Appendix G
Envirochek™ Field Filtration for Cryptosporidium
Procedure for Field-Filtering Samples for Cryptosporidium Analysis Using the Pall Life Sciences Envirochek™ or Envirochek™ HV Capsules
1.0 Materials
The following materials should be available before collecting sample:
- Several pairs of new, powder-free latex gloves
- Sample collection form (Appendix F)
- Pall Life Sciences Envirochek™ or Envirochek™ HV capsule (recommend that two capsules be kept on hand in case the first one clogs prior to filtering 10 L)
- Sanitary $30 L carboy (if sample is not from a pressurized source)
- Stopwatch
- Sample label
- Cooler, approximately 16-quart
- Temperature monitoring device (e.g., thermometer vial, Thermochron™ iButton, or equivalent) (if measuring temperature during shipment)
- Two large plastic trash bags
- One 8-lb bag of ice or gel ice packs
- Three gallon size ziplock bags
- Strapping tape
- Two self-adhesive plastic airbill sleeves
- Airbill for shipment
- The following items may be purchased as a unit for sampling from a vendor or laboratory supplying sampling apparatus for field filtering Cryptosporidium samples:
- Pump (if sample is not from a pressurized source) – Electric centrifugal or Electric peristaltic pump, or any equivalent pump that can create a flow of approximately 2 L/min
- Two 0.5-in. X 0.375-in. barbed reducing connectors
- Five lengths of clean 12.7-mm (0.5-in.) internal-diameter clear, vinyl, laboratory tubing
- Five pairs of hose clamps fit to tubing
- One 0.5-in. x 3-in. nipple
- One coupling to fit 0.5-in. internal diameter tubing
- One roll teflon tape
- One 0.5-in. x 0.5-in. x 0.25-in. tee Q Six 0.5-in. barbed male adapters One garden hose barbed adapter Pressure regulator
| Q | Pressure gauge (capsule’s maximum operating pressure, Envirochek™ – 30 PSID, Envirochek™ |
| HV – 60 PSID) | |
| Q | Water meter (flow totalizer) |
| Q | Flow rate meter with valve or flow control valve (capsule’s maximum flow rate, Envirochek™ |
| 2 L/min, Envirochek™ HV – 4 L/min) | |
| 2.0 | Collecting the Sample |
If the sample will be collected from a pressurized source, use the sample collection procedures in Section
2.1. If the sample will be collected from an unpressurized source, use the sample collection procedures in Section 2.2.
2.1 Sample Filtration from a Pressurized Source
- Before connecting the sampling system to the tap or source, turn on the tap and allow the water to flow for 2 to 3 minutes until the temperature has stabilized or until any debris that has accumulated in the source water lines has cleared and the turbidity in the water becomes visibly uniform. Turn off the
- Put on a pair of powder-free latex gloves to prevent contamination from outside sources. Any contamination inside the sampling apparatus may bias the final
- Determine the pressure of the water source with the pressure
- Assemble the sampling system, minus the Envirochek™ /Envirochek™ HV capsule. In place of the Envirochek™ /Envirochek™ HV capsule, insert a 0.5-in. barbed connector between the outlet tubing from the sample valve or the pressure regulator or gauge and the inlet tubing of the flow totalizer, flow meter or control valve. For high pressure (>30 PSIG for Envirochek™ capsule or
>60 PSIG for Envirochek™ HV capsule) sites, the sampling system should be assembled in the following order, as shown in Figure 1 below:
- Reinforced influent tubing
- Pressure regulator
- Pressure gauge
- Reinforced inlet tubing
- Envirochek™ /Envirochek™ HV capsule
- Reinforced outlet tubing
- Flow totalizer (mechanical or graduated collection device)
- Flow rate meter with valve or flow control valve
- Effluent tubing to drain
Figure 1.Sample System Setup for Collecting Cryptosporidium Samples from a Pressurized Source ( >30 PSIG for Envirochek™ capsule or >60 PSIG for Envirochek™ HV capsule)
For low pressure (1 to 30 PSIG for Envirochek™ capsule or 1 to 60 PSIG for Envirochek™ HV capsule) sites, the sampling system should be assembled at the sample port valve in the following order, as shown in Figure 2 below :
- Influent tubing
- Envirochek™ /Envirochek™ HV capsule
- Outlet tubing
- Flow rate meter with valve or flow control valve
- Flow totalizer (mechanical or graduated collection device)
- Effluent tubing to drain
Figure 2.Sample System Setup for Collecting Cryptosporidium Samples from a Pressurized Source (1 – 30 PSIG for Envirochek™ capsule or 1 – 60 PSIG for Envirochek™ HV capsule)
- Connect the sampling system, with the connector in place of the Envirochek™ /Envirochek™ HV capsule, to the pressurized water system, using appropriate fittings and
- Slowly turn the tap to fully open. Allow a minimum of 20 L to flush the system. During this period, perform the following steps:
- Measuring the flow rate with the flow rate meter or the flow totalizer and a stopwatch, adjust the flow rate to approximately 2 L/min (approximately 0.5 gpm) for the Envirochek™ capsule or 4 L/min (approximately 1.0 gpm) for the Envirochek™ HV capsule. If a flow control valve at the appropriate flow rate is used, no adjustment of the flow rate is necessary. Using the pressure regulator, adjust the pressure to a maximum of 30 PSIG if using the Envirochek™ or 60 PSIG if using the Envirochek™ HV. Observe the system for leaks and take the necessary corrective action if any are
- Record the following information on the sample collection form (Appendix F):
- Public water system (PWS) name
- PWS address
- Sampler name
- Sample ID (optional)
- Public Water System Identification (PWS ID) number
- Public Water System facility ID number
- Facility name
- Sample collection point ID O Sample collection point name Sample collection date
- Source water type (optional [but required for E. coli sample forms])
- Requested analysis (circle Cryptosporidium field sample for routine monitoring sample; circle both “Cryptosporidium field sample” and “Cryptosporidium matrix spike” sample if you are sending an additional sample with the monitoring sample for matrix spike analysis)
- After the assembly has been flushed, measure the turbidity of the source water and any optional water quality parameters such as temperature, and/or
- Turn off the water at the sample port valve when the flow rate has been adjusted and the system has been
- Record the following information on the capsule label with a waterproof pen:
PWS ID
Facility name
Date of sample collection
- Record the following information on the sample collection form:
Initial meter reading
- Remove the connector and in its place, install the Envirochek™ /Envirochek™ HV capsule in line, securing the inlet and outlet ends with the appropriate fittings/clamps.
Note! Retain the vinyl caps provided with the Envirochek™ /Envirochek™ HV capsule. These caps will be needed to seal the capsule for shipment.
- Slowly turn on the pressurized water source. Adjust the flow rate to approximately 2 L/min for Envirochek™ capsule or 4 L/min for Envirochek™ HV capsule, if necessary. Record the following information on the capsule label or sample collection form:
Start time
- Vent the residual air in the capsule using the bleed valve by turning it counter-clockwise. When the capsule is full of water, close the bleed
- Monitor the water meter. When the targeted volume (actual sample volumes will be selected by the utility, but volumes are typically 10 L [2.64 gal] to 50 L [13.2 gal] and preferred to be consistent between sampling events for each source) has passed through the Envirochek™
/Envirochek™ HV capsule, shut off the water source. Allow the pressure to decrease until the water stops.
- Record the following information on the capsule label and/or sample collection form:
Stop time (when the water was shut off)
Final meter reading
Comments to laboratory, if needed
- With the capsule inlet pointed up, loosen the outlet end of the Envirochek™ /Envirochek™ HV capsule and allow water to drain as much as possible. Water drainage from the capsule through the outlet is acceptable, as the sample has passed through the membrane. Opening the bleed valve during the draining will speed the process. Be sure to close the valve when
- Disconnect the inlet end of the Envirochek™ /Envirochek™ HV capsule, making sure not to spill any of the water remaining in the capsule through the inlet port. This water is part of your sample. Capsule may be shipped with or without residual
- Seal the inlet of the capsule with the vinyl end cap that was previously
- Seal the outlet of the capsule with the vinyl end cap that was previously saved. Place the Envirochek™ /Envirochek™ HV capsule in a plastic ziplock bag for
- Immediately following sample collection, place the bag containing the capsule in a refrigerator to chill prior to packing the shipping cooler for shipment. If no refrigerator is available, and the sample will not be shipped for several hours, place the bag in the shipping cooler with ice to chill. Replace the ice with fresh ice before
Note! Method 1622/1623 requires that the temperature of the sample upon arrival at the laboratory must be #20°C (but not frozen), and the laboratory must begin sample processing within 96 hours of sample collection. If the sample temperature and holding time requirements are not met, then the sample is invalid and must be recollected.
2.2 Sample Filtration Using an Unpressurized Source
- Put on a pair of powder-free latex gloves to prevent contamination from outside sources. Any contamination inside the sampling apparatus may bias the final
- If sampling from a source of unlimited volume, it may be desirable to pre-flush the sampling system. Assemble the sampling system, minus the Envirochek™ /Envirochek™ HV capsule. In place of the Envirochek™ /Envirochek™ HV capsule, insert a 0.5-in. coupling to connect the influent tubing to the inlet tubing of the pump. The sampling system should be assembled in the following order, as shown in Figure 3 below:
Influent tubing
Envirochek™ /Envirochek™ HV capsule
Outlet tubing
Centrifugal or peristaltic pump
Tubing
Flow rate meter with valve or flow control valve
Flow totalizer (mechanical or graduated collection device)
Effluent tubing to drain
Figure 3. Sample System Setup for Collecting Cryptosporidium Samples from an Unpressurized Source
When assembling sample chain, make sure that it is as airtight as possible in order to create a vacuum. To accomplish this, make sure that clamps are used at each connection and that rubber washers are inserted into the hose connections on the inlet and outlet ends of the centrifugal pump.
- Place the inlet end of the inlet tubing into the sample source, away from any walls, bottom, or other environmental
- Turn on the pump and allow a minimum of 20 L to flush the system. If sampling source water from a carboy, continuously refill the carboy as necessary to flush the system. As a recommendation, the carboy should not be removed from the sampling chain and should be refilled using a separate container. Observe the system for leaks and take the necessary corrective action if any are present. During this period, perform the following steps:
- Measuring flow rate with the flow rate meter or the flow totalizer and a stopwatch, adjust the flow rate to approximately 2 L/min (approximately 0.5 gpm) for the Envirochek™ capsule or 4 L/min (approximately 1.0 gpm) for the Envirochek™ HV capsule by varying the pump speed or adjusting the valve (if pump is not variable speed). If a flow control valve at the appropriate flow rate is used, no adjustment of the flow rate is
- Record the following information on the sample collection form:
- Public water system (PWS) name
- PWS address
- Sampler name
- Sample ID (optional)
- Public Water System Identification (PWS ID) number
- Public Water System facility ID number
- Facility name
- Sample collection point ID O Sample collection point name O Sample collection date
- Source water type (optional [but required for E. coli sample forms])
- Requested analysis (circle Cryptosporidium field sample for routine monitoring sample; circle both “Cryptosporidium field sample” and “Cryptosporidium matrix spike” sample if you are sending an additional sample with the monitoring sample for matrix spike analysis)
- Turn off the pump when the flow rate has been adjusted and the assembly has been
- Record the following information on the capsule label:
PWS ID
Facility name
Date of sample collection
- Record the following information on the sample collection form:
Initial meter reading
- Install the Envirochek™ /Envirochek™ HV capsule in line, securing the inlet and outlet ends with the appropriate fittings/clamps.
Note! Retain the vinyl caps provided with the Envirochek™ /Envirochek™ HV capsule. These caps will be needed to seal the capsule for shipment.
- Refill the carboy with the sample to be filtered. As a recommendation, the carboy should not be removed from the sampling assembly and should be refilled using a separate
- Turn on the pump. Adjust the flow rate to approximately 2 L/min for the Envirochek™ capsule or 4 L/min for the Envirochek™ HV capsule, if necessary. Record the following information on the capsule label and/or sample collection form:
Start time
- Monitor the water meter continuously refilling the carboy as needed. When the targeted volume (actual sample volumes are selected by the utility, but volumes are typically 10 L [2.64 gal] to 50 L [13.2 gal] and preferred to be consistent between sampling events for each source) is reached, remove tubing from the carboy and then shut off the
- Record the following information on the capsule label and/or sample collection form:
Stop time (when the pump was shut off)
Final meter reading
Comments to laboratory, if needed
- With the capsule inlet pointed up, loosen the outlet end of the Envirochek™ /Envirochek™ HV capsule and allow water to drain as much as possible. Water drainage from the capsule through the outlet is acceptable, as the sample has passed through the membrane. Opening the bleed valve during the draining will speed the process. Be sure to close the valve when
- Disconnect the inlet end of the Envirochek™ /Envirochek™ HV capsule, making sure not to spill any of the water remaining in the capsule through the inlet port. This water is part of your sample. Capsule may be shipped with or without residual
- Seal the inlet of the capsule with the vinyl end cap that was saved
- Seal the outlet of the capsule with the vinyl end cap that was saved previously. Place the Envirochek™ /Envirochek™ HV capsule in a plastic ziplock bag for
- Immediately following sample collection, place the bag containing the capsule in a refrigerator to chill prior to packing the shipping cooler for shipment. If no refrigerator is available, and the sample will not be shipped for several hours, place the bag in the shipping cooler with ice to chill. Replace the ice before
Note! Method 1622/1623 requires that the temperature of the sample upon arrival at the laboratory must be #20°C (but not frozen), and the laboratory must begin sample processing within 96 hours of sample collection. If the sample temperature and holding time requirements are not met, then the sample is invalid and must be recollected.
3.0 Packing the Sample
- Insert two large plastic trash bags into the shipping cooler to create a double liner. Immediately before packing the cooler, create two 4-pound bags of ice in two separate ziplock bags. To prevent leaks place each ice pack into an additional ziplock bag. Gel packs or blue ice may be used instead of wet ice, as long as the sample is maintained in the appropriate temperature Seal the ziplock bags, expelling as much air as possible, and secure top with tape.
Note! Shipping companies may delay sample shipments if leakage occurs. Double liners and ziplock bags around ice will prevent leakage and delays.
- Place the bag containing the capsule into the shipping container. Wrap the capsule in bubble wrap to prevent freezing. Inflated, empty sample bags can be placed between the capsule and the ice packs to prevent the sample from
- If you will be monitoring sample temperature during shipment, place in the cooler the temperature monitoring device (e.g., extra sample bottle for measuring sample temperature upon receipt at the laboratory, thermometer vial, or Thermochron™ iButton). Seal each liner bag by twisting top of bag and tying in a
- Peel the backing off one of the plastic airbill sleeves and attach the sleeve to the inside of the cooler
Sign and date the sample collection form.
Fold the completed sample collection form, and place it inside the plastic sleeve.
- Close the cooler lid, seal the horizontal joints with strapping tape, and secure the lid with tape by taping the cooler at each end, perpendicular to the
Note! Shipping companies may delay sample shipments if leakage occurs. Be sure to seal the cooler joints.
- Peel the backing off of the second airbill sleeve and attach the sleeve to the outside of the cooler lid. Complete the shipping airbill with the laboratory address, billing information, sample weight, and shipping service. Remove the shipper’s copy of the airbill, and place the remainder of the airbill inside the plastic
4.0 Shipping and Tracking
- Ship samples on the day of collection and use a reliable shipping service for overnight delivery. If samples are not shipped the day of collection, the sample must be maintained between 1°C and 10°C (but not frozen) by chilling in a refrigerator or cooler filled with
- Contact the laboratory to notify them of the sample shipment. Request that the laboratory contact you the next day if the sample is not
- Using the airbill number on the shipper’s copy of the airbill, track the sample shipment using the shipping company’s web page or by contacting the shipping company over the
- If problems are encountered with the shipment, communicate with the shipping company to resolve, and update the laboratory regarding the status of the