www.eatonanalytical.com

The SDWA

Perspective on

Pesticide Analysis

Andrew Eaton, Ph.D., BCES Lab Technical Director

Eurofins Eaton Analytical Inc. Monrovia, CA 91016

Presentation Outline

A brief history of drinking water standards and methods

General trends in methods

Impact of new technologies

UCMR3 – Harbinger for the future for SDWA?

The future?

2

A Global Perspective on Standards

• US drinking water standards (and hence methods)

have historically focused on health limits (also a

regulatory requirement)

• EU standards have focused on the “precautionary

principle” and used “group” concepts

• WHO standards have focused on health, but not with

the same constraints, but also considered emerging

contaminants

So typically regulatory limits are WHO > EPA >> EU

# of analytes with regulatory limits EPA > WHO >> EU

3

US Drinking Water Methods Did Not Start

Out Focused on Ultra-Low Levels

4

• Current regulations for drinking water

quality essentially became important

with the Public Health Service and

were predominantly inorganics.

• Methods came from Standard Methods

• The Safe Drinking Water Act, first

promulgated in 1974, authorized EPA

to set standards AND specify methods.

1974

Safe Drinking Water Act (1974)

5

Drinking Water Standards- 1975-2000

• 1976 – Radionuclide

regulations

• 1979 – THM regulation

• 1986 – the 83

contaminants….

(also mandated EPA to

regulate 25 new

contaminants every 5

years)

• 1996 – Set the framework for

the concept of the UCMR

(requiring utilities to monitor

and report unregulated

contaminants of public

health concern)

6

Number of contaminants regulated

under the SDWA

SDWA Regulatory Process

Current Approach

1996 SDWA Amendments

Plan-Do-Check-Act

Contaminant Candidate List (CCL)

CCL1 – March 1998 (60 contaminants)

Unregulated Contaminant Monitoring Rule (UCMR)

UCMR1 – Sept. 1999 (26 contaminants)

7

SDWA Regulatory Process

-Opportunities for Impacting It

Draft CCL

Final CCL

Final Rule

(NPDWR) 6-Year Review of

Existing NPDWRs No further action if make

decision to not to

regulate (may develop

health advisory).

Preliminary

Regulatory

Determinations1

Final Regulatory

Determinations

Proposed Rule

(NPDWR) Draft UCMR

Final UCMR

UCMR Monitoring

Results

9

EPA is required to develop an MCLG and MCL for a

contaminant if the Administrator determines that:

1. The contaminant may have an adverse human health effect

[CCL]

2. The contaminant occurs or is likely to occur in drinking

water at a level of public health concern [UCMR]

3. Regulation of the contaminant presents a meaningful

opportunity for health risk reduction [Regulatory

Determination]

Three Criteria Used to Determine

Whether or Not to Regulate

USEPA Analytical Methods 1975- 2000

• 1970s – Main source of methods was Standard Methods

• 1979-1983 - Manual for Chemical Analysis of Water and

Wastes

• Essentially an inorganic methods manual

• 1987 – First EPA methods for DW organics (VOCs)

• 1992-95 – First EPA DW methods for SemiVoa/Pesticides

• 1994-2000 – Updates to Inorganic Methods and elimination

of many old methods

10

2000 to the Present – Game

Changing ERA

Drinking Water Standards

• Information Collection Rule

• UCMR1 (2001-2005)

• UCMR2 (2008-2010)

• UCMR3 (2013-2015)

Analytical Methods

ppb levels of DBPs

Perchlorate at 4 ppb MRL. MRLs

for Compounds HRL driven

(example: nitrobenzene)

LC-MS-MS and GC-MS-CI

methods introduced, but only

nitrosamines at sub ppb levels

Almost entirely sub 0.1 ppb MRLs

Method sensitivity driven

11

UCMR1 – Limited Pesticides and

“High” MRLs

• USEPA 525.2, USEPA 515.4,

• All routine in drinking water labs

• MRLs in the 0.5 ppb and up range

• USEPA 526,

• New method, but still reasonable (ppb) MRLs

• Note: Lots of “non pesticides” in UCMR1

12

UCMR1 - Results

• We saw DCPA (Dacthal) commonly (~5% of systems),

but at levels well below WELL ESTABLISHED health

reference levels

• Nobody really cared….

• EPA made a conscious decision to NOT regulate

DCPA

• All the other pesticides

• Essentially no detects

13

UCMR2 Pesticide Methods, MRLs,

Results

• Almost all brand new methods

• 525 (again), 535 (first LC-MS-MS method),

• but still ppb range reporting limits

• 525/535 paired to look for degradates

• EXPECTED to see acetanilides and degradates frequently

• MRLs set at 1 to 2 ppb, based on HRLs

• But the ONLY thing EPA really saw were nitrosamines

• mainly NDMA in >25% of systems

14

Acetanilides: the Impact of MRL AND

Sampling Period Selection

15 Data from Delzer (ASDWA, 2012)

In contrast, UCMR2, with MRLs of 1-2 ppb, had <0.1% detects of these

compounds, but the degradates did represent 90% of the hits

Changes in Perspective for UCMR3

• Low frequency of detects for UCMR1 and UCMR2

• Why are we monitoring non-detects?

• Results for acetanilide herbicides were counterintuitive

• Wrong compounds? Or wrong levels? Or wrong

frequency?

• EPA opted to focus on the “wrong levels” issue

• Hence UCMR3 changed from being HRL driven to

being MRL driven (mostly…)

16

Another Factor Influencing

Where EPA is Going

• Development of the LCMRL concept to

establish reporting levels

• Minimizing the DL/MDL for SDWA compliance

• But making MRLs much more rigorous in

determination

• PIR concept

• Validation daily

17

UCMR3 Analytes – Generally

Method Driven Limits

• Metals by 200.8 - 0.2 to 1 ppb MRLs (prior 1 – 10 ppb)

• Hexavalent chromium – 0.03 ppb MRL

• 1,4-Dioxane – 0.07 ppb MRL

• VOCs – 0.03 to 0.2 ppb MRL (current 0.5 ppb)

• PFCs – 0.01 to 0.09 ppb MRL (methods can go lower…)

• Hormones – 0.0001 to 0.0008 ppb MRL

• Chlorate – 20 ppb MRL

NOTE THAT ARE ACTUALLY NO PESTICIDES IN UCMR3

18

UCMR3 MRL Comparison with

UCMR1/UCMR2 MRLs

• For organics the UCMR3 MRLs are

`100-1000x LOWER than UCMR1&2 (except nitrosamines)

• For metals the UCMR3 MRLs are

10-100X lower than perchlorate in UCMR1

• Only chlorate has a “high” MRL

• i.e. > 1 ppb

19

So What Do the Low MRLs Mean?

• As chemists we know there is no such number as “0”,

so there is an inherently greater likelihood of detection

as we look lower.

• How much greater is the critical question

• Do the health effects numbers justify looking this low?

• Will this provide communications challenges?

• Are the lessons we learned in geochemistry and

oceanography relevant for new methods?

• As we go lower, can we truly trust the results?

20

New SDWA Methods – Continuing the

Trend of Trace Contaminants…

• Most of EPA’s methods development work in the last 5

years has been focused on:

• Pushing MRLs much lower (e.g. 522, 524.3, 539)

• Using LC-MS-MS direct injection or SPE

techniques to identify less volatile compounds

• 536 (triazines and degradates) 50 ppt….

• 537 (PFCs) 10-100 ppt…

• 538 (organophosphates) 50-500 ppt…

• 539 (hormones) 0.1-1 ppt…

• 540 (CCL3 organics) 10-100 ppt…

21

Other Things in the Works at EPA for

Drinking Water

• It generally takes EPA 2-3 years to develop and finalize a

method, particularly when they are trying to respond to

requests for increased flexibility.

• Recent UCMR4 stakeholders webinar demonstrated

some of this development

• Reaching out for comments to chemists

• But not always receptive to comments…

22

Challenges as We Go Lower

• Instrument sensitivity is not a real issue

• The LCMRL is a good concept in PRINCIPLE

• But defining “MRLs” is…and EPA still doesn’t have

that as rigorous as it might be…

• Samplers are not trained on proper precautions

• Lessons from oceanography…

• Many drinking water labs are not used to these levels

• Potential for blank contamination

• UCMR3 will give EPA a feel for how labs do at these levels

23

Analytical Technology is Truly Driving

Drinking Water Evaluation

1.E-22

1.E-21

1.E-20

1.E-19

1.E-18

1.E-17

1.E-16

1.E-15

1.E-14

1.E-13

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1960 1980 2000 2020 2040 2060 2080 2100

History of Detection Limits

mg/L

µg/L ng/L

pg/L One molecule

per liter in 2090

But, surely there is

a point where it

means nothing

It also means we

can’t afford to keep

up by buying more

and more treatment –

or more and more

expensive

instruments…

courtesy of Dr. Rhodes Trussell

Conclusions

• As analytical methods have improved, our “goals” as far

as identifying contaminants have improved.

• And the public becomes more “aware”

• EPA SDWA perspective has also “changed the rules” in

that analytical methods (and “groups”) seem to now be

driving regulations rather than health effects.

• With the reduction in minimum reporting levels, the

frequency of detection will increase (UCMR3 already

demonstrates that) and labs will have to be sure results

are dependable and defensible.

25

Any Questions?

Dr. Andy Eaton

Technical Director

andyeaton@eurofinsus.com

Eurofins Eaton Analytical, Inc.

www.eatonanalytical.com

750 Royal Oaks Drive

Monrovia, CA 91016 USA