NYC DEP Bureau of Water Supply, Water Quality Division of Science and Research Giardia and Cryptosporidium Monitoring in the New York City Watershed A Retrospective Kerri Alderisio Watershed Science and Technical Conference September 17, 2008West Point, N.Y.

“The Conference will bring scientists, engineers and technical experts together with watershed stakeholders and the public, to technically inform and present leading- edge research findings on information collected to date, with regard to the protection of the nation’s largest unfiltered surface water supply.” WSTC brochure

Outline  Are they out there?  Method History  If so, how many?  Data Review  Are there any trends?  Giardia  Are they harmful to people?  Additional Research

Are they out there? An accurate, reproducible, validated, approved method is paramount to answering this question… Methods for protozoan recovery have undergone many changes over the past 20 years…

DEP Protozoan Method History (16 years; 3 methods; 3 laboratories) YearsMethodsDetailsLaboratory 1992 – 1999 (lowest recovery) ASTM 1000L Spiral wound nom. Filter, PSF, well slide NYS DOH / ECWA 1999 – Oct 2001 (20-30% recovery) ICR 100L Spiral wound nom. Filter, PSF, Hoef. man., filter on slides NYC DEP Oct (50-75% recovery) 1623HV 50L Envirochek abs. filter, IMS, spot on slides NYC DEP

Method 1623 – Collection & Analysis

IMS Technology

Other Method Improvements: Pressure and NaHex Experimental Results 56% 18% 45% 12% 39% 1% n=8

Stain Experiment Easy Stain Avg. Giardia/ 50L MerifluorEasyStain Giardia Detection %45%

Stain Differentiation Results P. Wallis, Hyperion G. muris Same lot # G. intestinalis

Colorseed Experiment (FITC & TR) Damaged cysts Faded FITC Subjective Texas Red

Recovery Comparison DEP 1623 and DEP ColorSeed Method

How many are there ?  Upstate Keypoints  Kensico Streams  Terminal Keypoints

Giardia at Catskill Sites Combined Giardia at Delaware Sites Combined

Cryptosporidium at Delaware Sites Combined Cryptosporidium at Catskill Sites Combined

Upstate Key Point Mean Values ReservoirGiardia In Giardia Out Crypto In Crypto Out Cannonsville Pepacton Neversink Rondout Schoharie Ashokan

Giardia at Eight Kensico Perennial Streams

Cryptosporidium at Eight Kensico Perennial Streams

DEL18 Giardia

CATLEFF Giardia

Cryptosporidium DEL18CATLEFF

Down the Pipe! GiardiaCryptoGiardiaCrypto RDRRCM CATEARCM DEL CATALUM DEL CATLEFF Results are per 50L, US EPA Method 1623 Data from October 2001 – August 2008 Arrows indicate flow

CLGH Giardia

NYC Source Water Cryptosporidium LT2 values

Are there any trends?  Temperature  relationship  1623 stain study  Merifluor  Easystain

Giardia and Temperature DEL Easy Stain Year

Mean Giardia at CATLEFF by season YEAR W Sp Su F W W W W W Sp Su F F F F W Avg. = 3.04 =0.54 Easy Stain year

Are they harmful to humans?

Storm Samples Wildlife Feces Storm Sites –3 streams –~121 samples ( ) Genotypes –22 Cryptosporidium genotypes found Significance –98%+ not significant human pathogens –Most prevalent = deer, rodent, muskrat, skunk Animals –38 different species –541 specimens ( ) Prevalence –111/541 (20%) positive –21 genotypes were found (11/ 21 previously seen in DEP storm water) –6/11 previously unknown –4 novel genotypes! –4 expanded hosts!

DEP data up to April 2004 indicate wildlife contribute to Cryptosporidium contamination in stream storm water, but have no major public health significance in cryptosporidiosis

Conclusions Are they out there? –Yes, and we have a good, improved method How many are there? –Not a lot, source water is: ~ 2.0 Giardia / 50L ~ 0.2 Crypto / 50L Are there any trends? –Yes, Giardia low summer/ higher winter; not enough Crypto detected to be certain Are they harmful to humans? –Not significant human pathogens ( )

Thank You! Acknowledgements: S. DiLonardo C. Pace WQ Pathogen Laboratory staff WQ Field staff