Client: Arizona Water Company
Dates: Oct. 2014 – Dec. 2014
Tasks: Hydrologic Study and Modification of PAD
Project Description: SGC was contracted by Arizona Water Company (AWC) to conduct a Hydrologic Study supporting the Modification of the Physical Availability Determination (PAD) application for the Superstition Water System (AWC-Superstition) located in the East Salt River Valley (ESRV) Sub-basin of the Phoenix Active Management Area (AMA). The long-term 100-year impact on the aquifer due to the projected groundwater pumping for AWC-Superstition was estimated using the numerical Regional Ground-water Flow Model of the Salt River Valley (SRV83-06v3) (ADWR, 2014). For this study, SGC refined and recalibrated the SRV Model in and around the AWC-Superstition Certificate of Convenience and Necessity (CCN) area. Conservatively assuming that AWC-Superstition’s entire water demand would be met by pumped groundwater, simulated depths to groundwater beneath AWC-Superstition after 100 years of pumping current, committed, and approved demands were less than the 1,000 ft bls depth to groundwater limit established for water providers inside the Phoenix AMA by ADWR Rule R12-15-716. Based on this impact analysis, SGC demonstrated that sufficient groundwater is available in the underlying regional aquifer to meet the water demands of AWC-Superstition for 100 years.
Client: City of Eloy
Dates: Feb. 2012 – Apr. 2013
Tasks: Well Siting Study
Project Description: SGC conducted a well siting investigation for the City of Eloy in the vicinity of the existing water production and distribution system north of I-10 between La Palma Road and Sunland-Gin Road. The siting criteria were:
The above criteria were used to identify portions of the Study Area suitable for a municipal water supply well. The initial screening criteria (Hydrogeologic Conditions and Environmental Hazards) were used to identify potential sites. Those areas were further refined based on City owned properties meeting minimal size requirements as well as being a reasonable distance to existing infrastructure. Once parcels were identified that met the hydrogeologic, environmental, infrastructure, and City ownership requirements, ADWR Well Spacing rules were applied to those sites in order to estimate yield.
Subsequent investigations were conducted to further evaluate the most promising wells. The goal of the evaluation process was to identify which well or wells were in the best physical condition, produced the best water quality, and pumped at a rate that would be useful to the City.
Client: HDR Engineering, Inc.
Dates: Jan. 2014 – July 2014
Tasks: Vadose zone well installation and testing
Project Description: SGC was contracted by HDR Engineering to provide professional services for the drilling and installation of a test vadose zone well at the City of Peoria’s Butler Water Reclamation Facility (WRF). The Butler WRF is located in the West Salt River sub-basin of the Phoenix Active Management Area. The purpose of the test well was to evaluate the subsurface conditions and provide a basis for location and design of future vadose zone recharge wells.
SGC documented drilling of the test borehole which was drilled using a sonic drill rig to continuously core the vadose zone beneath the Butler WRF to approximately 227 feet below land surface (ft bls). Lithologic samples were extracted from a 6-inch core barrel and placed in plastic sleeves every 2.5-ft. SGC inspected the sonic core samples for the presence of fine sediments, particularly silt and clay, which could potentially impede the infiltration of recharge water. SGC prepared a lithologic log, designed, and oversaw construction of the test well which was completed in the vadose (unsaturated) zone to a depth of 180 ft bls using 6-inch Schedule 40 PVC casing.
Using potable water from a fire hydrant, a 13-day injection test was conducted in the test well. SGC collected and analyzed the test data to evaluate the future potential of large diameter vadose zone recharge wells at the Butler WRF site.
Client: City of Chandler
Dates: Mar. 2013 – Oct. 2013
Tasks: ASR well testing and performance
Project Description: The City of Chandler uses ASR wells to help manage reclaimed water and support their overall water portfolio. The City retained SGC to develop an ASR Well Testing Program to evaluate recharge well performance at the Tumbleweed and Ocotillo Recharge Facilities. SGC initially reviewed operational data from 14 ASR wells over a 36 month period. Variations in individual well performance were observed. Subsequent testing was undertaken to 1) Evaluate potential causes for the differences in well performance, and 2) Estimate the maximum recharge capacity of each ASR well.
In order to accomplish these goals, the following tasks were performed at each ASR well:
Results of the ASR Well Testing Program included the following recommendations:
Client: City of Tempe
Dates: Dec. 2014 – May 2015
Tasks: Well installation and testing
Project Description SGC was contracted by Wilson Engineers, LLC to permit and provide professional oversight services for drilling and installation of City of Tempe Well #16 which was to be located near a busy street in close proximity to existing commercial, retail, and residential development. SGC hydrogeologists provided construction oversight, documented all drilling and testing operations and determined the optimal screen and filter pack design following analysis of drill cuttings, downhole geophysical logs, and zonal water quality samples. The challenge in designing this well was to avoid portions of the aquifer having elevated concentrations of arsenic. In addition, sound barriers were utilized and dust control measures implemented to minimize the impact of well construction and testing activities on nearby businesses and residents. Step-rate and constant-rate discharge testing at rates of 3,600 to 4,000 gallons per minute (gpm) resulted in minimal water level drawdown. The quality of groundwater pumped from the newly installed production well met safe drinking water standards for primary Maximum Contaminant Levels (MCLs) for all constituents analyzed.
Client: Navajo Tribal Utility Authority (NTUA)
Dates: Aug. 2010 – Dec. 2011
Tasks: Evaluate the condition of 250+ wells
Project Description: SGC collected available well data from multiple sources in order to evaluate the condition of over 250 NTUA wells in seven districts (Chinle, Crownpoint, Dilcon, Fort Defiance, Kayenta, Shiprock, and Tuba City) spanning portions of Arizona, New Mexico, and Utah. Key work products included: well summary data sheets (WSDS) for each NTUA well, updating and expansion of well information into a single table of NTUA wells, and preparation of a flow chart to assist in the evaluation of the condition of the wells. SGC developed the Specific Capacity Monitoring Program (SCMP) in order to provide NTUA staff with a quick method to help identify potential well production problems.
The well data are presented in a 20-volume report entitled “Report of Wells” that contains key portions of the data reviewed from the various well sources. The report will assist NTUA staff in evaluating the condition of the wells and determining when wells may need rehabilitation, where additional data are needed to better evaluate the wells, and/or if the aquifer system can or cannot support any additional wells in the well field.
Client: Water Works Engineers
Dates: Jan. – Apr. 2013
Tasks: Well Installation and Testing
Project Description: SGC was sub-contracted by Water Works Engineers to oversee the drilling, installation, and testing of a new well for the Twin Arrows Navajo Casino Resort in Flagstaff, Arizona. The well was successfully drilled to approximately 1,200 feet and is used to supplement drinking water supplies to the resort.
The well was completed in the Coconino Sandstone of the C-Aquifer. SGC personnel provided oversight of daily drilling activities, well construction, well development, and aquifer testing. SGC personnel also provided oversight of the geophysical logging, and collected water quality samples from the well.
Data collected during the aquifer testing was used to estimate hydrologic characteristics of the aquifer including transmissivity. A final well installation report was prepared which included recommendations for the permanent pump setting depth, and long-term pumping rate.
Client: City of Chandler
Dates: June 2005 – Dec. 2014
Tasks: Well installation and testing
Project Description: SGC was retained by the City of Chandler Public Works Department to provide production well testing, and construction management services for seven (7) high capacity municipal water supply wells. SGC hydrogeologists inspected all drilling and testing operations and finalized screen locations following analysis of drill cuttings, downhole geophysical logs, and zonal water quality samples. The most critical objectives were to minimize the concentrations of undesirable water quality constituents while maintaining the production design criteria. Water quality results at one of the wells prompted studies to identify zones producing elevated concentrations of nitrate. The remedial investigation and design included: spinner logging, packer tests, and cementing off portions of the well screen. All seven wells were successfully completed.
Client: City of Prescott
Tasks: Water supply study, Groundwater flow modeling
Project Description: Hydrogeologic studies and groundwater numerical modeling were conducted in support of the City of Prescott’s acquisition of the Big Chino Water Ranch and the withdrawal of groundwater under A.R.S. 45-555. Study focused on the hydrogeology of the Big Chino Ranch and Upper Big Chino sub-basin and the movement of groundwater into, through, and out of this area. The study included the following major tasks:
Due to the controversial nature of the planned groundwater withdrawals, the study and groundwater model were subjected to extensive review by ADWR. Following this review the analysis and model were approved by ADWR. On appeal, the model and analysis were upheld.
Client: City of Flagstaff
Dates: June 2013 – Dec 2015
Tasks: Groundwater flow modeling to assess the impact of pumping on streamflow
Project Description: SGC was contracted by the City of Flagstaff to conduct a detailed groundwater modeling study for the Red Gap Ranch Water Resources Environmental Assessment Services (Project No. 524900). SGC modified a version of the Northern Arizona Regional Groundwater Flow Model (NARGFM; Pool, et al., 2011) to assess the impact of pumping groundwater from proposed well fields on base flow in perennial reaches of tributaries to the Little Colorado River.
Client: Iota Violet, LLC
Dates: Dec. 2014 – Feb. 2015
Tasks: Groundwater modeling, hydrogeologic report, 2 AAWS applications
Project Description: SGC was contracted by Iota Violet, LLC to complete a Hydrogeologic Report and two Analyses of Assured Water Supply (AAWS) for two properties (the Projects) consisting of 352-acre and 71-acre properties located in the Maricopa-Stanfield Sub-basin of the Pinal Active Management Area (AMA). The long-term 100-year impact on the aquifer due to projected groundwater pumping for the Projects was estimated using the numerical Regional Groundwater Flow Model of the Pinal AMA (Pinal Model) (Liu et.al, 2014). ADWR recently released the Pinal AMA Groundwater Model Projections out to 2115 (Yunker, 2014), which was built upon the Pinal Model. Thirteen scenarios were run to test and improve the model. Model scenario #13 was provided by ADWR to serve as the base 100-year predictive model scenario for new Assured Water Supply applicants. SGC recently updated this Model scenario #13 in support of Assured Water Supply approvals in the Pinal AMA.
Client: Pinal Land Holdings/Farm Sources International
Dates: May 2013 – Apr. 2014
Tasks: Groundwater modeling, AAWS application
Project Description: SGC was contracted by Pinal Land Holdings to prepare an Application for Analysis of Assured Water Supply (AAWS) for review and approval by ADWR. The Mesa Farms property (the Project) is located in the Eloy Sub-basin of the Pinal Active Management Area (AMA). The application covered approximately 11,500 acres of historically farmed land and desert land, and required the development of a detailed groundwater flow model to evaluate the impact of development and to project future 100-year water levels to meet ADWR standards. The base model for this analysis was a calibrated regional model (Florence Model) developed by SGC. The model was recalibrated to local groundwater levels to provide a more precise simulation of groundwater levels. This modeling effort required extensive hydrogeologic evaluation and close interaction with ADWR staff. The application was reviewed and approved by ADWR.
Client: Multiple land owners
Dates: June 2003 – June 2010
Tasks: AAWS applications for multiple owners
Project Description: SGC was retained by several land owners of master planned communities in the City of Buckeye to prepare hydrogeologic studies documenting available groundwater resources and to prepare Applications for Analyses of Assured Water Supply (AAWS). The communities included Cipriani, Douglas Ranch, Park Regional Center, Tartesso, and Trillium. Analytical aquifer impact models were used for successful approvals for several of the projects. SGC then represented land owners as stakeholders in the development of the Lower Hassayampa Groundwater Flow Model that was intended for use in support of future Assured Water Supply approvals and the management of the groundwater resources for the City of Buckeye. Following release of the Hassayampa Model, SGC updated it with demands associated with AWS approvals subsequent to the original model development, and used the updated version for successful approval of the AAWS for the Park Regional Center. SGC also prepared multiple modeling scenarios with the updated model for potential use towards new AAWS applications.
Client: Iota Rodeo Road, LLC
Dates: Oct. – Nov. 2014
Tasks: Hydrogeologic Report using the new ADWR Pinal Model (Yunker, 2014) and two AAWS applications
Project Description: SGC was contracted by Iota Rodeo Road, LLC to complete a Hydrogeologic Report and two Analyses of Assured Water Supply (AAWS) for two properties (the Projects) consisting of 146-acre and 136-acre properties located in the Eloy Sub-basin of the Pinal Active Management Area (AMA). The long-term 100-year impact on the aquifer due to projected groundwater pumping for the Projects was estimated using the numerical Regional Groundwater Flow Model of the Pinal AMA (Pinal Model) (Liu et.al, 2014). ADWR recently released the Pinal AMA Groundwater Model Projections out to 2115 (Yunker, 2014), which was built upon the Pinal Model. Thirteen scenarios were run to test and improve the model. Model scenario #13 was provided by ADWR to serve as the base 100-year predictive model scenario for new Assured Water Supply applicants. SGC recently updated this Model scenario #13 in support of Assured Water Supply approvals in the Pinal AMA.
Client: EnviroIntegration Services, LLC
Dates: Sept. 2011 – June 2012
Tasks: APP Significant Amendment Application
Project Description: As a subcontractor to EnviroIntegration Services, SGC performed hydrogeologic characterization and analysis in support of an Aquifer Protection Permit (APP) application for the Oracle Ridge Mine which is located in the Santa Catalina Mountains north of Tucson, Arizona. SGC prepared the APP application, which addressed the five basic demonstrations:
An in-depth hydrologic demonstration was performed. This included installation of new monitoring wells, development of hydrographs, contour maps, and cross-sections, water quality sampling and aquifer testing. SGC personnel conducted hydrologic testing of facility wells, reviewed, tabulated, and summarized the data. Groundwater characteristics at the facility were determined including the depth, flow rate, flow direction, quantity of flow and quality of groundwater.
SGC developed a hydrogeologic conceptual model and a numerical flow and transport model to determine the Discharge Impact Area (DIA) for the tailings facility. The model was calibrated to historical conditions including past geochemical changes down-gradient of the existing tailings facility.
Client: Water Works Engineers, LLC
Dates: Nov. 2009 – December 2011
Tasks: Modification of DAWS
Project Description: Working as a subcontractor to Water Works Engineers, SGC prepared a detailed hydrogeologic report in order to satisfy the demonstration of physical availability of groundwater in support of a Modification of a DAWS for the Town of Florence (ADWR No. 26-401284.0000). The hydrologic report demonstrates the physical availability of groundwater to Florence for 100 years using historic and existing hydrologic data in conjunction with current groundwater models developed for the region. SGC prepared the Application for a Modification of a Designation of Assured Water Supply on behalf of the Town of Florence and submitted it to ADWR for approval.
Client: Baseline Construction, Inc.
Dates: March – June 2013
Tasks: Phase I and Phase II Environmental Site Assessments (ESAs)
Project Description: SGC was contracted by the developer for a national retailer to conduct a Phase I ESA on a multiple parcel site that was previously developed with an automobile dealership and motel. Through numerous additions and upgrades over the 50 year development history, a number of environmental issues had developed. SGC identified seven recognized environmental conditions related to USTs, sumps, hydraulic lifts, hazardous waste storage areas and surface staining. Through a Phase II Environmental Assessment of the site, SGC was able to resolve each of the recognized environmental conditions. This work was conducted on an accelerated schedule to accommodate the rigorous deadlines associated with a commercial real estate transaction. The Phase II ESA required innovative drilling and sampling approaches to collect data within buildings. Analytical programs were optimized to assess target analytes consistent with the previous development and to reduce laboratory costs. SGC utilized data from 17 borings and 31 samples in the Phase II ESA. Results of the Phase II ESA indicated that the features associated with the previous development would not require additional investigation or remediation.
Client: Arizona Department of Environmental Quality (ADEQ)
Dates: July 2008 – June 2009
Tasks: Modified Phase II Environmental Site Assessment (ESA)
Project Description: SGC was contracted by ADEQ to conduct a Modified Phase II ESA to assess the extent of contamination due to historical operations at Special Planning Area #1 Water Reclamation Facility, Surprise, Arizona (SCC Contract No. 060000-A4-3, ADEQ Task Assignment No. EV08-0135). The project was funded by a Brownfields State Response Grant through the federal government. The scope of work included preparation of a Work Plan, Sample and Analysis Plan (SAP), field investigation, and preparation of a final ESA report. Results of the investigation indicated that levels of contaminants present on the site were below applicable non-residential soil remediation levels. The SAP and report findings were reviewed and approved by ADEQ and the U.S. Environmental Protection Agency (EPA). Project status: Completed June 2009 within budget and on schedule.
Client: Greeley and Hansen, LLC
Dates: Aug. 2010 – Mar. 2011
Tasks: Investigation of Alert Level (AL) Exceedance for Nitrate
Project Description: SGC was retained by Greeley and Hansen to conduct a hydrogeologic investigation in an attempt to determine the cause of AL exceedances for nitrate in groundwater samples at the 91st Avenue Wastewater Treatment Plant (WWTP). SGC reviewed all available data and background information concerning operation of the WWTP and groundwater monitoring. Because historical data for plant effluent discharges show Nitrate-N concentration values below 10 mg/L, it was concluded that there is no connection between plant effluent discharges and the high nitrate levels detected in the groundwater monitoring wells.
Following extensive review of groundwater elevation data from 2003 to the present, it became apparent that the periods of high nitrate concentrations in groundwater samples appeared to coincide with periods of recharge related to flows in the Salt River channel. It is SGC’s opinion that these periodic flooding events, which ultimately lead to higher groundwater elevations, are mobilizing nitrate in the vadose zone resulting in the high nitrate levels.
SGC prepared a hypothetical groundwater flow model for the area using local monitor well and dewatering well data. Results of the model indicate that on-site dewatering activities do not appear to be changing the groundwater gradient to the point of causing nitrate contaminated groundwater to migrate onto the site.
SGC and Greeley and Hansen presented the results to the City of Phoenix for their review and approval.
Client: Foxworth-Galbraith Lumber Company
Dates: Oct. 2004 – Present
Tasks: Installation of monitor wells, compliance monitoring (on-going)
Project Description: SGC installed monitor wells and performed groundwater monitoring to characterize the vertical and lateral extent of contamination emanating from a former Leaking Underground Storage Tank (LUST). SGC negotiated clean-up requirements with the Arizona Department of Environmental Quality in order to implement the most efficient and cost effective remedial strategy for the site. Periodic monitoring and reporting are on-going components of this project.
Client: City of Prescott
Dates: Feb. – Nov. 2009
Tasks: Expert witness testimony, technical support
Project Description: SGC was contracted by the City of Prescott (the City) to provide expert witness testimony and technical support at an 8-day administrative hearing in the State of Arizona Office of Administrative Hearings on behalf of the City in the Matter of the Decision of the Director to Grant the City of Prescott’s Application for Modification of its Assured Water Supply Designation No. 86-401501.0001 (Docket No. 08A-AWS001-DWR).
Client: Smurfit-Stone Container Corporation
Dates: May 1994 – March 2004
Tasks: Complete site characterization, treatment, and closure on Tribal Lands
Project Description: Extensive soil and groundwater contamination were characterized at a wood treatment facility. Under direct EPA and Yavapai-Prescott Tribe oversight, SGC personnel conducted the Phase I and Phase II site characterizations, treatability studies, pilot treatment, source remediation and closure of the site.
The groundwater component of the site closure required extensive well installation and monitoring of the well field. This work was also conducted under direct EPA and Yavapai-Prescott Tribe oversight. Split samples were provided to the agency. Field practices, laboratory QA/QC and reporting was consistent with EPA’s Quality Program.
The monitoring program extended over a period of ten years. The well field included twelve wells or well points. A total of 16,826 analyses were completed, evaluated, reported and approved.
SGC conducted a detailed risk analyses to determine the toxicity of site contaminants and negotiate final cleanup levels. Approximately 100,000 tons of soil was remediated. Groundwater monitoring confirmed that the soil treatment was effective in reducing levels of the contaminants of concern to non-detect levels.
SGC received a closure letters from the EPA and the Yavapai-Prescott Tribe. The USGS and U.S. Fish and Wildlife confirmed the SGC findings. No further action is necessary at the site. The landowner has placed the property on the market for office/retail development.
From the Yavapai-Prescott Indian Tribe…
October 10, 2003 – At this time, the Yavapai-Prescott Indian Tribe (Tribe) is pleased with the work that Southwest Ground-water Consultants, Inc. performed at the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) site on the Yavapai-Prescott Indian Reservation. When the land is returned to the Tribe, we look forward to benefitting from its economic capability. Although it has been a long process, the return of our land allows the Tribe to continue to grow towards self sufficiency and prosperity for its members.
The Tribe appreciates the diligent work of Southwest Ground-water Consultants, Inc. and its employees at the CERCLA site. The Tribe also sincerely appreciates the EPA’s assistance with this project… (read full text here)
Ernest Jones, Sr.
President/Tribal Board of Directors
Client: Southwest Value Partners
Dates: March 2010 – May 2014
Tasks: Technical review, groundwater flow modeling, expert witness testimony
Project Description: SGC was contracted by Southwest Value Partners (SWVP) to provide an in-depth technical review of Aquifer Protection Permit (APP) and Underground Injection Control (UIC) permit applications for the proposed Florence Copper Project. The Florence Copper Project proposes to inject a dilute sulfuric acid solution (lixiviant) into the oxide bedrock beneath the facility for the purpose of dissolving copper from the fractured rock and recover that solution for above ground processing. SGC also provided technical support reviewing and testing the groundwater flow and fate and transport modeling presented in APP and UIC applications presented by Florence Copper, Inc. (FCI). SGC modelers ran several test scenarios including particle track analysis and transport modeling.
In the course of this project, SGC provided expert witness testimony and technical support during administrative hearings in the Office of Administrative Hearings on behalf of multiple appellants regarding ADEQ’s issuance of a Temporary Individual APP for a Production Test Facility (“PTF”) at Florence, Arizona to develop data for an APP application for a full-scale in-situ leach (“ISL”) copper/in-situ copper recovery (“ISCR”) commercial mine (Case No. 12-005-WQAB).
Client: Graif Barrett & Matura, P.C.
Dates: Oct. 2011 – Jan. 2014
Tasks: Expert witness testimony, technical support
Project Description: SGC was contracted by Graif Barrett & Matura, P.C., counsel for the Town of Colorado City, to provide expert witness testimony and technical support for legal proceedings on behalf of defendants in the case of Cooke VS Colorado City held in United States District Court, District of Arizona.