Attachment_D-_Well_Sampling_SOP_Sept_2025.pdf

PDF 889 KB Posted

Attached to
Monitoring Well Sampling Services
Solicitation number
RFP-SM-0113
Issued by
Los Angeles County, California

About this file

This document is a Standard Operating Procedure (SOP) for Monitoring Well Sampling Services issued by the West Basin Municipal Water District (WBWMD), involving multiple agencies including the Los Angeles County Department of Public Works (LACDPW), Los Angeles Regional Water Quality Control Board (LARWQCB), and Water Replenishment District of Southern California. The SOP covers groundwater sampling procedures for 11 monitoring wells associated with the West Coast Basin Barrier Project under Order R4-2006-0069. The sampling is conducted quarterly for most wells, with well WB-1 potentially requiring monthly sampling, and involves collecting water samples for compliance reporting, water quality testing, and preventing seawater intrusion in the groundwater basin.

The sampling services contract requires comprehensive field sampling protocols, including well purging, water level measurement, sample collection, and water hauling. Specific requirements include using dedicated equipment, following strict contamination prevention measures, and adhering to precise sampling techniques for different types of analyses. Water from certain wells (9B, 14B, 735A, and WB-1) must be hauled to the Edward C. Little Water Recycling Facility's equalization basin, with truck specifications limiting vehicles to 2-axle and 3000-gallon capacity. The contractor must provide all necessary equipment, including submersible pumps, generators, safety gear, and follow detailed procedures for sample collection, with particular attention to volatile organic compound (VOC) and total organic carbon (TOC) sample handling.

View the file

Other files

File Type Posted
Monitoring_Well_Sampling_Services_(Addendum_#1_Revision).pdf PDF
Monitoring_Well_Sampling_Services_(Addendum_#1_Revision).pdf PDF
Vendor-Information-Request-Form-fillable.pdf PDF
Vendor-Information-Request-Form-fillable.pdf PDF
Attachment_A-_Well_Sampling_Scope.pdf PDF
Attachment_C-_Cost_Breakdown.xlsx XLSX spreadsheet
Attachment_B-_Well_Information.pdf PDF
Attachment_D-_Well_Sampling_SOP_Sept_2025.pdf PDF
Attachment_A-_Well_Sampling_Scope.pdf PDF
Attachment_C-_Cost_Breakdown.xlsx XLSX spreadsheet
Attachment_B-_Well_Information.pdf PDF
Form_1_-_Engineering_Service_-_102618.docx DOCX document
Sample_Agreement_-_Form_4_-_Non-Pro_Consultant.docx DOCX document
Sample_Agreement_-_Form_7_-_General_Services.docx DOCX document
Sample_Agreement_-_Form_8_-_Transportation_Services.docx DOCX document
Form_1_-_Engineering_Service_-_102618.docx DOCX document
Sample_Agreement_-_Form_5_-_On-Call_Engineering_Service.docx DOCX document
Sample_Agreement_-_Form_5_-_On-Call_Engineering_Service.docx DOCX document
Sample_Agreement_-_Form_7_-_General_Services.docx DOCX document
Form_3_-_Pro-Svc_Non-Tech_-_102618.docx DOCX document
Sample_Agreement_-_Form_9_-_Supply.docx DOCX document
Form_3_-_Pro-Svc_Non-Tech_-_102618.docx DOCX document
Sample_Agreement_-_Form_4_-_Non-Pro_Consultant.docx DOCX document
Sample_Agreement_-_Form_8_-_Transportation_Services.docx DOCX document
Sample_Agreement_-_Form_9_-_Supply.docx DOCX document
Show all 25

On GovTribe

Work with this file

  • Download the original file
  • Contacts named in this file
  • Similar government files
  • Ask GovTribe AI about this file

Text version

Attachment D - Well Sampling SOP

West Basin Municipal Water District

Monitoring Well Sampling Services RFP

Monitoring Well SOP September 2025

WEST BASIN MUNICIPAL WATER DISTRICT

STANDARD OPERATING PROCEDURE

WEST COAST BASIN BARRIER PROJECT

MONITORING WELLS

FIELD COMPLIANCE SAMPLING

WEST BASIN MUNICIPAL WATER DISTRICT

STANDARD OPERATING PROCEDURE

WEST COAST BASIN BARRIER PROJECT MONITORING WELLS

FIELD COMPLIANCE SAMPLING

TABLE OF CONTENTS

1. DEFINITIONS

2. SCOPE AND APPLICATION

3. WELL IDENTIFICATIONS

4. SITE ACCESSIBILITY

5. WELL SAMPLING SERVICES CONTRACT

6. SUMMARY OF METHOD

7. HEALTH & SAFETY WARNINGS

8. INTERFERENCES

9. PERSONNEL QUALIFICATIONS

10. EQUIPMENT AND SUPPLIES

11. SCHEDULING AND NOTIFICATIONS

12. PERMITS

13. TRAFFIC CONTROL AND MUNICIPAL PUBLIC WORKS NOTIFICATION

14. WATER HAULING

15. ON-SITE WELL SAMPLING PROCEDURE

16. BIBLIOGRAPHY

17. FIELD LOG DATA SHEET (Sample)

1. DEFINITIONS

Chain of Custody – Paper trail documenting control and transfer of water quality samples from sampler to analytical labs

ECLWRF – Edward C. Little Water Recycling Facility

LACDPW – Los Angeles County Department of Public Works

LACFCD - Los Angeles County Flood Control District (a branch of LACDPW)

LARWQCB – Los Angeles Regional Water Quality Board

NPDES – National Pollution Discharge Elimination System

WBWMD – West Basin Municipal Water District

WBWQL - West Basin Water Quality Lab

WCBBP – West Coast Basin Barrier Project

WRD – Water Replenishment District of Southern California

2. SCOPE AND APPLICATION

This Standard Operating Procedure (SOP) is applicable to the collection of groundwater samples from West Coast Basin Barrier Project (WCBBP) monitoring wells, for water quality compliance reporting under Order R4-2006-0069 (West Coast Basin Barrier Project), issued to the West Basin Municipal Water District (WBMWD) by the Los Angeles Regional Water Quality Control Board (LARWQCB).

WBMWD owns the Edward C. Little Water Recycling Facility (ECLWRF), located in El Segundo. The ECLWRF provides additional treatment processes to secondary-treated wastewater from the City of Los Angeles Hyperion Water Reclamation Plant (HWRP): 1) The “Title 22” (tertiary-treated) process;

2) micro-filtration/reverse osmosis (MF/RO) product water for use in boilers at the Chevron Refinery in El Segundo; and 3) “Barrier” (advanced-treated) process. An onsite lab (West Basin Water Quality Laboratory, or WBWQL) performs process control and some compliance water quality testing. The ECLWRF and WBWQL are currently operated under contract by Jacobs.

Barrier product water produced at ECLWRF is blended with imported disinfected surface water from Metropolitan Water District of Southern California (MWD) and injected into the West Coast Basin Barrier Project (WCBBP), a subsurface hydraulic barrier system of roughly 157 injection wells from El Segundo to Palos Verdes, owned and operated by the Los Angeles County Department of Public Works (LACDPW). The WCBBP prevents seawater intrusion and recharges the groundwater basin.

Order R4-2006-0069 requires testing of 11 groundwater observation wells (monitoring wells) on a regular basis. Constituents are required at specific frequencies. The WBMWD Compliance Department and West Basin Water Quality Lab staff manage the monitoring well sampling schedules and provide sample containers and coolers. The sampling contractor supplies sampling expertise, labor, and equipment to measure the required water quality parameters. The map below as well as those in Attachment 2 of the RFP show the location of the monitoring wells under Order R4-2006-0069. One of the wells (WB-1) is a nested well of 3 depths.

The scope of this SOP is limited to the field practices and protocols for monitoring well sampling. This scope does not apply to sampling of WCBBP injection wells or domestic supply wells.

3. WELL IDENTIFICATIONS

The wells under this SOP are in the table below. Identifications are cross-referenced with WBMWD, LACDPW, and Los Angeles County Flood Control District (LACFCD) numbers. Detailed maps of well locations are in RFP Attachment 2. Wells are owned by LACDPW or West Basin.

West Basin Well ID

Flood Control District ID

LACDPW

Project Number

Wellhead Cap Color (if nested) City

Well 1318N 1318N 4Z26 White El Segundo Well 14B 712K 7H27 Red Redondo Beach Well 17B 725BP 8T10 Red Torrance Well 17C 725BQ 8T10 White Torrance Well 690A 690A 5YA None Manhattan Beach Well 703G 703G 7LN None Hermosa Beach Well 735A Well 735A 9A31 White Torrance

Well 9B 700H 6B36 White Manhattan Beach

Well WB1 380' None: Owned by WBMWD

None: Owned by

WBMWD

None: tallest casing in vault

Redondo Beach/ Torrance

Well WB1 490' None: Owned by WBMWD

None: Owned by

WBMWD

None: mid-length casing in vault

Redondo Beach/ Torrance

Well WB1 640' None: Owned by WBMWD

None: Owned by

WBMWD

None: shortest casing in vault

Redondo Beach/ Torrance

Well Ownership

Monitoring wells are owned by either LACDPW or West Basin. WBMWD owns well WB-1 (a nested well of 3 depths – 380 ft., 490 ft., and 640 ft.). The remaining wells are owned by LACDPW.

4. SITE ACCESSIBILITY

All monitoring wells except one (1318N) are located in publicly accessible areas. Well 1318N is located on the property of the LACFCD El Segundo Field Yard, located at 100 Nash St. in El Segundo (just north of El Segundo Blvd), behind a code-accessed gate. The current code as of September 2025 is:

West Basin staff will notify well sampling crews when the gate code changes.

Well WB-1 requires a well vault key to open. WBMWD will provide this key upon contract award.

5. WELL SAMPLING SERVICES CONTRACT

WBMWD contracts for all monitoring well sampling tasks. The contract scope covers sampling services for the following wells:

• Quarterly sampling: Wells 9B, 14B, 17B, 17C, 690A, 703G, 735A, 1318N. West Basin staff will be responsible for temporary no parking signage required for 9B, 14B, and 735A.

• Currently quarterly (may be adjusted to monthly if required): WB-1 380 ft., WB-1 490 ft., and WB-1 640 ft. Contractor is responsible for lane closure implementation with proper equipment and signage, further discussed in Sec. 13.

• Contractor may also be requested to sample wells on a more frequent basis due to water quality issues, or for special studies.

6. SUMMARY OF METHOD

Monitoring well sampling consists of two main activities: Well purging and collection of the purged samples for field or lab analysis. Purging (pumping out) stagnant water from the well casing assures that collected samples will represent uniform subsurface water quality from the screened interval. Two casings should be used as the minimum purged volume needed to ensure a representative sample.

Sample analyses characterize the water quality representative of the aquifer.

7. HEALTH & SAFETY WARNINGS

When working with potentially hazardous materials or situations, follow all applicable health or safety procedures and precautions, including but not limited to:

• Appropriate lane closure setup when monitoring well is located on a public street or right-of-way.

• Use of Personal Protective Equipment (PPE - gloves, etc.) to avoid contact or exposure to preservatives, acids, and bases in sampling containers; and to prevent cross- contamination of analytes of interest.

• Lifting injuries, heat and cold stress, slip, trip, and fall conditions

• Electrical shock associated with using submersible pumps

8. INTERFERENCES

Interference from field measurements or laboratory analyses may result from using contaminated sampling equipment or sample containers, solvents or reagents, or sampling under conditions that may compromise analytical data (such as collecting samples near vehicle exhaust, soiled gloves, or phthalate-containing plastics). Cross-contamination can be minimized or eliminated by using dedicated sampling equipment and PPE. Decontamination is required between sampling sites in order to minimize this contamination. For analytes such as PFAS where cross-contamination is very common, additional field and/or equipment blanks should be used. Follow current sampling guidelines for these compounds.

9. PERSONNEL QUALIFICATIONS

All field samplers should be trained by an experienced sampler before initiating any field sampling activities. Field sampling personnel are responsible for complying with all necessary quality assurance/quality control requirements that pertain to this SOP.

10. EQUIPMENT AND SUPPLIES

The items below are the equipment and supplies suggested for sampling. This list is not exhaustive, and it is subject to change based on new sampling requirements.

Equipment & tools:

• Pump controller box programmed for 2” or 3” submersible pump

• 3600-watt generator with 120/220 V power source

• Spare gas in 5-gal can

• 2” or 3” submersible pump with 200 ft. of attached hose on reel

• 50-ft. hose for discharge from hose reel setup

• Sounder (water depth measuring device)

• Sample containers in coolers with pre-frozen blue ice (or wet ice in accordance with specific sampling guidelines for some analytes)

• Screwdriver kit (precision and regular)

• Pop-up canopy for rainy/hot weather (optional)

Tools, safety:

• Manhole cover opener tools (large & small)

• WD-40 (for rusty manhole covers)

• Lane closure supplies (cones, signage, arrow board), disposable nitrile gloves

• Disposable 0.45 micron filter with short plastic hose (for filtering trace metals samples)

• Extra submersible pump parts (seals, impellors)

Field parameter equipment/misc. equipment:

• Portable meters for measuring turbidity, total & free residual chlorine, dissolved oxygen, conductivity, pH, temperature

• Deionized water in squeeze bottle

• Folding table/chairs (optional), paper towels, handi-wipes, clean rags

• 3-ring binder with copies of: 1) this SOP, 2) blank field log sheets, 3) well location maps, 4) submersible pump operation/maintenance information, 5) current permits (LACDPW well access permit, municipal encroachment/traffic control permits; and 6) public outreach materials on WBMWD and water recycling

11. SCHEDULING AND NOTIFICATIONS

WBMWD staff will reach out to the sampling contractor via email near the middle of each quarter to set a sampling schedule for the following quarter, subject to confirmation by the WBWQL.

Sampling days are limited to Monday through Thursday. Fridays, weekends, and holidays cannot be scheduled due to short analytical holding times.

Once the sampling schedule is finalized, LACDPW must be advised of the schedule pursuant to the well access permit described earlier in Sec. 2 (Scope and Application) to mitigate any conflicts with well maintenance by LACDPW field crews. This communication applies only to LACDPW-owned wells 9B, 14B, 17B, 17C, 690A, 703G, 735A, and 1318N.

LACDPW contacts as of this SOP version are:

• Adam Lee, PE, Assoc. Civil Engineer awlee@dpw.lacounty.org 626-458-6185

• Orbel Jaramillo (Field crew supervisor) ojaramillo@dpw.lacounty.gov 562-480-7187

Any scheduling changes, or additional dates scheduled outside the quarterly sampling schedule must be communicated to LACDPW.

12. PERMITS

Traffic control (encroachment or right-of-way) permits are required for Wells 9B, 14B, 735A, and WB-1 at all three depths due to temporary partial obstruction of traffic or street parking. WBMWD is responsible for procuring the required permits and distributing them to the sampling contractor. It should be noted that the contractor is responsible for following the specifications within the permits.

Access permits are also required by LACFCD to work in the right-of-way for the LACDPW-owned wells.

WBMWD applies for these permits annually, and a copy will be provided to the contractor upon award.

13. TRAFFIC CONTROL AND MUNICIPAL PUBLIC WORKS NOTIFICATION

Current and valid encroachment permits are required for the following monitoring wells due to their location: DISTRICT's laboratory will provide the preservatives and instruction in field preservation.

A. LACDPW well 9B, located in Manhattan Beach on residential street w/ minor traffic. West Basin applies for right-of-way permit quarterly with every sampling schedule; permit retained on file w/ city. West Basin is responsible for any notification to the city, and mobilization/demobilization of any traffic control devices. Contractor may be asked to assist with demobilization (returning cones to ECLWRF along with samples).

B. LACDPW well 14B, located in Redondo Beach on residential street w/ minor traffic. West Basin applies for parking restriction permit every 6 months; permit and traffic plan on file w/ city; re-apply/re-new every 6 months. West Basin is responsible for any notification to the city, and mobilization/demobilization of any traffic control devices. Contractor may be asked to assist with demobilization (returning cones to ECLWRF along with samples).

WBMWD also takes daily, time-stamped photos 72 hr prior to, and the day of sampling and submits them with a parking form to the city in order to enforce the parking restrictions at the well site.

C. LACDPW well 735A, located in Torrance on residential street w/ minor traffic. West Basin is responsible for any notification to the city, and mobilization/demobilization of any traffic control devices. Contractor may be asked to assist with demobilization (returning cones to ECLWRF along with samples).

D. West Basin-owned triple-nested well WB-1, located at a signaled traffic intersection overlapping two municipal jurisdictions (Torrance and Redondo Beach). Full lane closure (with arrow board) is mailto:awlee@dpw.lacounty.org mailto:ojaramillo@dpw.lacounty.gov required due to well location. Traffic control at this location must be provided by the contractor. The Contractor will mobilize and de-mobilize all necessary cones, flags, and arrow boards to comply with City of Torrance traffic control requirements (also compliant with the Manual for Uniform Traffic Control Devices, or MUTCD).

• Torrance permit and traffic plan on file w/ city; renewed annually. Lane closure permitted M-F

8:30 am-3:30 pm. West Basin staff will contact Torrance at least two working days prior to the date of sampling for any field inspections. The contact for this notification is:

Torrance Community Development Dept. (Voice mail messages are accepted)

310-618-5898

• Redondo Beach permit and traffic plan on file w/ city; renewed every six months. Lane closure permitted M-F 9:00 am-3:00 pm. West Basin staff will contact Redondo Beach two working days prior to the date of sampling for any field inspections. The contact for this notification is:

Redondo Beach Public Works Dept, Engineering Services

310-318-0661

14. WATER HAULING

As of January 2019, water from the following wells must be hauled away by truck: 9B, 14B, 735A, and WB-1 at all three depths. Prior to 2019, the lack of nearby vegetation at these well locations required discharge to storm drain under a NPDES permit that expired in December 2018. Water quality at these wells did not comply under the replacement permit’s limits; hence the need to cease discharge to the storm drain. In lieu of on-site treatment, the water is hauled to the equalization basin at ECLWRF.

Well water hauling is a component of the contracted sampling services and must be provided by the Contractor.

Jacobs staff at ECLWRF are notified prior to a water load arriving at ECLWRF for disposal. Contractor will notify and coordinate with Jacobs for disposal. If required by Jacobs, Contractor will take a pH and conductivity reading of the water to provide before disposal. The current Jacobs contacts are Steve Sato (213-414-2127) or Sokna Sim (213-414-3714).

Trucks must be limited to 2-axle and of no larger than 3000-gal capacity due to well locations in residential areas.

15. ON-SITE WELL SAMPLING PROCEDURE

A. Well Sounding

Prior to opening caps on any well with telemetry equipment and cabling, contact LACDPW (Jason St. Pierre 626-458-6189; or Adam Lee 626-458-6185. As of 2025, wells with such equipment are 690A (LACDPW ID 5YA) and 703G (LACDPW ID 7LN). After the purging is completed, contact LACDPW again to confirm the telemetry is working.

Take notes on all aspects of field sampling activities: Sampler names, pertinent observations, any noticeable anomalies of the well or purged water, equipment difficulties, weather, etc. Fill out field logs completely and legibly and keep them dry. An example of the field log sheet is in Section 17.

Set up and maintain a safe and efficient work area. Place equipment and sample container coolers out of the sun if at all possible.

Remove the manhole cover and well cap.

Check the water level of the well with the sounder. The sounder consists of a calibrated tape measure wound on a spool with a probe at the end of the tape. Check the sounder’s audible signal prior to lowering the sounder into the well casing. The sounder’s on/off/volume control is located on the side of the spool, next to the test button.

Release the brake on the spool and lower the sounder probe into the well. An audible signal will be heard when the probe reaches the water level. Slowly retract the probe until the signal stops. Read the depth on the calibrated tape at the top of the well casing (not the top of the manhole).

Measurements are in 10-ft. increments, beginning at 50 ft. of depth. Record the depth to the nearest 0.1 ft. on the field log sheet. Be sure to turn off the sounder.

B. Standard Purging

NOTE: Dedicated 2” Grundfos pumps with electrical leads for the controller box, generator and hose lead are installed on all 3 depths on Well WB-1. When purging well WB-1 with a portable submersible pump or bladder pump, omit step B and go directly to step C

Top off the submersible pump coolant reservoir with de-ionized water. The coolant reservoir is accessed on the bottom of the pump with a countersunk fitting fit with an o-ring. Fill the reservoir, screw the fitting back on, and gently invert the pump several times to distribute the de-ionized water. Repeat the procedure several times to completely fill the reservoir.

Check the generator for gas & oil, top off in necessary, and set the generator for 220 volts. Start the generator and let it warm up for a few minutes. Make the appropriate electrical connections to the control box, generator, and hose lead.

For purging using standard 2- or 3-volume method, position the pump in the well casing approximately 10-15 ft. below the measured static water line to minimize head when purging, and to reduce sediment contamination during sampling. Position the discharge hose according to site-specific needs. Descriptions of site-specific discharge are on the well location maps in Appendix A.

• Discharge to nearby vegetation, if field conditions permit (limited to wells 17B, 17C, 703G, and 690A at this time)

• Discharge to the LACDPW field yard cleanout (for well 1318N)

• Divert discharge water to a truck/trailer for disposal at ECLWRF (14B, 735A, 9B, and WB-

1 at all three depths).

Program the controller box to pump at a moderate frequency (about 350 hz) for about 10 minutes, And then ramp up the frequency to 380 hz. If pump shuts off repeatedly (indicated by an audible power surge from the generator), then the pump may need field maintenance or servicing.

When operating frequency is maintained and pumping is stabilized (usually a few minutes), measure the flow rate using a stopwatch and a 1-liter container. Take the average of 3 readings in order to calculate flow rate using the following formula:

Flow rate (gpm) = (1liter/average time in sec.) x (60 sec/1 min) x (1 gal/3.785 liters)

A sample calculation is given below using an average of 4.2 sec:

Flow rate (gpm) = (1liter/4.2 sec.) x (60 sec/1 min) x (1 gal/3.785 liters) = 3.8 gpm

Using the flow rate and the calculation below, calculate the purge time for 3 well volumes:

Volume (gal) = πr2 x (h2-h1) x 7.4805

Where:

π = pi (3.14) r = well radius in feet (most well casings are 4” diameters. This translates to 0.166 ft) h1 =total well depth in ft. (from well completion report) h2 =depth to water surface in ft.

7.4805 = converts ft3 to gal.

A sample calculation is given below for a well with a 4” diameter casing, 300’ total depth, and measured water level of 100’:

Volume (gal) = π (0.166)2 x (300-100) x 7.4805 = 129.5 gal

2 well casings is 2 x 129.5 gal = 259 gal 3 well casings is 3 x 129.5 gal = 389 gal

Under most situations, monitoring wells are purged the equivalent of 2-3 times the well volume of water. Well purging may be shortened if impending rainy weather, significantly reduced pump output, or safety is a concern; or if purging with a low-flow bladder pump. Note any shortened purge times on the field log sheet.

Measure and record the following parameters on the discharge water at approximately 1-hour intervals using the field equipment: Dissolved oxygen (DO, in mg/L), pH, Conductivity (in µmhos/cm), temperature (in degrees C) and chlorine residual (free and total). Measure and record a final set of measurements immediately before collecting samples.

Reconnect any telemetry equipment (Wells 690A and 703G). Contact LACDPW with water elevation data (Jason St. Pierre 626-458-6189; or Adam Lee 626-458-6185) in order to ensure the signal is still being received.

C. Low Flow Purging, Well WB-1 380 ft. only (USEPA procedure)

Initial Water Level Measure the water level in the well before installing the pump if a non-dedicated pump is being used. The initial water level is recorded on the purge form or in the field logbook.

Install Pump Lower pump, safety cable, tubing and electrical lines slowly (to minimize disturbance) into the well to the appropriate depth (must be within the screen interval of the well). Pump tubing lengths, above the top of well casing should be kept as short as possible to minimize heating the groundwater in the tubing by exposure to sunlight and ambient air. Heating can cause the groundwater to degas, which is unacceptable for the collection of samples for VOC and dissolved gases analyses.

Measure Water Level Before starting pump, measure water level. Install recording pressure transducer, if used to track drawdowns, to initialize starting condition.

Purge Well From the time the pump starts purging and until the time the samples are collected, the purged water must be measured to determine the total volume of groundwater purged. Record the information on the purge form or field logbook. Start the pump at low speed and slowly increase the speed until discharge occurs. Check water level. Check equipment for water leaks, and if present, fix or replace the affected equipment. Try to match pumping rate used during previous sampling event(s). Otherwise, adjust pump speed until there is little or no water level drawdown.

If the minimal drawdown achieved exceeds 0.3 feet, but remains stable, continue purging.

Monitor and record the water level and pumping rate every five minutes (or as appropriate) during purging. Record any adjustments (both time and flow rate). Pumping rates should, as needed, be reduced to the minimum capabilities of the pump to ensure stabilization of the water level.

Adjustments are best made in the first fifteen minutes of pumping in order to help minimize purging time. If the initial water level is above the top of the screen, do not allow the water level to fall into the well screen. The final purge volume must be greater than the stabilized drawdown volume plus the pump’s tubing volume. If the drawdown has exceeded 0.3 feet and stabilizes, calculate the volume of water between the initial water level and the stabilized water level. Add the volume of the water which occupies the pump’s tubing to this calculation. This combined volume of water needs to be purged from the well after the water level has stabilized before samples are collected. Avoid the use of constriction devices on the tubing to decrease flow rate because it will cause a pressure difference in the water column. This will cause the groundwater to degas and result in a loss of VOCs and dissolved gasses in the groundwater samples.

Note: the flow rate used to achieve a stable pumping level should remain constant while monitoring the indicator parameters for stabilization and while collecting the samples.

Wells with low recharge rates may require the use of bladder or peristaltic pumps capable of attaining very low pumping rates. A water level measurement needs to be taken and recorded before samples are collected. Note that field conditions and efforts to overcome problematic situations must be recorded in order to support field decisions to deviate from normal procedures.

Monitor Indicator Field Parameters After the water level has stabilized, connect the “T” connector with a valve and the flowthrough-cell to monitor the indicator field parameters. During well purging, monitor indicator field parameters (such as temperature, specific conductance, pH, DO) at a frequency of five-minute intervals or greater. The pump’s flow rate must be able to “turn over” at least one flow-through-cell volume between measurements. If the cell volume cannot be replaced in the five-minute interval, then the time between measurements must be increased accordingly. Purging is considered complete and sampling may begin when all the above indicator field parameters have stabilized. Stabilization is considered to be achieved when three consecutive readings are within the following limits:

• Turbidity (10% for values greater than 5 NTU; if three Turbidity values are less

• than 5 NTU, consider the values as stabilized),

• Dissolved Oxygen (10% for values greater than 0.5 mg/L, if three Dissolved

• Oxygen values are less than 0.5 mg/L, consider the values as

• stabilized),

• Specific Conductance (3%),

• Temperature (3%),

• pH (± 0.1 unit)

The flow-through-cell must be designed in a way that prevents gas bubble entrapment in the cell.

Placing the flow-through-cell at a 45-degree angle with the port facing upward can help remove bubbles from the flow-through-cell. Throughout the measurement process, the flow-through-cell must remain free of any gas bubbles. Otherwise, the monitoring probes may act erratically. When the pump is turned off or cycling on/off (when using a bladder pump), water in the cell must not drain out. Monitoring probes must remain submerged in water at all times.

Collect Water Samples See section below.

Post Sampling Activities

After collection of samples, the pump tubing may be dedicated to the well for re-sampling (by hanging the tubing inside the well), decontaminated, or properly discarded. Before securing the well, measure and record the well depth (to 0.1 ft.). Secure the well. Replace well caps and manhole covers, and clean-up site. Complete the Chain of Custody (COC) including date and time sampled. Deliver samples in coolers to the WBWQL for processing. Don’t forget to sign, date and time on the bottom of the COC when releasing samples to the WBWQL staff.

D. Sample Collection

While the well is being purged, label sample bottles with the well name and “grab” sample type (if sample type is not pre-labeled). Each quarter, a well will be designated by lab staff as the quality control (QC) well. Containers will be provided to collect QC samples on this well.

Set up the discharge hose for ease of sampling. Reduce the flow to minimize splashing and aeration in volatile organics samples.

Fill sample containers with raw water from the discharge hose. Fill in date & time sampled when samples are collected. With the exception of volatiles (VOA) and Total Organic Carson (TOC) analyses, fill all containers to about 90% full (to the shoulder of the sample container).

Reduce the flow to about 1 gpm before filling VOC and TOC containers to leave no headspace or bubbles.

Sample collection protocol for total/fecal coliform samples: With clean gloves or clean un-gloved hands, remove cap from the sample bottle without touching the inside of the cap or bottle, fill the bottle above the 100 mL line, but not completely full, recap tightly.

Many sample containers are pre-preserved with acids or bases or other chemicals; take care not to rinse out preservative or fill any container to overflowing, potentially losing preservative.

Filter all samples for metals analysis (boron, iron, cations, mercury or other metals) with a 0.45-micron disposable filter at the end of the discharge hose before filling sample container.

Chill samples in cooler after collection with blue ice (or wet ice in accordance with analyte-specific sampling protocols) provided with the cooler.

16. DATA MANAGEMENT

Electronic versions (pdfs) of the field logs will be transmitted to WBMWD staff by the well services contractor. West Basin staff will enter the field measurement data in WaterTrax for each quarterly compliance report.

17. CONTACT INFORMATION

Jamie Burkhard, West Basin Municipal Water District 310-660-6227; JamieB@WestBasinCA.gov (scheduling issues, field analytical or sampling issues)

Jon Arakaki, West Basin Municipal Water District 424-531-5578; JonathanA@WestBasinCA.gov (Traffic control and water hauling communications and field support)

Michelle Phewklieng, Lab Director, West Basin Water Quality Lab 213-414-4701; MichelleP@westbasin.org (field analytical or sampling issues) mailto:JamieB@WestBasinCA.gov mailto:JonathanA@WestBasinCA.gov mailto:MichelleP@westbasin.org

City of Manhattan Beach Planning Dept.

310-802-5504 M-Th 7:30 am-5:30 pm; Fri 7:30 am-4:30 pm (Well 9B encroachment permit application; notifications)

City of Manhattan Beach Parking Control 310-802-5160 M-F 7 am-5 pm (well 690A parking issues)

Redondo Beach Public Works Dept, Engineering Services 310-937-6653 (WB-1 traffic control notifications)

Debra Langsdale, City of Redondo Beach Debra.Langsdale@redondo.org and cc MSO@redondo.org (E-mail Well 14B “No parking” signage photos 72 hr prior to & day of sampling)

Adam Lee, Los Angeles Co. Dept. of Public Works, Water Resources Division 626-458-6185; awlee@dpw.lacounty.org M-Th 7 am-5 pm (sampling schedule notification; confirming telemetry signal on wells 690A and 703G)

Orbel Jaramillo (Field crew supervisor) 562-480-7187; ojaramillo@dpw.lacounty.gov (sampling schedule notification)

Jason St. Pierre, Los Angeles Co. Dept. of Public Works, Water Resources Division 626-458-6189; jstpierre@dpw.lacounty.gov M-Th 7 am-5 pm (confirming telemetry signal on wells 690A and 703G)

Torrance Community Development Dept.

310-618-5898 (WB-1 traffic control notifications)

16. BIBLIOGRAPHY

• GeoTech ENV, Inc. Groundwater Sampling Equipment: Grundfos Redi-flow2 Submersible:

geotechenv.com/ground_water_sampling_equipment/grundfos_redi-flo2.pdf

• USEPA Region 6. Standard Operating Procedure for Groundwater Sampling:

https://www.epa.gov/documents/finalgwsamp_sop.pdf

• USEPA: Low Stress (Low Flow) Purging and Sampling Procedure for the Collection of

Groundwater Samples From Monitoring Wells https://www.epa.gov/sites/production/files/2017-10/documents/eqasop-gw4.pdf mailto:Debra.Langsdale@redondo.org mailto:MSO@redondo.org mailto:awlee@dpw.lacounty.org mailto:ojaramillo@dpw.lacounty.gov mailto:jstpierre@dpw.lacounty.gov https://www.geotechenv.com/pdf/ground_water_sampling_equipment/grundfos_redi-flo2.pdf https://www.epa.gov/documents/finalgwsamp_sop.pdf https://www.epa.gov/sites/production/files/2017-10/documents/eqasop-gw4.pdf

17. FIELD LOG DATA SHEET (Sample)

WEST BASIN MUNICIPAL WATER DISTRICT BARRIER MONITORING WELL FIELD MEASUREMENTS

Flow rate (gpm) = (1 liter / averaged time in sec.) x (60 sec. / 1 min.) x 1 gal. / 3.785 liters) Date: ______________________________________

Purge volume (gal.) = 3.14 x r2 x (ft. of water) x 3 x 7.4805 Well I.D.: __________________________________

Purge time = Purge volume/ Flow rate Pump controller (Hz) _________________________

Time purging started _______________ Time purging stopped _______________ Total purge time _______________ Purge volume _______________

Sampler(s) Water level (in. ft.) to the nearest 0.1 ft. (h1)

Well depth

in. ft. (h2)

Ft. of water (h2-h1) Purge vol. (gal.) Purge time (min.)

Time samples collected

Time Temp (deg. C) pH

(PERMIT

LIMIT

RANGE

6.5-8.5 *) pH

(PERMIT

LIMIT

RANGE 6.5-

8.5) (after adjustment)*

Conductivity (µmhos / cm)

Dissolved oxygen (mg / L)

Pre-dechlorination Total chlorine

(mg / L)

Pre-dechlorination Free chlorine

(mg / L) –

Post-dechlorination Total chlorine

(mg / L) –

PERMIT LIMIT

0.1 mg/L**

Post-dechlorination Free chlorine

(mg / L) –

PERMIT

LIMIT 0.1

mg/L**

* WATER DISCHARGED TO EQ BASIN AT ECLWRF MUST BE IN 6.5-8.5 PH RANGE. ADJUST IF NECESSARY.

PLEASE RECORD PH BEFORE AND AFTER ADJUSTMENT.

** WATER DISCHARGED TO STORM DRAIN MUST BE DECHLORINATED TO LESS THAN 0.1 mg/L

PLEASE RECORD TOTAL AND FREE RESIDUAL CHLORINE BEFORE AND AFTER DECHLORINATING

Note (Dup/MS/MSD collected, de-chlorination or pH adjustments, discharge to vegetation, field conditions, equipment problems, etc.)

1. DEFINITIONS
2. SCOPE AND APPLICATION
3. WELL IDENTIFICATIONS
4. SITE ACCESSIBILITY
5. WELL SAMPLING SERVICES CONTRACT
6. SUMMARY OF METHOD
7. HEALTH & SAFETY WARNINGS
8. INTERFERENCES
9. PERSONNEL QUALIFICATIONS
10. EQUIPMENT AND SUPPLIES
11. SCHEDULING AND NOTIFICATIONS
12. PERMITS
13. TRAFFIC CONTROL AND MUNICIPAL PUBLIC WORKS NOTIFICATION
14. WATER HAULING
15. ON-SITE WELL SAMPLING PROCEDURE
16. BIBLIOGRAPHY
17. FIELD LOG DATA SHEET (Sample)

File details come from the government source that posted it. Updated .