The Dirty Dozen:Pending Regulation of Chemical and Microbiological Constituents in Our Drinking Water

SCSRA 26th Annual MeetingMay 30, 2012

Edgar G. DymallyWater Quality SectionMetropolitan Water Districtof Southern California

The Metropolitan Water District of Southern California

• Wholesaler• Provide supplemental water through 26 member agencies to a population of 18 million in southern California

• Sources (Surface Water)• Colorado River and State Water Project• Import ~2.2 MAF/yr

• Acre‐foot = 325,851 gallons; annual needs of two families

• Water Distribution• Treatment capacity: 2.5 BGD [30 Rose Bowls]

• Enough water to fill Yosemite Valley at a depth of 2 ft/day

Major Source WQ Issues

California Aqueduct

ColoradoRiver Aqueduct

BromideTOC

ArsenicNitrate

Taste & odorAlgal toxins

Salinity Perchlorate Chromium Radionuclides Nutrient/pathogen

Organic & Inorganic Chemicals = 28 Million

Commercially Available = 10 Million (35%)

Inventoried or Regulated = 240,000(0.9%) ? 120 (~0.0004%)

The “Known” Chemical Universe*

*Adapted from Christian Daughton, Ph.D.; EPA

Where We Are Today—The Number of Regulated Contaminants

NIPDWRTTHM

Phase I

Phase II & LCR

Phase V Stage 1 D/DBPR

Rads

0102030405060708090

100

1976 1979 1987 1989 1991 1992 1995 1998 2000

SWTR & TCR

Water Quality PhilosophyWater Quality Philosophy

Source Protection

Treatment Effectiveness

DistributionIntegrity

The Budget

• Who has seen a revenue drop?• It’s going to get ugly

• From the federal level

• We are facing a “fiscal cliff”• “Sequestration” budget cuts• Expiration of tax cuts

• “Sequestration” cuts are the results of the 2011 budget deal• “Backstop” – Super committee was supposed to solve• 7.7%‐7.8% reduction in spending across the board

The Budget (cont.)

• Expiration of the tax cuts• Decreases in Social Security withholding and personal income tax percentage• Will impact 90% of households• Cost an average household $3,500

• Congress has difficulty passing a budget• Zero appropriations bills• Federal government operating under a Continuing Resolution (CR) until March 30th

• Nobody wants a government shutdown during an election 

The Budget (cont.)

• The one certainty for 2013: Federal funding is going to decrease

• Many existing programs will be cut• New spending will be extremely difficult

Pending Regulation of Chemical and Microbiological Constituents

• Chromium 6• Perchlorate• Fluoride• Arsenic• Nitrate• Carcinogenic VOCs• NDMA and Nitrosamines• 1,2,3 Trichloropropane• 1‐4 Dioxane• Cyanobaterial Harmful Algal Blooms

Hexavalent Chromium (Cr-6)

• Total chromium regulated in 1991 at 100 ppb• “Erin Brockovich” increased interest in Cr-6• Draft risk assessment now in late 2013

• Final risk assessment thereafter• EPA will have to then decide if regulation needs to be

revised to address Cr-6 (a likely outcome)• Not sure if this would be part of SY3 or an “out-of-

cycle” regulatory determination

• Total and Cr-6 included in UCMR3 monitoring• Relationship between the two can vary quite a bit

• Treatment is challenging and expensive• Total treatment costs for a potential Cr-6 regulation

could be higher than all SDWA regulations to date

EWG Report – December 2010

Perchlorate Background

• Oxidizer used in solid rocket propellant, munitions, and fireworks 

• Sources of contamination• Improper disposal of waste• Accumulation in food (milk, vegetables)

• Health effects• Interferes with thyroid’s ability to uptake iodide• May affect normal metabolism, growth, and development 

• Pregnant women and infants are most susceptible

Revised Perchlorate Public Health Goal

• On January 7, OEHHA proposed lowering the existing PHG for perchlorate from 6 ppb to 1 ppb

• After reviewing comments, OEHHA will determine the final PHG

• In 2007, CDPH set a drinking water standard of 6 ppb, (the same as the PHG)

• If the PHG is lowered, CDPH would reevaluate the existing standard

• Since 2006, source water levels of perchlorate entering MWD’s system have averaged approximately 2 ppb or less

Fluoride

• 2006—NRC Report recommended review of 1986 MCLG (and ultimately the MCL)

• March 2010—EPA’s second six‐year review• January 2011—Joint HHS/EPA actions

• HHS proposed 0.7 mg/L as optimal level• EPA released technical analyses

• HHS will finalize its recommendation soon• AWWA commented on the small gap between optimal 

fluoride level and potentially lower MCL and the need to recognize an operational range

• EPA will decide if MCLG/MCL needs to be revised after risk assessment completed (completion date not clear)

Arsenic and Nitrate

Arsenic• Arsenic is ubiquitous in

nature and is commonly found in drinking water sources

• Residuals from treatment are expensive to handle

• Known human carcinogen

• MCL 10 ppb

Nitrate• High levels particularly

in the Central Valley are prompting action by EJ community

• Acute risk similar to perchlorate

• MCL 45 ppm

Carcinogenic VOCs (cVOCs)

• Feb. 2, 2011 – EPA Administrator Jackson announced Carcinogenic VOCs (cVOCs) as the first group to be regulated• Proposal likely in late 2013

• Final rule likely in 2015• Eight currently regulated VOCs were identified, as

well as eight VOCs from the Third Contaminant Candidate List (CCL3)

• Another important consideration• Second six-year review in 2010 concluded that

MCLs for TCE and PCE should be revised

Potential cVOC Rule• Second six-year review (2010)

• MCLs for TCE and PCE should be revised• Both currently have MCLs of 5 ug/L (ppb)

• Zero MCLG and improved analytical method drove EPA analysis of MCLs of 1 ppb or 0.5 ppb

• EPA’s analysis of potential MCLs of 0.5 ppb concluded that approximately 400 (?) systems would be impacted

• Lower TCE/PCE MCLs would likely remove some of the eight unregulated CCL3 VOCs• TCP is the biggest concern amongst the eight

unregulated CCL3 VOCs

N‐Nitrosodimethylamine (NDMA) and Nitrosamines

• Disinfection by‐product of drinking water treatment• U.S. EPA considers several nitrosamines to be 

probable human carcinogen• Found at very low concentrations

• A few nanograms per liter (ng/L), or parts per trillion

• A treatment technique may likely be proposed as a standard versus an MCL

Nitrosamines

• Nitrosamines meet the first two of the three SDWA criteria for regulating a new contaminant• NDMA and other nitrosamines are carcinogens• NDMA and other nitrosamines occur (UCMR 2 data)

• Meeting the third criteria is debatable• Drinking water contribution is small

• Larger contribution from food and from what is produced inside the body (endogenous)

• Drinking water contribution is less than 0.1%

• EPA is under pressure to regulate “something”• The preliminary third regulatory determination will 

likely be delayed past the November election

1,2,3 Trichloropropane (TCP)

• California Notification level of 5 ppt• Subject of recent groundwater litigation• Subject of potential California legislation• California Dept. Public Health has indicated potential 

regulation

1,4 Dioxane

• Considered a carcinogen• CA PHG at 3 ug/L (1/million risk)• Draft revised EPA risk assessment estimates risk 17x 

worse• No EPA or state MCLs for 1,4‐Dioxane• EPA lacks occurrence data• Likely lack enough information to go forward• Used as a stabilizer• California Notification level of 1 ppb

Cyanobacterial Harmful Algal Blooms (CyanoHABs)

Significance of Algal Toxins

• Implicated in cases of human illness over many years.

• Have caused deaths of livestock, waterfowl, dogs, & some people.

• Worldwide in occurrence.• Some toxins known to be tumor promoters.

• Possible link to liver cancer in China.

Microcystin Producing Cyanobacteria

Microcystis aeruginosa

Anaebaena

circinalis

Planktothrix agardhii

Nostoc sp.

Where We Are Today with Regulations

• EPA finalized 18 drinking water regulations between 1975‐2006• Nine prior to 1996 SDWA Amendments

• NIPDWRs, Fluoride, TTHMs, VOCs, TCR, SWTR, Phase II & V Rules, and LCR

• Most regulations based on numerical MCLs using annual average of quarterly samples

• Nine after 1996 SDWA Amendments• Arsenic, Radionuclides, FBR,  and M/DBP Cluster

• M/DBP Cluster – Stage 1 and 2 DBPRs, IESWTR, LT1 and LT2ESWTRs, and GWR

• Generally more complex regulations• Last new contaminant regulated was uranium in 2000

J. Alan Roberson, P.E.Director for Federal RelationsEmail: aroberson@awwa.orgDirect: (202) 326‐6127

Edgar G. DymallyMetropolitan Water Districtof Southern CaliforniaEmail: edymally@mwdh2o.comDirect: (213) 217‐5709