Introduction and Importance of Reuse/Recycle Water and the

© year IDEXX Laboratories, Inc. All rights reserved.

Introduction and

Importance of

Reuse/Recycle Water and

the Use of Defined

Substrate Technology for

the Detection of Indicator

Bacteria Gil Dichter

World Wide Technical Support Manager, Water

[email protected]

1 © year IDEXX Laboratories, Inc. All rights reserved.

OBJECTIVES Introduction to Reuse Water

Importance of Reuse Water

Where is it being used?

Review of studies comparing Traditional

Methods to Colilert

Q & A


- Drought

- Population growth

- Increased municipal, industrial, and agricultural demand

- Dependence on single source of supply

- Restrictions on wastewater discharges (nutrient limitations)

Factors Driving Water Reuse

2

Water

scarcity



Observations for Water Reuse


Guidelines for Water Reuse

EPA/625/R-04/108 Sept 2004 EPA 600/R-12/618 Sept 2012


Categories of Water Reuse Applications

• Many states have rules, regulations or

guidelines for the range of reuse water

• Urban Reuse for non-potable applications.

• Agricultural Reuse

• Impoundments (recreational waters)

• Industrial Reuse


Reclaimed/ Reuse Water

- Wastewater that has been treated to meet specific

water quality criteria used for a range of purposes

• Requirements for microbiological and chemical

parameters

- Varies from state to state (majority of states test for

fecal coliforms followed by total coliforms and several

for E.coli

Bacteria - total or fecal coliforms, E.coli or

enterococci

Pathogens - Cryptosporidium, Giardia, viruses

Chemistry: pH, Turbidity, BOD, COD, TSS


Potential for Water Reuse

• About 7% of municipal wastewater effluent in the U.S. is reclaimed and beneficially reused

• Israel reuses more than 70%

• Singapore reuses 30%, up from 15% in recent years

• Australia, now at 8%, has a national goal of 30% by 2015

8

~7.3% Reclaimed

About 33 BGD of municipal effluent is produced annually in the U.S.


Wastewater

Treatment

Drinking Water

Nonpotable Reuse (NPR)

Customers

Raw Water

Sources

Nonpotable Users

Irrigation

Industry

Cooling

Towers


Wastewater

Treatment

(often with some

advanced treatment)

Water Treatment

Drinking Water

Indirect Potable Reuse (IPR)

Customers

Other Water

Sources

“Environmental

Buffer”


Wastewater

Treatment

Water Treatment

Drinking Water

Direct Potable Reuse (DPR)

Customers

Other Water

Sources

Advanced

Treatment

X


• Bacteria Indicator- E.coli

• Bacterial Limits:

- 30 Day Geometric Mean: 11/100 mL

- Reportable violation: 35/100 mL

- Uses: recreational areas - parks, golf

courses

Reuse Water- Virginia

Microbiological Methods


Multiple Tube Fermentation

Methods

Membrane Filtration

Enzymatic Methods

(Colilert & Colilert -18)


Multiple Tube Fermentation


Membrane Filtration

• Place filter on filter assembly

• Pour sample

• Apply vacuum

• Rinse filter assembly

• Remove filter and transfer

onto agar plate

• Cap, invert, and incubate


Defined Substrate

Technology- Colilert or

Colilert-18 and Quanti-Tray

Quantification


Procedure for either P/A or Quantification

Blister Pack Add Reagent to Sample


Mix well to Dissolve


Quanti-Tray

Pour sample into Quanti-Tray Seal Quanti-Tray


Incubate

Temperature

• Fecal Coliform

44.5°C ± 0.2° C

Total coliform/E.coli

35 ± 0.5° C

Time

• Colilert: 24 hours

• Colilert-18: 18 hours


Incubator - Water bath


Positive Yellow Wells for Total

Coliforms or Fecal Coliforms


E.coli- Blue Fluorescence- Quanti-Tray

under a 365nm UV Light


Quanti-Tray 2000 MPN Table

No of large

wells giving

positive

reaction

No of small

wells giving

positive

reaction

MPN per

100ml

sample

95% Lower

Confidence

Limit

95% Upper

Confidence

Limit

10 2 13.2 7.1 22.0

30 12 64 46.8 85.1

47 40 509.9 393.4 652.5


Quanti-Tray 51 MPN Table

No wells

giving

positive

reaction

MPN per

100ml

sample

95% Lower

Confidence

Limit

95% Upper

Confidence

Limit

0 <1 0 3.7

15 17.8 10.8 29.4

35 59.1 42 84.4

51 >200.5 146.1 infinity


Studies

• California -

• Florida

• Oregon

• Idaho

• Washington


Protocol for Comparing Methods

and Review of Several Studies


Collect 250 ml sample

100mL for Colilert /Q-Tray-

Lab Method

100 mL for

MF or MPN

Incubate samples for required time & temperature

Read and record results


California- Title 22

Requirement for Total Coliforms

• Total coliforms is the indicator bacteria required

for testing reuse water

- MTF 15 tube for total coliforms

- 2.2/100 mL 7 day median (if 4 consecutive days exceed

this, then 4th day is in violation)

- 23/100 mL not to exceed in more than 1 sample in a 30

day period

- 240/100 mL maximum for any one sample


Site A • Secondary treatment for final effluent using

chlorination

• Samples tested over a 2 month period with n = 33

• All samples were tested in duplicate

• Positive & negative QC controls tested weekly

• All positive controls were within assigned range

• Negative controls were negative


Site A 2X2 Table con’t

All results LTB-BGLB

Colilert + - Total

+ 3 11 14

- 0 52 52

Total 3 63 66


Site A Tests Results Summary

LTB-BGLB

• 3 positives at 2/100

mL

Colilert


mL


mL


Site B

• Tertiary treatment for final effluent using UV at

one plant and chlorination at the other plant

• Samples tested over a 1 month period

• Positive QC controls tested weekly

• Spiked sample tested

• All positive controls were within assigned

range


Site B 2X2 Table con’t


Colilert + - Total

+ 0 3 3

- 1 16 17

Total 1 19 20


Site B Tests Results Summary UV Plant

LTB-BGLB

• 1 positive at 1/100

mL

Colilert


ML


mL


Site C • Tertiary treatment for final effluent using

chlorination

• Samples tested over a 2 month period with n = 25

• Positive spiked control diluted in reuse water

tested weekly

• All positive controls were within assigned range


Site C 2X2 Table con’t


Colilert + - Total

+ 0 0 0

- 0 25 25

Total 0 25 25


LTB-BGLB

Colilert + _ Total

+ 3 3 6

- 3 2 5

Total 6 5 11

Site X, OR 2 X 2 Table


• 11 samples tested in parallel between Early May and mid-

August.

• Positive QC controls were tested and all were within the

assigned range.

• Reuse water spike with the positive control.

• PT was completed and passed.

• Results in 24 hours vs. 48-96 hours.

• Approval recommended by Certification Officer and permit

office issued permit action letter to allow use of Colilert.

Site X, OR


Final Conclusions • Parallel testing at these sites indicates no significant

difference between the methods.

• Results can be obtained in18 or 24 hours compared to 48-96

hours

• Data from the sites suggest that Colilert can be used for

testing reuse water.

• Facilities in CA approved for using Colilert.

• Florida site using it for the past 2 years.

• Approved in Oregon. Can now use Colilert without further

approval. Same is true for Washington.

•Idaho Pending


Questions

Documents

Introduction and Importance of Reuse/Recycle Water and the