Introduction to Construction General Permit InspectionsField Monitoring at Construction Sites

Outline of the Module

• Background and summary of requirements• Visual Monitoring • Water Quality Monitoring

– Water Quality Sampling Requirements for Risk Levels 2 and 3– Field Equipment– Calibration and Use of Sampling Equipment

• Calibration and Use of pH Meter• Calibration and Use of Turbidity Meters

• Selection and Location of Effluent Sampling Locations • Compliance Sampling Data Management

– Sampling Results– Sample Naming Convention

• Receiving Water Monitoring• Bioassessments

Summary of Monitoring Requirements

Summary of Monitoring Requirements

Risk Level   

Visual Inspections Sample Collection

Quarterly Non-Storm

Water Discharge

Pre-Storm Event Daily

Storm BMP Post Storm

Storm Water

Discharge

Receiving Water

Baseline REAP

1 X X   X X    

2 X X X X X X  

3 X X X X X X X

Summary of LUP Monitoring Requirements

Summary of LUP Monitoring Requirements

LUP Type

Visual Inspections Sample Collection

Daily Site BMP

Pre-Storm Event Daily Storm

BMPPost Storm

Storm Water

Discharge

Receiving Water

Non-Visible (when

applicable)Baseline

1 X           X

2 X X X X X   X

3 X X X X X X X

Reasons for Inspectors to Conduct Field Monitoring or Sampling

• Identify problems with BMP performance or poor coverage of BMPs

• Confirm contractor compliance; or • Gather evidence of a NAL exceedance or a NEL violation

Storm Water Sampling References

• Caltrans Stormwater Monitoring Protocols (Caltrans, July 2003) http://www.dot.ca.gov/hq/env/stormwater/pdf/CTSW-RT-03-105.pdf or,

• EPA NPDES Storm Water Sampling Guidance Document (EPA 833-B-92-001, 1992) http://www.epa.gov/npdes/pubs/owm0093.pdf

• Surface Water Ambient Monitoring Program (SWAMP) 2008 Quality Assurance Program Plan (QAPrP) http://www.swrcb.ca.gov/water_issues/programs/swamp/tools.shtml#qa

Health and Safety

• The inspector must:– Understand and follow safety precautions,– Use proper safety equipment, and – Exercise good judgment when conducting field monitoring

activities. • Preparation of Health and Safety Plans is not covered in this

training • The inspector should refer to their office’s health and safety

program policies and procedures.

Visual Monitoring • Visual monitoring is required of all projects. • Inspectors should be familiar with the CGP requirements for

visual monitoring of construction sites:– Pre-Rain Event; within 48 hours in advance of predicted

qualifying rain event (e.g., when NOAA predicts a probability of precipitation of 50% or more in the project area)

– Daily-Rain Event; during every extended rain event – Post-Rain Event; within 48 hours following an actual qualifying

rain event• Non-Storm Water Inspections; Routine quarterly non-storm

water inspections of all project drainage areas• Weekly Visual; year round

Risk Level 2 Monitoring Requirements

Risk Level 2 Test Methods, Detection Limits, Reporting Units and Applicable NALs

ParameterTest

Method/Protocol

Discharge Type

Min. Detection Limit

Reporting Units

Numeric Action Level

pH

Field test with calibrated portable

instrument

Risk Level 2 Discharges

0.2 pH Units

Lower NAL = 6.5

Upper NAL = 8.5

Turbidity EPA

0180.1 and/or field test with

calibrated portable

instrument

Risk Level 2 Discharges

other than ATS1 NTU   250 NTU

For ATS Discharges

1 NTU   N/A

Risk Level 3 Monitoring Requirements

Risk Level 3 Test Methods, Detection Limits, Reporting Units and Applicable NALs/NELs

ParameterTest

Method/Protocol

Discharge Type

Min. Detection

Limit

Reporting Units

Numeric Action Level

Numeric Effluent

Limitation

pH

Field test with calibrated portable

instrument

Risk Level 2 Discharges

0.2 pH units

Lower NAL = 6.5 Lower NEL =

6.0Upper NAL = 8.5

Turbidity EPA

0180.1 and/or field test with

calibrated portable

instrument

Risk Level 2 Discharges other than

ATS

1 NTU   250 NTU500 NTU

For ATS Discharges

1 NTU   N/A

SSC ASTMMethod D 3977.97

Risk Level 3 (if NEL

exceeded)5 mg/L   N/A N/A

Bioassessment

(STE) Level 1 of (SAFIT),

fixed count of 600

org/sample

Risk Level 3 projects > 30

acresN/A   N/A N/A

LUP Monitoring Requirements

LUP Type 2 & 3 Effluent Monitoring Requirements

LUP Type Frequency Effluent Monitoring

2

Minimum of 3 samples per day characterizing discharges

associated with construction activity from the project active

areas of construction.

Turbidity, pH, and non-visible pollutant parameters (if

applicable)

3

Minimum of 3 samples per day characterizing discharges

associated with construction activity from the project active

areas of construction.

turbidity, pH, suspended sediment concentrations

(SSC)13 (only if turbidity NEL exceeded), plus non-visible

pollutant parameters (if applicable)

LUP Monitoring Requirements

Test Methods, Detection Limits, Reporting Units and Applicable NALs/NELs

Parameter Test MethodDischarge

Type

Min Detection

Limit

Reporting Units

Numeric Action Levels

Numeric Effluent

Limitation (LUP Type 3)

pHField test with calibrated

portable instrumentType 2 & 3 0.2 pH units

Lower = 6.5 upper = 8.5

Lower = 6.0 upper = 9.0

TurbidityEPA 0180.1 and/or field

test with calibrated portable instrument

Type 2 & 3 1 NTU 250 NTU 500 NTU

SSCASTM Method D 3977-

9716

Type 3 if NEL is

exceeded5 mg/L N/A N/A

Bioassessment

(STE) Level I of (SAFIT),17 fixed-count of 600

org/sample

Type 3 LUPs > 30

acresN/A N/A N/A N/A

Required Field Equipment• Personal protection equipment (PPE) as required by the

inspector’s organization Health and Safety Plan– Latex Gloves– Safety Glasses– Hard hat and vest (per site requirements)– Proper shoes

• Sample collection device(s)– Sample collection pole or rope.– Dippers – Beakers– Sheet flow sampler

Required Field Equipment• Onsite testing equipment

– Handheld pH meter (e.g. LaMotte Model# 2020 or equivalent) – Handheld turbidity meter (e.g. Oakton Eco-Testr pH #WD-35423-10

or equivalent)Standard calibration solutions (per manufacturer’s instructions)

– Spare batteries • Other supplies

– Plastic squirt bottle for rinsing probes filled with distilled water – Lab wipes for blotting probes dry between uses

• Sampling jars and tubes (usually lab provided) if Suspended Sediment Concentrations (SSC) or other parameters are required.

Calibration and Use of pH Meter

• Proper calibration is required– pH measurements may be used for potential compliance or

enforcement actions,– Calibration should be carefully documented in the inspector’s

field log book. – Calibrate prior to each daily use

• Calibrating a pH probe typically requires three standard solutions of known pH. – Acidic pH=4, – Neutral pH=7, and – Basic pH=11

Calibration and Use of pH Meter

• Run the calibration program for the meter and follow the instructions to calibrate. – Immerse the probe in a solution when prompted to by the

program. – Probe should be clean prior to calibration, and rinsed clean and

blot dried between immersions into the calibration solutions. • Measurements

– Samples should be contained in a beaker or other approved sample container.

– Place the pH probe in the sample, above the bottom and away from the sides of the beaker and take a reading.

– Probe should be rinsed and blot dried between measurements. – Record the reading with information on the sample, date, time,

and construction site.

Calibration and Use of Turbidity Meters

• Inspectors should carefully follow the manufacturer’s instructions for the calibration and use of turbidity meters.

• Daily calibration prior to testing any site sample• Calibration typically uses a minimum of two standards

– Run the calibration program for the meter and follow the instructions to calibrate.

– Ensure that the calibration standard vial is clean and free of scratches, moisture, lint, or fingerprints which could impact the reading.

Calibration and Use of Turbidity Meters

• Measurements– Handheld turbidity meters typically require filling a glass vial with a

representative sample of the discharge– Make sure no bubbles are trapped in the sample vial and that the

outside of the vial is completely clean, free of scratches, moisture, lint, or fingerprints which could impact the reading

– Sample should be swirled prior to insertion into the meter so that it remains well mixed during the measurement.

– If the sample readings are outside of the calibration standard limits, recalibrate with a different standard

Calibration and Use of Turbidity Meters

• Measurements– If the sample readings are outside of the calibration standard

limits, recalibrate with a different standard– The sample vial should be rinsed between measurements and

blot dried with lab wipes– A field blank should be created by filling the glass vial with

distilled water after triple rinsing• Field blank measurements should be <0.1 NTU and • Conducted every 10 field measurements.

– The turbidity meter calibration should be re-checked for calibration drift, typically at the end of each day’s use

• Inspector should always diligently record the results of any field blanks, calibration, and standards measurements

Selection and Location of Effluent Sampling Locations

• The inspector should pay close attention to the following conditions or areas (hot spots) at a construction site that may cause sediment, silt, and/or turbidity in storm water discharges:– Exposed soil areas with inadequate erosion control measures;– Areas of active grading;– Poorly stabilized slopes;– Lack of perimeter sediment controls;– Areas of concentrated flow on unprotected soils;– Poorly maintained erosion and sediment control measures;– Tracking sediment onto roads and paved surfaces

• At minimum, the inspector should evaluate the site’s indicated sampling locations as valid and representative of the effluent, and sample at similar locations.

Receiving Water Monitoring

• Required at Risk Level 3 sites if a NEL is exceeded and there is a direct discharge to receiving waters. – Monitoring required for turbidity and SSC (if turbidity NEL

exceeded), and pH (if pH NEL exceeded). – Sampling is required upstream and downstream of point of

discharge in to receiving water. • Typically conducted by a water quality specialist retained by

the discharger. – The inspector should review the monitoring procedures and

verify that the procedures are being followed. – The inspector may want to collect a grab sample at the

monitoring location(s) to confirm that the discharger is accurately reporting the results

Bioassessments

• Typically will be executed by a specialty contractor, not covered in this training

• Required at Risk Level 3 sites where the ground disturbance is greater than 30 acres – Upstream of the project discharge – Downstream of the projects discharge– Any freshwater wadeable stream listed as impaired due to sediment– Any freshwater stream tributary to a water body that is listed as impaired

due to sediment

• The inspector might verify that:– The site meets the minimum criteria for requiring a bioassessment– Sampling locations are correctly located relative to the construction site– Proper bioassessment procedures and QA/QC procedures are being

followed