EPA Pretreatment 101CWEA P3S Conference

February 3, 2015

Sampling Plan –Standard Operating Procedures (SOP)

Type of sample (grab vs. composite)

Sample location Order of sampling Type of flow

measurement Parameter for analysis Sample volume Sample containers

Preservation techniques Sample identification

procedures Packaging and shipping Safety concerns Hazardous waste Chain-of-custody QA/QC procedures

Overlooked Items Field Log Book

pH meter calibration & documentation

Other measuring equipment? Conductivity meter Thermometers

Sampling Location Considerations

Is the sample “representative” ?

Is it safe, convenient, and accessible?

Is the IU and the POTW sampling at the same location?

Is it as outlined by the IU permit?

1124 Industrial Way

UltrasonicFlow Meter

Pipe 001Large 60NV

Trapezoidal Flume

DejaCorporation

Water Meter

+

Documentation of sample location. Have in IU file.

BEST: Include a picture of the sample location in the IU file.

Categorical Limit vs Local Limit

Categorical sample location is END OF PROCESS

Local Limit sample location is END OF PIPE

Types of Samples Time Proportional Composite: 24-Hour Time

Composite Interval time and sample volume constant Discrete Sampling set up- great for identifying pollutant

at particular time of day 24-Hour Flow Proportional Composite

Interval time and sample volume may vary Grab Samples

QA/QC samples (splits, duplicates, trip blanks)

Cyanide Hydrogen sulfide Fecal coliform

O&G pH VOCs Phenol

Continuous SampleAutomated collection and analysis of a parameter in a discharge

Typically used for pH and flow

Permit should define the conditions for a violation, significant noncompliance, etc…

Permit should define calibration requirements

Grab SamplesTaken from a wastestream on a one-time basis without consideration of the flow rate of the wastestream and without consideration of time

Compliance with instantaneous maximum Limits

Checking for extreme conditions.

Must be used to monitor certain pollutants (e.g., pH, volatile organics, oil & grease, cyanide)

On a case-by-case basis – may be used for monitoring batch discharges (is holding tank well mixed?)

Compositing Grab Samples

Pro Con

Does not identify the extreme conditions that exist

Lowers the analysis costs

Cyanide, total phenols, sulfides may be composited in the lab or in the field. VOCs and Oil & Grease may be composited in the lab.

When to use composite samples

Highly variable effluent (flow or pollutants) Categorical standards (generally) Permit that specifies daily maximum limits

Minimum volume of each sample? US EPA sampling guidance documents state that a

minimum of 100 mls. should be collected per individual aliquot

0

20

40

60

80

100

1 2 3 4 5 6 7 8

HOURS

FLOW

, gal

X 1

00

If an eight bottle discrete based sample was collected (one bottle per hour), a flow proportional sample could be prepared by using hourly flow data

24-Hour Flow Proportional Composite Sample Preferred!

Example…SIU discharges 70,000 gpd, however the flow varies. Some days 35,000 gallons of flow is discharged within 2 hour period. If time composite used (i.e. 100 ml every 15 minutes) then 8% of samples represented 50% of discharge.

Documentation of sample type used Sample type must be designated in the SIU permit If time composite is used, why is Control Authority

allowing this instead of flow proportional composite?

Time-Proportional vs. Flow-Proportional

40 CFR 403.12(g)(3):…Where time-proportional composite sampling or grab sampling is authorized by the Control Authority, the samples must be representative of the Discharge and the decision to allow the alternative sampling must be documented in that Industrial User file for that facility or facilities.

Document in the IU file why an IU is allowed to use time-proportional composite sample.

Flow Proportional Composite Set-up

Joe’s Chicken Factory discharges 24,000 gallons per day over a 24 hour period

Frequency of sample: every 400 gallons. Number of samples: 60 Volume per sample: 100 mls. {this would provide

6,000 mls (6.0 liters) for the composite sample.}

What if discharge volume increased to 36,000 gpd?

Field Situation

You set up a 24 hour flow proportional composite sample at Joe’s Chicken Factory. After 24 hours, you open the automatic sampler and find that the composite container has approximately 1,200 milliliters. The sampler was set to pull 100 mls every 400 gallons and the 24 hour total flow is 24,000 gallons….

What do you do?

Flow Measurement Installation & Monitoring Errors

Faulty fabrication of the primary device Improper gauge or head measuring location incorrect zero setting Improper head measurement Use of primary device outside its proper range Improper installation or maintenance of weirs Turbulence and surges in the approach channel

Calibration of Flow Measurement Equipment

IU Permit should have requirement on flow meter calibration

3rd Party calibration frequency and recordkeeping

Report all calibration procedures to Control Authority

Field Experience

Sample collection location

Temperature of a TSS sample

BOD5 vs CBOD5

Chain of Custody procedures

Analytical methods

Food Service Establishment

Average pH from Interceptor: 4.9 std. units (range 1.2 to 11.5)

BOD5 from monthly pumped interceptor with all components can be 500 to 1,000 mg/L

O&G from 20 to 2,500 mg/L

Violations…Of course it may be a violation, but some SIU’s may say “Lab error, the analysis result is wrong”;

but you need to investigate, it may be…

Chemical by-products New materials used New Supplier of raw materials or product Maintenance, cooling water, boiler chemicals Domestic Sources

Pollutant Sources• Review Industrial Waste Survey Results

– Chemicals known present, Chemicals suspected present• During Industrial User Inspections

– What chemicals are used and stored– What areas are chemicals used and why?

• Be familiar with chemical by-products• Be familiar with laboratory analysis interferences

Copper• Plumbing/piping

– Example: New copper water line at aquarium. Several rare fish species killed. Copper concentrations 4 mg/L to 6 mg/L

– Takes several months for residential copper piping to form biofilm to prevent high Cu leaching

– Hot water can cause more leaching (boilers, steam, industrial laundries)

• Controlling algae and aquatic plant growth• Paints, dyes – mildew resistance, biological control• Water resistant adhesives• Consider increased safety factor for Copper (& Zinc)

when doing local limits.

Zinc• National Avg Domestic Background: 0.231 mg/L• Oils, lubricants, greases• City water corrosion inhibitor (Zn polyphosphate)• Medicines, cosmetics

– One septic tank from residence had Zn concentrations > 1,000 mg/L

• Plumbing, piping• Anti-sticking agent (Zn stearate)

– Windshield wiper IU had increased Zn concentrations and ask if any processed changed, they said no. However, eventually found out that new rubber supplier had recently started.

Arsenic Wood preservatives Glass manufacturing Agricultural Products

Example: Arsenic product used to defoliate cotton. Problems at clothing mfr. Problems with corrugated box mfr. (potatoes – starch

contamination)

Molybdenum Lubricating oils Smoke suppressant, used in some plastics Foods (nitrogen fixing agent assisters- beans, peas,

etc..) Corrosion Inhibitor

Cooling water additive Different forms, look for sodium molybdate. Concentrations may range from 2 to 20 mg/L

Total Phenols• Resins used in Plywood adhesives, wood preservatives

– Landfills can have elevated phenols• Disinfectants, deodorizers

– Automobile mfr had chronic phenol violations. Over 1 yr of research and sampling conducted. Identified disinfectant/deodorizer.

• Air Masking Agents– Sweet smelling aroma. Pentachlorophenol

contamination in WWTP sludge• Antiseptics, Lotions, Lozenges

Organics Chloroform

IU did not use chloroform but had concentrations > 14 mg/L

By-product of chlorination Phthalates

Do not use plastic containers when sampling, and use Teflon tubing not Tygon

Other Volatile Organic Compounds

Toluene, Benzene, Trichloroethylene, MEK, and other solvents or cleaners Industrial laundries can have clients that send them

solvent rags to be cleaned Identify the source of the solvent rags sent to the

industrial laundry, this may identify another Industrial User.

Ammonia Seasonal Variation

Expect significantly higher concentrations of ammonia in the summer (temp, urea, etc…)

Septic conditions can lead to higher concentrations Sewage pumping stations

Cooling additive At higher pH, ammonia is more toxic, and ammonia

can be stripped from wastewater.

Hydrogen Sulfide Force main discharges

Higher concentrations due to temperature increases, pH changes and retention time (longer with no Infiltration/Inflow to collection system)

Below food service establishments Certain industrial users with high sulfate or sulfide

concentrations, or can have very high BOD5 or low oxygen content to ww

H2S – Hydrogen Sulfide

Industrial Corrosion

Part of Industrial Pretreatment Sampling is to be aware of the varying conditions at the IU, and potential impacts to the collection system.

Industrial User Corrosion Corrosion impact may be further downstream than

immediate downstream manholes. CCTV

Dairies Bottling operations Metal finishers

Corrosion Hydrogen Sulfide-anaerobic decomposition of sulfate

FOG can contribute to sulfide formation in sewer pump stations and in collection system

Also, sulfate can react with calcium in concrete to form calcium sulfate, which can cause concrete to crack

Chloride Can cause decay and penetrate coatings

Chlorine HCl and HOCl can increase rate at which iron and steel corrode

Nitrates and Nitrites Can contribute to iron and steel corrosion

Dissolved Salts Electrolytic action on base material can corrode concrete, cement

mortar Organic Compounds

Solvents will promote the dissolution of gaskets and rubber and plastic linings

FOOD SERVICE ESTABLISHMENT -Grease Interceptor deterioration, baffle wall collapse, leaking, and corrosion impact to public sewer

Other sources of corrosion*Food Service Establishments

*Coffee Shops

(coffee pH 4.6 to 5.1)

*Bakeries, FSEs with high sugar use

Industrial Users: Dairy products, colas

Work with Collection System Support & Preventive Maintenance Personnel

Sewer corrosion below a coffee shop

Infiltration & Inflow Prevention Effects

Some WWTPs have experienced a dramatic increase in pollutant concentrations when the collection system has been repaired to prevent I & I.

In some cases, the WWTP has blamed an IU for the elevated concentrations in pollutants, so recommend doing some residential and commercial background sampling to identify pollutant concentrations.

Questions, Comments?