Cryptosporidium Monitoring for Compliance with the LT2 Rule

Report
Cryptosporidium
Monitoring for
Compliance with the
LT2 Rule
Tim Stefanich - Environmental Engineer
Sioux Falls Water Purification
What do I need to do to prepare?
• Are you required to sample?
– All SW and GWUDI systems must sample
System Size and
Type
Monitor For
Filtered Systems > Cryptosporidium
10,000
E. Coli
Turbidity
Filtered Systems
< 10,000
Frequency
Duration
1 per month
24 months
E. Coli*
2 per month
24 months
Cryptosporidium
1 per month
2 per month
24 months
12 months
*E. coli results may trigger Cryptosporidium monitoring. If annual mean
E. coli > 10 / 100 ml when using lake / reservoir then must sample for
crypto. If annual mean E. coli > 50 / 100 ml when using flowing stream,
then must sample for crypto. (SWM GM table 1-1)
What do I need to do to prepare?
• When do I begin to sample?
System that serve….
Must begin the first round of sampling no later
than the end of:
At least 100,000 people
October 2006
From 50,000 to 99,999
people
April 2007
From 10,000 to 49,999
people
April 2008
Fewer than 10,000 and
monitor for E. Coli
Fewer than 10,000 and
monitor for Crypto
October 2008
April 2010
What do I need to do to prepare?
• Obtain a copy of the rule (153 pages)
• Obtain EPA Guidance Manuals
– Surface Water Monitoring GM (151 pages)
– Microbial Laboratory GM (273 pages)
• Obtain list of EPA approved labs
• EPA Crypto and e-coli sampling pocket guide
• State Point of Contact – Mark Mayer
http://www.epa.gov/ogwdw/disinfection/lt2/
index.html
Guidance Manuals
• Surface Water Monitoring GM
– Setting up contract for lab services
– Sampling location and schedule
– Collecting and shipping
– Grandfathering
– Reviewing and submitting data
• Microbial Laboratory GM
– Laboratory analysis methods
– How to receive laboratory approval
Research Cryptosporidium Sampling /
Testing Methods
• Method 1622 – Cryptosporidium in water
• Method 1623 – Cryptosporidium and
Giardia in water
– LT2 Rule does not require monitoring for or
reporting of results for analysis of Giardia.
– Little additional cost for Giardia analysis
– Sampling requirements are identical between
methods
• Must use an EPA approved laboratory
Research Sampling Procedures
• Collect and ship bulk water samples
– Sample size (10 – 50 liter)
– Shipping costs
– Extra cost for lab to filter sample
• Filter sample on-site and ship filter.
– Purchase own equipment?
– Rent equipment?
– Type of filter used?
– Suggest spare equipment and filters
Filter Sample On-Site
• Two types of filters approved
– IDEXX Filta-Max
• Less expensive
• Separate filter and holder
• Tolerant to higher pressures
•
(< 120 psi)
Flow rate 3 – 4 L/min
Filter Sample On-Site
• Envirochek or Envirochek HV
– More expensive (2X)
– Integrated filter and holder
– Less tolerant to higher pressure
• 30 psi for Envirochek
• 60 psi for Envirochek HV
– Higher flow rate for HV
• 2 L/min for Envirochek
• 4 L/min for Envirochek HV
• Some labs may be specific as to the type of filter
used.
Sample Size
• Minimum 10 Liter sample
– Highly turbid samples may require more than
1 filter to get minimum 10 liters.
• Recommend that sample size be
consistent through the sampling period
Sampling Frequency
• Matrix spikes
– Required at least every 20 field samples
– Used by lab to “spike” with Crypto, filter, and
analyze to determine recovery within your
source water.
– Allowed to pre-filter any sample over 10 liters
and shipping filter and remaining 10 liters for
“spiking”
– Sample taken same time or right before or
after as regular crypto sample.
Sample Collection Location
• Source water prior to any chemical addition,
treatment, or addition of backwash water
– Multiple sources may require volume weighted
samples
Ex. Source A = 25%
Source B = 75%
Volume Weighted Sample (one 10L Sample)
Volume A = 2.5 L
Volume B = 7.5 L
Yields 1 result and you pay for one sample
– Result weighted sample (pay for 2 analysis)
Sampling Schedule
• Laboratory schedule will dictate your
sampling schedule
– The sooner you select a lab and start
sampling, the better date selection you will
have
– Sampling schedule must be consistent from
month to month. (Ex - 17th of each month)
• Sample must be collected within 2 days of date
selected (Ex – 15th to 19th)
Shipping
• Overnight
– Will shipper accept coolers?
– Do they charge extra for handling coolers?
• Do not allow contents to freeze
– Insulation between blue
ice and filters or bulk sample
– Max temp < 20 C
• Do not forget the
paperwork
– Datasheets
– Chain of custody record
Results
• Turnaround time
– 10 to 15 days but check with lab
• Shorter TAT can lead to higher costs
Sampling Equipment Selection
• 15 Liter Poly Carboy (2)
• ½” – 5/8” dia. reinforced
•
vinyl hoses
Garden hose type quick
disconnects
Sampling Equipment Selection
• SHURflo diaphragm
pump
– 1.7 gpm
– 95 psi max
• Filta-Max filter holder
or
• Envirochek filter
Sampling Equipment Selection
• Badger flow meter
– Gallons
– Totalizer
• Flow control valve
Raw Water Sampling Sites
• 2 separate sources
– Surface water
• Chemical added and treated
prior to mixing with
groundwater
– Groundwater
Groundwater
Actiflo
Big Sioux
River
Potassium
Permanganate
Backwash Water
Sampler Setup
Data
Collection
Sheet
Finished
Water
Sampling
Results
(To be Grandfathered)
• 50 samples since Jan 20, 2004
– Average volume collected – 10.5 L
– No detections (Detect limit Avg 9.78 / 100 L)
– E. Coli range < 1 to 200 colonies / 100 ml
– Turbidity range 2.4 - 24 NTU
• 3 Matrix spike samples
– Crypto recovery range 38.4 – 58 %
– Giardia recovery range 43.4 – 68.7 %
Summary of all Results
• Big Sioux River (1994 to present)
– Only sample when on-line
• Cryptosporidium
– 2 detections
– Range from 17.2 – 100 cysts per 100 L
– Last detection Jan 2004
• Giardia
– 6 detections
– Range from 4.9 – 83 cysts / 100 L
– Last detection Dec 2002
Summary of All Results
• Raw Water (1994 – Present)
– Cryptosporidium
• 4 detections
• Range from 1 – 89 cysts per 100 L
• Last detection May, 1996
– Giardia
• 9 detections
• Range from 9 – 333 cysts / 100 L
• Last detection Oct 2000
• Finished Water (1994 – Present)
– No detections
– Average detection limit of 1.2 / 100 Liters

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