.77 6.69 6.04 6.16 6.4 6.43 Temperature, Field deg C 10.5 11.3 9.6 9.7 9.6 9.7 10.7 10 10.1 9.7 11 10.7 13.1 Turbidity, Field NTU 4.2 3.2 2.8 8.8 2.3 2.6 1.7 3.1 1.8 10 2.2 2.9 8.6 0.5 2 Aluminum, Dissolved µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL 10.2 <MDL 3.9 <MDL <MDL <MDL 2 10 Aluminum, Total µg/L <MDL 2.2 3 3.1 10 69.6 49.6 102 97.7 1390 465 118 109 2 10 Ammonia Nitrogen mg/L <MDL 0.003 <MDL 0.0178 <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.002 0.01 Antimony, Dissolved µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.3 1 Antimony, Total µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.3 1 Arsenic, Dissolved µg/L 0.5 0.348 0.17 0.293 0.12 0.19 0.19 0.35 0.34 <MDL 0.1 0.13 0.16 0.1 0.5 Arsenic, Total µg/L 0.48 0.341 0.17 0.339 0.13 0.21 0.2 0.39 0.443 0.4 0.22 0.17 0.2 0.1 0.5 Beryllium, Dissolved µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.1 0.5 Beryllium, Total µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.1 0.5 Cadmium, Dissolved µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.05 0.25 Cadmium, Total µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.05 0.25 Calcium, Dissolved µg/L 20000 21400 6220 7270 6180 8320 14100 18000 17400 4380 5250 5380 6040 50 50 Calcium, Total µg/L 20600 22300 6270 7490 6310 8350 14400 18200 21400 4690 5500 5480 6270 50 50 Chromium, Dissolved µg/L 0.24 0.26 <MDL <MDL <MDL 0.21 0.34 0.45 0.40 0.41 0.33 0.38 0.74 0.2 1 Chromium, Total µg/L 0.43 1.07 0.40 0.32 0.40 0.52 0.47 1.14 0.75 2.78 1.16 0.91 2.10 0.2 1 Copper, Dissolved µg/L <MDL <MDL <MDL <MDL 0.43 0.28 0.35 0.56 0.21 0.32 <MDL 0.35 0.25 0.2 2 Copper, Total µg/L <MDL <MDL <MDL 0.22 0.73 0.51 0.40 0.57 0.52 2.66 0.89 0.58 0.41 0.2 2 Escherichia coli CFU/100ml <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 1 Fecal Coliform CFU/100ml <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 1 Hardness, Calc mg CaCO3/L 71.9 76.6 27.1 30.8 27.5 32.6 54.4 66.1 76.1 17.8 19.6 27.2 30.4 0.331 0.331 Iron, Dissolved µg/L 40 339 72.2 31 <MDL <MDL <MDL 11 <MDL <MDL <MDL <MDL 59.1 10 50 Iron, Total µg/L 420 743 376 1590 460 69.6 53.5 117 115 865 296 134 190 10 50 Lead, Dissolved µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.18 <MDL <MDL <MDL <MDL <MDL 0.1 0.5 Lead, Total µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.27 0.13 <MDL <MDL 0.1 0.5 Magnesium, Dissolved µg/L 4800 4980 2820 2930 2890 2900 4390 4760 4510 1210 1350 3120 3510 50 50 Magnesium, Total µg/L 5000 5070 2780 2940 2860 2860 4490 5020 5520 1470 1420 3280 3570 50 50 Manganese, Dissolved µg/L 3.78 15.9 5.24 3.93 0.768 0.694 0.994 0.647 <MDL 0.588 0.44 6.61 29.4 0.1 0.5 Manganese, Total µg/L 5.72 22.3 8.25 17.6 3.42 2.58 2.15 5.29 4.87 27.5 10.5 11.1 32.9 0.1 0.5 Nickel, Dissolved µg/L 0.20 0.44 0.14 0.16 0.20 0.24 0.32 0.51 0.22 0.61 0.21 0.79 1.45 0.1 0.5 Nickel, Total µg/L 0.29 0.98 0.30 0.34 0.52 0.50 0.44 0.83 0.52 2.73 1.03 1.24 2.30 0.1 0.5 Nitrite + Nitrate Nitrogen mg/L 0.69 0.73 0.45 0.57 0.41 1.86 0.92 1.35 2.13 1.74 1.06 2.37 1.70 0.01 0.04



MW-10 MW-12 MW-13 MW-27 MW-28 MW-29 MW-30 date date date date date date date PARMNAME UNITS 4/18/2017 8/30/2017 4/17/2017 8/29/2017 4/17/2017 8/29/2017 4/19/2017 8/30/2017 4/19/2017 8/30/2017 4/17/2017 8/31/2017 4/18/2017 8/29/2017 MDL RDL Orthophosphate Phosphorus mg/L 0.008 0.004 0.010 0.016 0.011 0.006 0.007 0.008 0.008 0.005 0.010 0.003 0.003 0.0005 0.002 Selenium, Dissolved µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.5 1 Selenium, Total µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.5 1 Silver, Dissolved µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.04 0.2 Silver, Total µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.04 0.2 Sulfate mg/L 6.49 6.32 2.4 3.03 2.46 3.38 6.34 6.66 5.44 1.73 2.06 2.35 2.81 0.1 0.2 Thallium, Dissolved µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.1 0.2 Thallium, Total µg/L <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL <MDL 0.1 0.2 Total Alkalinity mg CaCO3/L 67.7 71.2 26.6 31.4 26.8 27.1 49.5 60 55.2 11.4 16.6 19.8 25.2 1 5 Total Nitrogen mg/L 0.71 0.76 0.48 0.58 0.44 1.80 0.96 1.34 2.17 1.81 1.10 2.30 1.75 0.05 0.1 Total Phosphorus mg/L 0.014 0.017 0.018 0.023 0.016 0.011 0.010 0.013 0.012 0.029 0.018 0.011 0.014 0.005 0.01 Total Suspended Solids mg/L 0.7 0.7 0.7 2.2 0.7 0.9 0.6 1.2 1.0 29.6 7.3 5.0 4.6 0.5 1 Zinc, Dissolved µg/L <MDL <MDL <MDL <MDL <MDL <MDL 0.87 2.55 <MDL 0.95 <MDL <MDL <MDL 0.5 2.5 Zinc, Total µg/L 1.3 0.64 0.91 0.5 0.51 0.96 <MDL 0.97 <MDL 2.52 1.6 0.91 0.51 0.5 2.5 “RDL” = refers to Reporting Detection Limit; “MDL” = refers to Method Detection Limit; “<MDL” = refers to non-detects; Units: mg/L = milligrams per liter; µg/L = micrograms per liter; umhos/cm = micro-ohms per centimeter; deg C – degrees Celsius; NTU = nephalitic turbidity units; pH = pH units; mg CaCO3/L = milligrams of calcium carbonate per liter; CFU/100ml = colony forming units per 100 milliliters.



Table 5. Total Iron concentrations for 2016 and 2017 wet season.

Site Mar-2016 Apr-2017 SEKC_MW-10 822 420 SEKC_MW-12 1490 376 SEKC_MW-13 16 460 SEKC_MW-27 93 70 SEKC_MW-28 239 117 SEKC_MW-29 5470 865 SEKC_MW-30 598 134

Units are µg/L = micrograms per liter; Bold results are concentrations greater than the secondary standard of 300 µg/L, Table 3B.

Similar to 2016, the 2017 sulfate results ranged from 1.8 to 3.4 mg/L for 5 in seven wells, Table 6 and Appendix B. Wells MW-10 and MW-28 had results greater than 6 mg/L – 6.5 and 6.7, respectively. All samples were below the secondary standard of 250 mg/L.

Hardness calculations were similar in 2016 and 2017, Table 7. Hardness is a calculation of total calcium and magnesium in the sample. Values in 2017 were slightly lower in all wells except at well MW-28 had a slight increase in the hardness values from 2016 to 2017, 61.0 to 66.1 mg/L, Table 7. At this time, it is unknown how much annual variation naturally occurs.

No groundwater sites were sampled when Horseshoe Lake was actively pumping into the infiltration facility in 2017. Only one site, MW-29, was sampled during active pumping (in 2016). It is unknown if the infiltration water affected the water chemistry of this well. The high turbidity (38.1 NTU) and high total suspended solids (178 mg/L) from 2016 sampling are likely due to the lack of well development than a result of infiltration. Golder Associates informed King County (personal communication, 2016) that wells MW-27 through MW-30 were not developed after completion. Some parameters from well MW-29 have lower concentration than other sites, such as pH, conductivity, hardness, total alkalinity, and sulfate (Table 4 and Appendix B). These differences may be a result of pumped infiltration water or seasonal variability reflective of shallow (fast) groundwater recharge. Additional wet season sampling events are necessary to determine the background water quality of the groundwater in this area and to determine if there are any effects of pumping.



Table 6. Sulfate concentrations for 2016 and 2017 wet season.

Site Mar-2016 Apr-2017 SEKC_MW-10 6.9 6.5 SEKC_MW-12 2.6 2.4 SEKC_MW-13 2.6 2.5 SEKC_MW-27 3.7 3.4 SEKC_MW-28 6.1 6.7 SEKC_MW-29 1.8 1.7 SEKC_MW-30 3.4 2.4

Units are mg/L = milligrams per liter.

Table 7. Hardness for 2016 and 2017 wet season.

Site Mar-2016 Apr-2017 SEKC_MW-10 79.7 71.9 SEKC_MW-12 31.8 27.1 SEKC_MW-13 30.9 27.5 SEKC_MW-27 37.3 32.6 SEKC_MW-28 61.0 66.1 SEKC_MW-29 28.8 17.8 SEKC_MW-30 31.6 27.2


3.2 Dry Season Sampling Groundwater water quality sample collection began on August 29 and was completed on the 31st. The following sites were sampled on these dates:

• MW – 12 – sampled on 8/29/17• MW – 13 – not sampled; no water• MW – 10 – sampled on 8/30/17• MW – 27 – sampled on 8/30/17• MW – 28 – sampled on 8/30/17• MW – 29 – sampled on 8/31/17• MW – 30 – sampled on 8/29/17



3.2.1 Groundwater Levels All sites had lower water levels at the time of sampling in August as compared to the April event. The range of change was from -2.4 to -11.7 feet, with the exception of well MW-13, which was dry and yielded a difference of more than 14 feet. Table 8 presents the depth to water data from the two 2017 sampling events and the relative difference. This range observed is similar to previously presented data showing the range of groundwater levels (Golder Associates, 2013 and King County, 2016d).

Table 8. Depth to water measurements at the time of sampling. All units are feet.

Site April 2017 Depth To Water

August 2017 Depth To Water Difference

MW-10 97.7 104.3 -6.6MW-12 44.8 54.8 -10.0MW-13 37.1 Dry* > -13.9*MW-27 43.6 47.6 -4.0MW-28 28.9 31.3 -2.4MW-29 53.0 63.7 -10.7MW-30 48.7 60.4 -11.7

* = refers difference in depth to water data to bottom of well

3.2.2 Groundwater Water Quality Dry season water quality sampling was completed on three days in late August. The high turbidity issues noted in 2016 were greatly reduced in 2017, as with wet season sampling. All sites had initial turbidity levels close to acceptable levels (<15 NTUs). The lower turbidity levels are likely related to two issues: well development and timing of sampling event. Wells MW-27 thru 30 had not been developed prior to sampling in 2016 as noted previously (King County, 2016). Additional time was necessary to develop the well prior to sampling. The timing of the dry sampling event was done earlier, in late August compared to late September/October. This difference potentially allows for more water within the wells with higher water table elevations.

Results for water quality sampling completed in August are presented in Table 4. No exceedances to the primary drinking water standards are reported for this sampling event.

Three parameters (total iron, total aluminum, and pH) did have results beyond the secondary drinking water standards (Table 3B and Table 4). Wells MW-10 and MW-12 had total iron concentrations greater than the standard of 300 µg/L. Well MW-29 had total aluminum concentrations greater than the standard of 200 µg/L. Wells MW-27, MW-29 and MW-30 had pH values below the secondary standard of 6.5. These results are similar to the wet season sampling completed in April 2017.



3.2.3 Dry Seasons Comparison In the previous monitoring of emergency pumping of Horseshoe Lake (King County, 2014b and 2016) several parameters– total iron, dissolved aluminum, sulfate, and hardness - were discussed as parameter of interest due to the proximity of the hatchery. Only two wells, MW-10 and MW-12 had total iron concentrations over 300 µg (Table 9). However these concentrations increased from wet season to dry season possibly reflecting the natural variability (Table 4). Dissolved aluminum concentrations were below the detection limit of 2 µg/L for all wells in 2016 and most wells in 2017 except for MW-28 and MW29 which had results of 10.2 and 3.9 µg/L, respectively. A 2016-2017 comparison of total aluminum cannot be done since it was added in 2017. The total aluminum results were much higher compared to the dissolved aluminum results ranging from 2 to 1390 µg/L (Table 4). Like in 2016, the 2017 sulfate results ranged from 1.8 to 3.4 mg/L for 5 in seven wells (Table 10 and Appendix B). Wells MW-10 and MW-28 had results greater than 6 mg/L – 6.5 and 6.7, respectively. All samples were below the secondary standard of 250 mg/L. Hardness results were similar between 2016 and 2017, see Table 11, for four of the six wells. Well MW-12 had lower concentration in 2017 compared to 2016 while site MW-28 had the opposite result (Table 11). As noted previously, it is unknown how much intra-annual variation naturally occurs.



Table 9. Total iron concentration for 2016 and 2017 dry season.

Site Sep-2016 Aug-2017 SEKC_MW-10 2230 743 SEKC_MW-12 619 1590 SEKC_MW-13 dry - no data SEKC_MW-27 1600 54 SEKC_MW-28 180 115 SEKC_MW-29 186 296 SEKC_MW-30 56 190

Units are µg/L = micrograms per liter; Bold results are concentrations greater than the secondary standard of 300 µg/L, Table 3B. Table 10. Sulfate concentrations for 2016 and 2017 dry season.

Site Sep-2016 Aug-2017 SEKC_MW-10 6.5 6.3 SEKC_MW-12 4.7 3.0 SEKC_MW-13 dry - no data SEKC_MW-27 6.3 6.3 SEKC_MW-28 3.3 5.4 SEKC_MW-29 2.1 2.1 SEKC_MW-30 2.4 2.8

Units are mg/L = milligrams per liter. Table 11. Hardness for 2016 and 2017 dry season.

Site Sep-2016 Aug-2017 SEKC_MW-10 74.1 76.6 SEKC_MW-12 41.5 30.8 SEKC_MW-13 dry - no data SEKC_MW-27 55.7 54.4 SEKC_MW-28 53.1 76.1 SEKC_MW-29 22.2 19.6 SEKC_MW-30 29.1 30.4




4.0 SUMMARY This work summarizes groundwater monitoring activities related to the 2017 Horseshoe Lake emergency pumping. Seven monitoring wells were sampled for water quality in April and again in August except for well MW-13; this site goes dry in the summer. No wells had results above the primary drinking water standards (Table 3 and Table 4). Although these wells are not intended for potable use, groundwater water quality results are typically compared to drinking water standards. Bacteria parameters (fecal coliform and Escherichia coli) were added to the list of water quality analytes in 2017 and none were detected at any of these monitoring sites. For some wells, the results of three parameters, total iron, total aluminum, and pH, had values above the secondary drinking water standards – guidelines for aesthetic considerations, such as taste, color, corrosion, and odor. Wells MW-10, MW-12, MW-13 and MW-29 had total iron concentrations greater than the standard of 300 µg/L. Well MW-29 had total aluminum concentrations greater than the standard of 200 µg/L. Lastly, wells MW-27, MW-29 and MW-30 had pH values below the secondary standard of 6.5. All other wells had pH values between 6.5 and 8.5. Well MW-10 is the deepest well sampled and differed from the other wells in regard to the following parameters: higher pH, conductivity, hardness, total alkalinity, and lower dissolved oxygen. These differences infer a deeper, longer groundwater flow path at this site when compared to the other sites sampled. Overall, water quality in 2017 is similar to the previous sampling event in 2016. Any differences, such as dissolved oxygen, conductivity, sulfate and alkalinity may be reflective of seasonal variability; however, additional sampling would be necessary to confirm this range. All sites had lower water levels in summer compared to spring levels similar to published data, Golder, 2013. Only wells, MW-29 and MW-30, show a water level response to the emergency pumping to the infiltration facility. This response is a mounding of water (higher water levels) during active pumping periods.



5.0 REFERENCES Golder Associates. 2013. Technical Memorandum – Reserve at Woodlands Hydrogeologic

Information, King County, Washington. Date: November 13, 2013 Prepared by James Johnson, Golder Associates, Redmond, Washington.

Golder Associates. 2016. Personal communication with Michael Klisch – re: groundwater well information and water level data.

King County. 2004. “Ambient Groundwater Monitoring – 2001-2004 Results.” Prepared by Anchor Environmental and King County Dept. of Natural Resources and Parks, Water and Land Resources Division. Seattle, Washington.

King County. 2014a. Water Quality: 2014 pumping event from Horseshoe Lake to a gravel pit in The Villages proposed development. Prepared by Sally Abella, Water and Land Resources Division. Seattle, Washington.

King County. 2014b. 2014 Horseshoe Lake Emergency Pumping Project - Hydrologic Monitoring. Prepared by David Funke, Water and Land Resources Division. Seattle, Washington.

King County. 2014c. Sampling and Analysis Plan for Sammamish River Valley Groundwater. Prepared by Eric Ferguson and Katherine Bourbonais, Water and Land Resources Division. Seattle, Washington.

King County. 2016a Horseshoe Lake Emergency Pumping Project – Groundwater Monitoring. Prepared by Eric Ferguson, Water and Land Resources Division. Seattle, Washington.

King County. 2016b Personal communication with Rachael Gravon v re: surface water monitoring for Horseshoe Lake emergency pumping.

King County. 2016c. Personal communication with Wes Kameda – re: pumping volumes from Horseshoe Lake.

King County. 2016d. Technical Memo – re: Horseshoe Lake Area Groundwater Monitoring – December 2016. To Wes Kameda from Eric Ferguson.

King County. 2018. Horseshoe Lake Emergency Pumping Project – Surface Water Monitoring 2016 and 2017. Prepared by Rachael Gravon. Water and Land Division. Seattle, Washington.


King County Science and Technical Support Section A-1 May 2018

Appendix A: Water Level Data

As noted in the report, Golder Associates collected hydrologic data for the groundwater monitoring. Golder Associates already had data loggers deployed in five of the seven wells monitored. King County added data loggers in two monitoring wells: MW-12 and MW-28.

No data logger data was available for MW-28 due to the device being removed from well. It is unknown when and who removed equipment.



Table A-1 Depth to Water (manual water level) Measurements. Elevations based on data

presented in Table 1. Golder data was not available at time of publication.

* = depth to water level measurement taken from measuring point; typically top of casing. Unit for depth to water and elevation are feet.

Well id Date/time Depth to water HSL pumping Staff WT-elev4/18/17 10:45 97.89 No King County 483.98/30/17 11:10 104.26 No King County 477.53/22/17 10:10 44.35 No King County 488.64/17/17 9:45 44.75 No King County 488.26/1/17 10:40 47.74 No King County 485.28/29/17 9:25 54.81 No King County 478.1

3/22/17 10:10 35.72 No King County 497.24/17/17 9:40 37.04 No King County 495.86/1/17 10:35 40.85 No King County 492.08/29/17 9:20 -- No King County Dry2/19/17 9:55 43.63 No King County 483.1

4/19/17 10:50 43.61 No King County 483.28/30/17 8:55 47.61 No King County 479.2

3/22/17 11:30 27.75 No King County 482.54/19/17 10:50 28.93 No King County 481.38/30/17 8:55 31.26 No King County 479.0

4/17/17 11:30 53.04 No King County 503.78/31/17 8:55 63.71 No King County 493.14/18/17 9:15 48.66 No King County 504.9

8/29/17 10:55 60.36 No King County 493.2

MW-29

MW-30

MW-10

MW-12

MW-13

MW-27

MW-28



Figure A-2 Comparison of daily Horseshoe Lake Surface Elevation and daily Water Table Elevations of wells MW-10, MW-12, MW-13 and MW-29 for

Water Year 2017. Well MW-13 only had water above the data logger from 2/7 through 8/1/2017. Data collection started on 3/22/2017 for site MW-12. Site MW-29 shows groundwater mounding (peaks in water table elevations) while the lake surface elevation is being pumped down.

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Figure A-3 Water Table Elevation chart for well MW-10 for water year 2017. Data presented are daily values from hourly measurements.

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Figure A-4 Water Table Elevation chart for well MW-12 for water year 2017. Data presented are daily values from hourly measurements. Logger started

3/22/2017.

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Figure A-5 Water Table Elevation chart for well MW-13 for water year 2017. Data presented are daily values from hourly measurements. Well MW-13

only had water above the data logger from 2/7 through 8/1/2017

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Figure A-7 Water Table Elevation chart for well MW-29 for water year 2017. Data presented are daily values from 4-hour measurements.

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King County Science and Technical Support Section B-1 May 2018

Appendix B: Water Quality Data

from 2016 and 2017



Table B-1. Water quality results for site MW-10 from 2016 and 2017.

“*” = refers to parameters not sampled in 2016 and added in 2017. Symbols and abbreviations are the same as Table 4.

Parameter Name Units 2/17/2016 9/29/2016 4/18/2017 8/30/2017Conductivity, Field umhos/cm 169 170 162 162 0.5 10 umhos/cmDissolved Oxygen, Field mg/L 5.1 4.4 5.8 1.3 0.5 1 mg/LpH, Field pH 7.0 7.0 7.2 7.8 0.1 1 pHTemperature, Field deg C 10.7 10.9 10.5 11.3 0.01 0.1 deg CTurbidity, Field NTU 5.0 12.1 4.2 3.2 0.5 2 NTUAluminum, Dissolved ug/L <MDL <MDL <MDL <MDL 2 10 ug/LAluminum, Total* ug/L <MDL 2.2 2 10 ug/LAmmonia Nitrogen mg/L <MDL <MDL <MDL 0.003 0.002 0.01 mg/LAntimony, Dissolved ug/L <MDL <MDL <MDL <MDL 0.3 1 ug/LAntimony, Total* ug/L <MDL <MDL 0.3 1 ug/LArsenic, Dissolved ug/L 0.4 0.4 0.5 0.3 0.1 0.5 ug/LArsenic, Total* ug/L 0.5 0.3 0.1 0.5 ug/LBeryllium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LBeryllium, Total* ug/L <MDL <MDL 0.1 0.5 ug/LCadmium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.05 0.25 ug/LCadmium, Total* ug/L <MDL <MDL 0.05 0.25 ug/LCalcium, Dissolved ug/L 21700 20000 20000 21400 50 50 ug/LCalcium, Total ug/L 21900 21200 20600 22300 50 50 ug/LChromium, Dissolved ug/L 0.4 0.3 0.2 0.3 0.2 1 ug/LChromium, Total* ug/L 0.4 1.1 0.2 1 ug/LCopper, Dissolved ug/L <MDL <MDL <MDL <MDL 0.2 2 ug/LCopper, Total* ug/L <MDL <MDL 0.2 2 ug/LEscherichia coli* CFU/100ml <MDL <MDL 1 CFU/100mlFecal Coliform* CFU/100ml <MDL <MDL 1 CFU/100mlHardness, Calc mg CaCO3/L 79.7 74.1 71.9 76.6 0.33 0.33 mg CaCO3/LIron, Dissolved ug/L 115 59 40 339 10 50 ug/LIron, Total ug/L 822 2230 420 743 10 50 ug/LLead, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LLead, Total* ug/L <MDL <MDL 0.1 0.5 ug/LMagnesium, Dissolved ug/L 5050 4890 4800 4980 50 50 ug/LMagnesium, Total ug/L 6050 5100 5000 5070 50 50 ug/LManganese, Dissolved ug/L 5.2 3.8 3.8 15.9 0.1 0.5 ug/LManganese, Total* ug/L 5.7 22.3 0.1 0.5 ug/LNickel, Dissolved ug/L 0.4 0.3 0.2 0.4 0.1 0.5 ug/LNickel, Total* ug/L 0.3 1.0 0.1 0.5 ug/LNitrite + Nitrate Nitrogen mg/L 0.8 0.9 0.7 0.7 0.01 0.04 mg/LOrthophosphate Phosphorus mg/L 0.009 0.007 0.008 0.004 0.0005 0.002 mg/LSelenium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.5 1 ug/LSelenium, Total* ug/L <MDL <MDL 0.5 1 ug/LSilver, Dissolved ug/L <MDL <MDL <MDL <MDL 0.04 0.2 ug/LSilver, Total* ug/L <MDL <MDL 0.04 0.2 ug/LSulfate mg/L 6.9 6.5 6.5 6.3 0.1 0.2 mg/LThallium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.2 ug/LThallium, Total* ug/L <MDL <MDL 0.1 0.2 ug/LTotal Alkalinity mg CaCO3/L 71.3 69.4 67.7 71.2 1 5 mg CaCO3/LTotal Nitrogen mg/L 0.8 1.0 0.7 0.8 0.05 0.1 mg/LTotal Phosphorus mg/L 0.012 0.011 0.014 0.017 0.005 0.01 mg/LTotal Suspended Solids mg/L 0.5 3.2 0.7 0.7 0.5 1 mg/LZinc, Dissolved ug/L <MDL <MDL <MDL <MDL 0.5 2.5 ug/LZinc, Total* ug/L 1.3 0.6 0.5 2.5 ug/L

MW-10 date

not sampled

not sampled

not sampled

not sampled

MDL RDL Units

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not samplednot samplednot sampled





Parameter Name Units 2/17/2016 9/29/2016 4/17/2017 8/29/2017Conductivity, Field umhos/cm 77 125 69 78 0.5 10 umhos/cmDissolved Oxygen, Field mg/L 10.4 3.8 11.5 8 0.5 1 mg/LpH, Field pH 6.6 6.7 6.7 6.6 0.1 1 pHTemperature, Field deg C 9.5 12 9.6 9.7 0.01 0.1 deg CTurbidity, Field NTU 9.6 5.7 2.8 8.8 0.5 2 NTUAluminum, Dissolved ug/L <MDL <MDL <MDL <MDL 2 10 ug/LAluminum, Total* ug/L 3.0 3.1 2 10 ug/LAmmonia Nitrogen mg/L <MDL <MDL <MDL 0.018 0.002 0.01 mg/LAntimony, Dissolved ug/L <MDL <MDL <MDL <MDL 0.3 1 ug/LAntimony, Total* ug/L <MDL <MDL 0.3 1 ug/LArsenic, Dissolved ug/L 0.2 0.8 0.2 0.3 0.1 0.5 ug/LArsenic, Total* ug/L 0.2 0.3 0.1 0.5 ug/LBeryllium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LBeryllium, Total* ug/L <MDL <MDL 0.1 0.5 ug/LCadmium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.05 0.25 ug/LCadmium, Total* ug/L <MDL <MDL 0.05 0.25 ug/LCalcium, Dissolved ug/L 7030 9180 6220 7270 50 50 ug/LCalcium, Total ug/L 7030 9840 6270 7490 50 50 ug/LChromium, Dissolved ug/L 0.2 <MDL <MDL <MDL 0.2 1 ug/LChromium, Total* ug/L 0.4 0.3 0.2 1 ug/LCopper, Dissolved ug/L <MDL 0.2 <MDL <MDL 0.2 2 ug/LCopper, Total* ug/L <MDL 0.2 0.2 2 ug/LEscherichia coli* CFU/100ml <MDL <MDL 1 CFU/100mlFecal Coliform* CFU/100ml <MDL <MDL 1 CFU/100mlHardness, Calc mg CaCO3/L 31.8 41.5 27.1 30.8 0.331 0.331 mg CaCO3/LIron, Dissolved ug/L 97 19 72 31 10 50 ug/LIron, Total ug/L 1490 619 376 1590 10 50 ug/LLead, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LLead, Total* ug/L <MDL <MDL 0.1 0.5 ug/LMagnesium, Dissolved ug/L 2960 3920 2820 2930 50 50 ug/LMagnesium, Total ug/L 3470 4120 2780 2940 50 50 ug/LManganese, Dissolved ug/L 13.5 1.5 5.2 3.9 0.1 0.5 ug/LManganese, Total* ug/L 8.3 17.6 0.1 0.5 ug/LNickel, Dissolved ug/L 0.2 0.2 0.1 0.2 0.1 0.5 ug/LNickel, Total* ug/L 0.3 0.3 0.1 0.5 ug/LNitrite + Nitrate Nitrogen mg/L 0.8 0.3 0.5 0.6 0.01 0.04 mg/LOrthophosphate Phosphorus mg/L 0.015 0.037 0.010 0.016 0.0005 0.002 mg/LSelenium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.5 1 ug/LSelenium, Total* ug/L <MDL <MDL 0.5 1 ug/LSilver, Dissolved ug/L <MDL <MDL <MDL <MDL 0.04 0.2 ug/LSilver, Total* ug/L <MDL <MDL 0.04 0.2 ug/LSulfate mg/L 2.6 4.7 2.4 3.0 0.1 0.2 mg/LThallium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.2 ug/LThallium, Total* ug/L <MDL <MDL 0.1 0.2 ug/LTotal Alkalinity mg CaCO3/L 29.7 45.2 26.6 31.4 1 5 mg CaCO3/LTotal Nitrogen mg/L 0.80 0.35 0.48 0.58 0.05 0.1 mg/LTotal Phosphorus mg/L 0.019 0.041 0.018 0.023 0.005 0.01 mg/LTotal Suspended Solids mg/L 2.3 1.5 0.7 2.2 0.5 1 mg/LZinc, Dissolved ug/L 0.6 <MDL <MDL <MDL 0.5 2.5 ug/LZinc, Total* ug/L 0.9 0.5 0.5 2.5 ug/L

MW-12 date

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled


not sampled

MDL RDL Units

not sampled

not sampled

not sampled





Parameter Name Units 2/17/2016 9/29/2016 4/17/2017 8/29/2017Conductivity, Field umhos/cm 71.1 68.9 0.5 10 umhos/cmDissolved Oxygen, Field mg/L 11.6 11.3 0.5 1 mg/LpH, Field pH 6.6 6.7 0.1 1 pHTemperature, Field deg C 9.5 9.6 0.01 0.1 deg CTurbidity, Field NTU 0.7 2.3 0.5 2 NTUAluminum, Dissolved ug/L <MDL <MDL 2 10 ug/LAluminum, Total* ug/L not sampled 10 2 10 ug/LAmmonia Nitrogen mg/L <MDL <MDL 0.002 0.01 mg/LAntimony, Dissolved ug/L <MDL <MDL 0.3 1 ug/LAntimony, Total* ug/L not sampled <MDL 0.3 1 ug/LArsenic, Dissolved ug/L 0.1 0.1 0.1 0.5 ug/LArsenic, Total* ug/L not sampled 0.1 0.1 0.5 ug/LBeryllium, Dissolved ug/L <MDL <MDL 0.1 0.5 ug/LBeryllium, Total* ug/L not sampled <MDL 0.1 0.5 ug/LCadmium, Dissolved ug/L <MDL <MDL 0.05 0.25 ug/LCadmium, Total* ug/L not sampled <MDL 0.05 0.25 ug/LCalcium, Dissolved ug/L 6400 6180 50 50 ug/LCalcium, Total ug/L 6620 6310 50 50 ug/LChromium, Dissolved ug/L 0.2 <MDL 0.2 1 ug/LChromium, Total* ug/L not sampled 0.4 0.2 1 ug/LCopper, Dissolved ug/L <MDL 0.4 0.2 2 ug/LCopper, Total* ug/L not sampled 0.7 0.2 2 ug/LEscherichia coli* CFU/100ml not sampled <MDL 1 CFU/100mlFecal Coliform* CFU/100ml not sampled <MDL 1 CFU/100mlHardness, Calc mg CaCO3/L 30.9 27.5 0.331 0.331 mg CaCO3/LIron, Dissolved ug/L <MDL <MDL 10 50 ug/LIron, Total ug/L 16 460 10 50 ug/LLead, Dissolved ug/L <MDL <MDL 0.1 0.5 ug/LLead, Total* ug/L not sampled <MDL 0.1 0.5 ug/LMagnesium, Dissolved ug/L 2910 2890 50 50 ug/LMagnesium, Total ug/L 3500 2860 50 50 ug/LManganese, Dissolved ug/L 0.2 0.8 0.1 0.5 ug/LManganese, Total* ug/L not sampled 3.4 0.1 0.5 ug/LNickel, Dissolved ug/L 0.1 0.2 0.1 0.5 ug/LNickel, Total* ug/L not sampled 0.5 0.1 0.5 ug/LNitrite + Nitrate Nitrogen mg/L 0.5 0.4 0.01 0.04 mg/LOrthophosphate Phosphorus mg/L 0.014 0.011 0.0005 0.002 mg/LSelenium, Dissolved ug/L <MDL <MDL 0.5 1 ug/LSelenium, Total* ug/L not sampled <MDL 0.5 1 ug/LSilver, Dissolved ug/L <MDL <MDL 0.04 0.2 ug/LSilver, Total* ug/L not sampled <MDL 0.04 0.2 ug/LSulfate mg/L 2.6 2.5 0.1 0.2 mg/LThallium, Dissolved ug/L <MDL <MDL 0.1 0.2 ug/LThallium, Total* ug/L not sampled <MDL 0.1 0.2 ug/LTotal Alkalinity mg CaCO3/L 28.9 26.8 1 5 mg CaCO3/LTotal Nitrogen mg/L 0.5 0.4 0.05 0.1 mg/LTotal Phosphorus mg/L 0.014 0.016 0.005 0.01 mg/LTotal Suspended Solids mg/L <MDL 0.7 0.5 1 mg/LZinc, Dissolved ug/L <MDL <MDL 0.5 2.5 ug/LZinc, Total* ug/L not sampled 0.5 0.5 2.5 ug/L

MDL RDL Units

Not sampled - dry

well

MW-13 date

Not sampled - dry

well





Parameter Name Units 3/2/2016 9/28/2016 4/19/2017 8/30/2017Conductivity, Field umhos/cm 99.8 128 85.6 128 0.5 10 umhos/cmDissolved Oxygen, Field mg/L 10.3 6.5 9.9 6 0.5 1 mg/LpH, Field pH 6.5 6.5 6.4 6.5 0.1 1 pHTemperature, Field deg C 10.1 10.9 9.7 10.7 0.01 0.1 deg CTurbidity, Field NTU 2.1 27.8 2.6 1.7 0.5 2 NTUAluminum, Dissolved ug/L <MDL <MDL <MDL <MDL 2 10 ug/LAluminum, Total* ug/L 70 50 2 10 ug/LAmmonia Nitrogen mg/L <MDL <MDL <MDL <MDL 0.002 0.01 mg/LAntimony, Dissolved ug/L <MDL <MDL <MDL <MDL 0.3 1 ug/LAntimony, Total* ug/L <MDL <MDL 0.3 1 ug/LArsenic, Dissolved ug/L 0.2 0.2 0.2 0.2 0.1 0.5 ug/LArsenic, Total* ug/L 0.2 0.2 0.1 0.5 ug/LBeryllium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LBeryllium, Total* ug/L <MDL <MDL 0.1 0.5 ug/LCadmium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.05 0.25 ug/LCadmium, Total* ug/L <MDL <MDL 0.05 0.25 ug/LCalcium, Dissolved ug/L 9140 13000 8320 14100 50 50 ug/LCalcium, Total ug/L 8870 14100 8350 14400 50 50 ug/LChromium, Dissolved ug/L 0.2 0.3 0.2 0.3 0.2 1 ug/LChromium, Total* ug/L 0.5 0.5 0.2 1 ug/LCopper, Dissolved ug/L 0.2 <MDL 0.3 0.4 0.2 2 ug/LCopper, Total* ug/L 0.5 0.4 0.2 2 ug/LEscherichia coli* CFU/100ml <MDL <MDL 1 CFU/100mlFecal Coliform* CFU/100ml <MDL <MDL 1 CFU/100mlHardness, Calc mg CaCO3/L 37.3 55.7 32.6 54.4 0.33 0.33 mg CaCO3/LIron, Dissolved ug/L <MDL <MDL <MDL <MDL 10 50 ug/LIron, Total ug/L 93 1600 70 54 10 50 ug/LLead, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LLead, Total* ug/L <MDL <MDL 0.1 0.5 ug/LMagnesium, Dissolved ug/L 3280 4300 2900 4390 50 50 ug/LMagnesium, Total ug/L 3680 5010 2860 4490 50 50 ug/LManganese, Dissolved ug/L 2.93 6.6 0.7 1.0 0.1 0.5 ug/LManganese, Total* ug/L 2.6 2.2 0.1 0.5 ug/LNickel, Dissolved ug/L 0.3 0.3 0.2 0.3 0.1 0.5 ug/LNickel, Total* ug/L 0.5 0.4 0.1 0.5 ug/LNitrite + Nitrate Nitrogen mg/L 2.2 0.9 1.9 0.9 0.01 0.04 mg/LOrthophosphate Phosphorus mg/L 0.007 0.008 0.006 0.007 0.0005 0.002 mg/LSelenium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.5 1 ug/LSelenium, Total* ug/L <MDL <MDL 0.5 1 ug/LSilver, Dissolved ug/L <MDL <MDL <MDL <MDL 0.04 0.2 ug/LSilver, Total* ug/L <MDL <MDL 0.04 0.2 ug/LSulfate mg/L 3.7 6.3 3.4 6.3 0.1 0.2 mg/LThallium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.2 ug/LThallium, Total* ug/L <MDL <MDL 0.1 0.2 ug/LTotal Alkalinity mg CaCO3/L 34.6 48.5 27.1 49.5 1 5 mg CaCO3/LTotal Nitrogen mg/L 2.3 0.9 1.8 1.0 0.05 0.1 mg/LTotal Phosphorus mg/L 0.012 0.038 0.011 0.010 0.005 0.01 mg/LTotal Suspended Solids mg/L <MDL 26.3 0.9 0.6 0.5 1 mg/LZinc, Dissolved ug/L 0.7 <MDL <MDL 0.9 0.5 2.5 ug/LZinc, Total* ug/L 1.0 <MDL 0.5 2.5 ug/L

MW-27 date

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled


not sampled

MDL RDL Units

not sampled

not sampled

not sampled





Parameter Name Units 3/2/2016 9/28/2016 4/19/2017 8/30/2017Conductivity, Field umhos/cm 144 118 153 145 0.5 10 umhos/cmDissolved Oxygen, Field mg/L 8.3 7.7 7.7 8.1 0.5 1 mg/LpH, Field pH 6.7 6.6 6.8 6.7 0.1 1 pHTemperature, Field deg C 10.1 10.4 10.0 10.1 0.01 0.1 deg CTurbidity, Field NTU 3.7 3.5 3.1 1.8 0.5 2 NTUAluminum, Dissolved ug/L <MDL <MDL 10.2 <MDL 2 10 ug/LAluminum, Total* ug/L 102 98 2 10 ug/LAmmonia Nitrogen mg/L 0.013 <MDL <MDL <MDL 0.002 0.01 mg/LAntimony, Dissolved ug/L <MDL <MDL <MDL <MDL 0.3 1 ug/LAntimony, Total* ug/L <MDL <MDL 0.3 1 ug/LArsenic, Dissolved ug/L 0.3 0.4 0.4 0.3 0.1 0.5 ug/LArsenic, Total* ug/L 0.4 0.4 0.1 0.5 ug/LBeryllium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LBeryllium, Total* ug/L <MDL <MDL 0.1 0.5 ug/LCadmium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.05 0.25 ug/LCadmium, Total* ug/L <MDL <MDL 0.05 0.25 ug/LCalcium, Dissolved ug/L 16900 13000 18000 17400 50 50 ug/LCalcium, Total ug/L 16100 14700 18200 21400 50 50 ug/LChromium, Dissolved ug/L 0.4 0.3 0.5 0.4 0.2 1 ug/LChromium, Total* ug/L 1.1 0.8 0.2 1 ug/LCopper, Dissolved ug/L <MDL <MDL 0.6 0.2 0.2 2 ug/LCopper, Total* ug/L 0.6 0.5 0.2 2 ug/LEscherichia coli* CFU/100ml <MDL <MDL 1 CFU/100mlFecal Coliform* CFU/100ml <MDL <MDL 1 CFU/100mlHardness, Calc mg CaCO3/L 61.0 53.1 66.1 76.1 0.33 0.33 mg CaCO3/LIron, Dissolved ug/L <MDL <MDL 11 <MDL 10 50 ug/LIron, Total ug/L 239 180 117 115 10 50 ug/LLead, Dissolved ug/L <MDL <MDL 0.18 <MDL 0.1 0.5 ug/LLead, Total* ug/L <MDL <MDL 0.1 0.5 ug/LMagnesium, Dissolved ug/L 4250 3540 4760 4510 50 50 ug/LMagnesium, Total ug/L 5080 4000 5020 5520 50 50 ug/LManganese, Dissolved ug/L <MDL <MDL 0.6 <MDL 0.1 0.5 ug/LManganese, Total* ug/L 5.3 4.9 0.1 0.5 ug/LNickel, Dissolved ug/L 0.2 0.2 0.5 0.2 0.1 0.5 ug/LNickel, Total* ug/L 0.8 0.5 0.1 0.5 ug/LNitrite + Nitrate Nitrogen mg/L 1.8 0.8 1.4 2.1 0.01 0.04 mg/LOrthophosphate Phosphorus mg/L 0.007 0.009 0.008 0.008 0.0005 0.002 mg/LSelenium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.5 1 ug/LSelenium, Total* ug/L <MDL <MDL 0.5 1 ug/LSilver, Dissolved ug/L <MDL <MDL <MDL <MDL 0.04 0.2 ug/LSilver, Total* ug/L <MDL <MDL 0.04 0.2 ug/LSulfate mg/L 6.1 3.3 6.7 5.4 0.1 0.2 mg/LThallium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.2 ug/LThallium, Total* ug/L <MDL <MDL 0.1 0.2 ug/LTotal Alkalinity mg CaCO3/L 54.7 48.3 60.0 55.2 1 5 mg CaCO3/LTotal Nitrogen mg/L 1.9 0.8 1.3 2.2 0.05 0.1 mg/LTotal Phosphorus mg/L 0.015 0.014 0.013 0.012 0.005 0.01 mg/LTotal Suspended Solids mg/L 1.8 1.9 1.2 1.0 0.5 1 mg/LZinc, Dissolved ug/L <MDL <MDL 2.55 <MDL 0.5 2.5 ug/LZinc, Total* ug/L 1.0 <MDL 0.5 2.5 ug/L

MW-28 date

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled


not sampled

MDL RDL Units

not sampled

not sampled

not sampled





Parameter Name Units 3/3/2016 10/6/2016 4/17/2017 8/31/2017Conductivity, Field umhos/cm 62.8 65.9 49.1 55.1 0.5 10 umhos/cmDissolved Oxygen, Field mg/L 11.4 10.1 11.4 10.4 0.5 1 mg/LpH, Field pH 6.1 6.0 6.0 6.2 0.1 1 pHTemperature, Field deg C 10.5 14 9.7 11 0.01 0.1 deg CTurbidity, Field NTU 38.1 5.1 10 2.2 0.5 2 NTUAluminum, Dissolved ug/L <MDL <MDL 3.9 <MDL 2 10 ug/LAluminum, Total* ug/L 1390 465 2 10 ug/LAmmonia Nitrogen mg/L 0.011 0.003 <MDL <MDL 0.002 0.01 mg/LAntimony, Dissolved ug/L <MDL <MDL <MDL <MDL 0.3 1 ug/LAntimony, Total* ug/L <MDL <MDL 0.3 1 ug/LArsenic, Dissolved ug/L <MDL 0.1 <MDL 0.1 0.1 0.5 ug/LArsenic, Total* ug/L 0.4 0.2 0.1 0.5 ug/LBeryllium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LBeryllium, Total* ug/L <MDL <MDL 0.1 0.5 ug/LCadmium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.05 0.25 ug/LCadmium, Total* ug/L <MDL <MDL 0.05 0.25 ug/LCalcium, Dissolved ug/L 5750 5840 4380 5250 50 50 ug/LCalcium, Total ug/L 6860 6160 4690 5500 50 50 ug/LChromium, Dissolved ug/L 0.4 0.4 0.4 0.3 0.2 1 ug/LChromium, Total* ug/L 2.8 1.2 0.2 1 ug/LCopper, Dissolved ug/L <MDL 0.3 0.3 <MDL 0.2 2 ug/LCopper, Total* ug/L 2.7 0.9 0.2 2 ug/LEscherichia coli* CFU/100ml <MDL <MDL 1 CFU/100mlFecal Coliform* CFU/100ml <MDL <MDL 1 CFU/100mlHardness, Calc mg CaCO3/L 28.8 22.2 17.8 19.6 0.33 0.33 mg CaCO3/LIron, Dissolved ug/L <MDL <MDL <MDL <MDL 10 50 ug/LIron, Total ug/L 5470 186 865 296 10 50 ug/LLead, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LLead, Total* ug/L 0.27 0.13 0.1 0.5 ug/LMagnesium, Dissolved ug/L 1510 1630 1210 1350 50 50 ug/LMagnesium, Total ug/L 2840 1660 1470 1420 50 50 ug/LManganese, Dissolved ug/L 0.9 1.4 0.6 0.4 0.1 0.5 ug/LManganese, Total* ug/L 27.5 10.5 0.1 0.5 ug/LNickel, Dissolved ug/L 0.2 0.8 0.6 0.2 0.1 0.5 ug/LNickel, Total* ug/L 2.7 1.0 0.1 0.5 ug/LNitrite + Nitrate Nitrogen mg/L 2.7 1.4 1.7 1.1 0.01 0.04 mg/LOrthophosphate Phosphorus mg/L 0.006 0.010 0.005 0.010 0.0005 0.002 mg/LSelenium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.5 1 ug/LSelenium, Total* ug/L <MDL <MDL 0.5 1 ug/LSilver, Dissolved ug/L <MDL <MDL <MDL <MDL 0.04 0.2 ug/LSilver, Total* ug/L <MDL <MDL 0.04 0.2 ug/LSulfate mg/L 1.8 2.1 1.7 2.1 0.1 0.2 mg/LThallium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.2 ug/LThallium, Total* ug/L <MDL <MDL 0.1 0.2 ug/LTotal Alkalinity mg CaCO3/L 15.2 19.7 11.4 16.6 1 5 mg CaCO3/LTotal Nitrogen mg/L 2.7 1.6 1.8 1.1 0.05 0.1 mg/LTotal Phosphorus mg/L 0.092 0.015 0.029 0.018 0.005 0.01 mg/LTotal Suspended Solids mg/L 178 4 30 7 0.5 1 mg/LZinc, Dissolved ug/L <MDL <MDL 0.95 <MDL 0.5 2.5 ug/LZinc, Total* ug/L 2.5 1.6 0.5 2.5 ug/L

MW-29 date

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled


not sampled

MDL RDL Units

not sampled

not sampled

not sampled





Parameter Name Units 3/10/2016 9/26/2016 4/18/2017 8/29/2017Conductivity, Field umhos/cm 83.9 96 72.3 77.8 0.5 10 umhos/cmDissolved Oxygen, Field mg/L 8.5 7 10.6 8.1 0.5 1 mg/LpH, Field pH 6.5 6.6 6.4 6.4 0.1 1 pHTemperature, Field deg C 10.9 12.4 10.7 13.1 0.01 0.1 deg CTurbidity, Field NTU 11.9 1.5 2.9 8.6 0.5 2 NTUAluminum, Dissolved ug/L <MDL <MDL <MDL <MDL 2 10 ug/LAluminum, Total* ug/L 118 109 2 10 ug/LAmmonia Nitrogen mg/L <MDL <MDL <MDL <MDL 0.002 0.01 mg/LAntimony, Dissolved ug/L <MDL <MDL <MDL <MDL 0.3 1 ug/LAntimony, Total* ug/L <MDL <MDL 0.3 1 ug/LArsenic, Dissolved ug/L 0.2 0.2 0.1 0.2 0.1 0.5 ug/LArsenic, Total* ug/L 0.2 0.2 0.1 0.5 ug/LBeryllium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LBeryllium, Total* ug/L <MDL <MDL 0.1 0.5 ug/LCadmium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.05 0.25 ug/LCadmium, Total* ug/L <MDL <MDL 0.05 0.25 ug/LCalcium, Dissolved ug/L 6130 5660 5380 6040 50 50 ug/LCalcium, Total ug/L 6180 5840 5480 6270 50 50 ug/LChromium, Dissolved ug/L 0.5 0.4 0.4 0.7 0.2 1 ug/LChromium, Total* ug/L 0.9 2.1 0.2 1 ug/LCopper, Dissolved ug/L 0.3 0.8 0.4 0.3 0.2 2 ug/LCopper, Total* ug/L 0.6 0.4 0.2 2 ug/LEscherichia coli* CFU/100ml <MDL <MDL 1 CFU/100mlFecal Coliform* CFU/100ml <MDL <MDL 1 CFU/100mlHardness, Calc mg CaCO3/L 31.6 29.1 27.2 30.4 0.33 0.33 mg CaCO3/LIron, Dissolved ug/L 41 12 <MDL 59 10 50 ug/LIron, Total ug/L 598 56 134 190 10 50 ug/LLead, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.5 ug/LLead, Total* ug/L <MDL <MDL 0.1 0.5 ug/LMagnesium, Dissolved ug/L 3580 3410 3120 3510 50 50 ug/LMagnesium, Total ug/L 3930 3530 3280 3570 50 50 ug/LManganese, Dissolved ug/L 20.9 7.2 6.6 29.4 0.1 0.5 ug/LManganese, Total* ug/L 11.1 32.9 0.1 0.5 ug/LNickel, Dissolved ug/L 2.1 1.1 0.8 1.5 0.1 0.5 ug/LNickel, Total* ug/L 1.2 2.3 0.1 0.5 ug/LNitrite + Nitrate Nitrogen mg/L 2.8 2.8 2.4 1.7 0.01 0.04 mg/LOrthophosphate Phosphorus mg/L 0.003 0.005 0.003 0.003 0.0005 0.002 mg/LSelenium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.5 1 ug/LSelenium, Total* ug/L <MDL <MDL 0.5 1 ug/LSilver, Dissolved ug/L <MDL <MDL <MDL <MDL 0.04 0.2 ug/LSilver, Total* ug/L <MDL <MDL 0.04 0.2 ug/LSulfate mg/L 3.4 2.4 2.4 2.8 0.1 0.2 mg/LThallium, Dissolved ug/L <MDL <MDL <MDL <MDL 0.1 0.2 ug/LThallium, Total* ug/L <MDL <MDL 0.1 0.2 ug/LTotal Alkalinity mg CaCO3/L 23.7 21.3 19.8 25.2 1 5 mg CaCO3/LTotal Nitrogen mg/L 2.9 2.9 2.3 1.8 0.05 0.1 mg/LTotal Phosphorus mg/L 0.022 0.009 0.011 0.014 0.005 0.01 mg/LTotal Suspended Solids mg/L 27.8 1.4 5.0 4.6 0.5 1 mg/LZinc, Dissolved ug/L 0.5 0.7 <MDL <MDL 0.5 2.5 ug/LZinc, Total* ug/L 0.9 0.5 0.5 2.5 ug/L

MW-30 date

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled

not sampled


not sampled

MDL RDL Units

not sampled

not sampled

not sampled

Documents

2017 Horseshoe Lake Emergency Pumping Groundwater …...2017 Horseshoe Lake Emergency Pumping – Groundwater Monitoring King County Science and Technical Support Section v May 2018