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Electronic copies of all the information in this package are located at www.tceq.state.tx.us/goto/pws/lt2
Sample Schematics:
Choose the ONE of the sample schematics that most resembles the arrangement for your raw water source and treatment plant(s). Mark it with a pen as needed. Indicate where the samples will be taken. If you recycle your filter backwash water, indicate on the schematic where the recycled filter backwash water re-enters the treatment process.
All samples must be taken at a point prior to any chemical treatment and prior to any re-entry of recycled filter backwash water.
If there is another schematic on the opposite side of the schematic that you have chosen, please cross it out with your pen (to prevent bleeding through, please do not use a marker). You can create your own schematics if you choose.
Figure 1. Sample Tap before Chemical Treatment and Backwash Water Recycle (if applicable)
Raw water
Source water
LT2
LT2 sample point
Chemical
Backwash water recycle
LT2 Rule:
chemical building
Raw water intake
Backwash water recycle (if applicable)
Water treatment plant
sample point
addition
(if applicable)
Systems must collect source water samples prior to chemical treatment [40 CFR § 141.703(b)(1)], unless approved by the State to
collect source water samples after chemical treatment [40 CFR § 141.703(b)(2)]. Systems that recycle filter backwash water must collect source water samples prior to the point of filter backwash
water addition [40 CFR § 141.703(c)].
Backwash water lagoon
Figure 2. Multiple Sources: Sample Tap after Two Combined Sources
§
Multiple Alternating Sources: l
LT2 Rule:
Source water “B”
Raw water blending station
Raw water intake
Backwash water recycle (if applicable)
Water treatment plant LT2 sample point
Source water “A”
If a sample tap is available where the sources are combined prior to treatment, the sample must be
collected from the tap [40 CFR 141.703(e)(1)] *
* Systems unable to sample from this combined source location
should refer to Figure 3.
Chemical addition
Systems that use multiple a ternating sources (seasonal or due to water quality changes) must
sample from the source water in use on the designated sampling date following normal operating practices
[40 CFR § 141.703(e)].
Systems must collect source water samples prior to chemical treatment [40 CFR § 141.703(b)(1)], unless approved by the State to
collect source water samples after chemical treatment [40 CFR § 141.703(b)(2)]. Systems that recycle filter backwash water must collect source water samples prior to the point of filter backwash
water addition [40 CFR § 141.703(c)].
Backwash water lagoon
Figure 3. Multiple Sources: Two (or More) Sources to be Composited
)
addition
75% of flow
25%
of flow
l
l l
Source water “B”
Raw water blending station
Raw water intake
Backwash water recycle (if applicable
Water treatment plant
Source water “A”
Chemical
Manually collect sample
Manually collect sample
If a sampling tap where the sources are combined prior to treatment is not available, systems must
collect samples at each source near the intake on the same day and follow the options discussed
below [40 CFR § 141.703(e)(2)].
LT2 Rule: Systems must col ect source water samples prior to chemical treatment [40 CFR § 141.703(b)(1)], unless approved by the State to collect source water samples after chemical treatment [40 CFR § 141.703(b)(2)].
Systems that recycle filter backwash water must col ect source water samp es prior to the point of filter backwash water addition [40 CFR § 141.703(c)].
Backwash water lagoon
)(2)(i)].
Source water “A”
Source water “B”
100%
l
l pl
water
water
Analyzed
Analyzed
OPTION 1 (Recommended Option): Collect samples manually at each source near the intake on the same day and composite them into one sample to be analyzed. The volume of sample from each source must reflect its proportion of the total plant flow at the time the samples were collected [40 CFR § 141.703(e
75% 25%
To be analyzed
Collect samples manually at each source near the intake on the same day and analyze each independently, then calcu ate a weighted average of the analysis results. This is done by multiplying the result for each source by the percentage of its contribution to the tota ant flow at the time the samples were collected, and then summing these values [40 CFR § 141.703(e)(2)(ii)].
Source
“A”
Source
“B”
Multiply result by percentage of
contribution to total flow
Multiply result by percentage of
contribution to total flow
Sum together all source water
results for total value
OPTION 2:
Figure 4. Multiple Plants with the Same Influent
LT2 sample point
Chemical addition
To plant “A”
)].
ll
E-5
Source water
Raw water chemical building
Raw water intake Water treatment plant “A”
LT2 sample point
Water treatment plant “B”
To plant “B”
Where multiple plants draw from the same influent, such as the same pipe or intake, the State may
approve one set of monitoring results to be used to satisfy the requirements for all plants [40 CFR §
141.703(a
LT2 Rule: Systems must collect source water samples prior to chemica treatment [40 CFR § 141.703(b)(1)], unless approved by the State to col ect source water
samples after chemical treatment [40 CFR § 141.703(b)(2)]. Systems that recycle filter backwash water must collect source water samples prior to the point of filter
backwash water addition [40 CFR § 141.703(c)].
Figure 5. Bank FiltrationThe correct sampling location for systems using bank filtration differs depending
on whether the bank filtered water is treated by subsequent filtration:
stream
addition
and
Raw water chemical building
Backwash water recycle (if applicable)
Water treatment plant
Flowing
Lateral well
Well Chemical
Sand
gravel
Scenario 1: Systems that receive Cryptosporidium treatment credit for bank filtration must collect
source water samples in the surface water prior to bank filtration [40 CFR § 141.703(d)(1)].*
Groundwater
Minimal surface water mixing with
ground water
Manually collect sample
Backwash water lagoon
Bank filtration cross section
i
Cryptosporidium
(
i
Well point
Scenario 2: Systems using bank filtered water that is treated by subsequent filtrat on must collect source water samples from the well source (i.e., after bank
filtration) but before any other treatment.** Use of bank filtration during monitoring should be consistent with routine operational practice. Systems
collecting samples after a bank filtration process may not receive treatment credit for the bank filtration [40 CFR § 141.703(d)(2)].
* Refers to systems using bank filtration to meet Cryptosporidium removal requirements of the Interim Enhanced Surface Water Treatment Rule IESWTR) or Long Term 1 ESWTR under 40 CFR § 141.173(b) or 40 CFR § 141.522(a). ** Refers to systems where bank filtrat on serves as pretreatment to a filtration plant.
Raw water chemical building
Backwash water recycle (if applicable)
Water treatment plant
Bank filtration cross section
Flowing stream
Lateral well
Chemical addition
Sand and
gravel
Groundwater
Minimal surface water mixing with
ground water
LT2 sample
Backwash water lagoon
Figure 6. Ground Water Under the Direct Influence of Surface Water (GWUDI)
Well
LT2
point
Cryptosporidium igure 5).
LT2 Rule:
Raw water chemical building
Backwash water recycle (if applicable)
Water treatment plant
Flowing stream
Chemical addition
Groundwater
Water table Water table
sample
Systems that use ground water under the direct influence of surface water (GWUDI) must collect source water samples from
the well source unless they received treatment credit for bank
filtration (see F
Systems must collect source water samples prior to chemical treatment [40 CFR § 141.703(b)(1)], unless approved by the State to
collect source water samples after chemical treatment [40 CFR § 141.703(b)(2)]. Systems that recycle filter backwash water must collect source water samples prior to the point of filter backwash
water addition [40 CFR § 141.703(c)].
GWUDI cross section Backwash water lagoon
Figure 7. Presedimentation Basin
Scenario 1: Systems using a presedimentation basin with chemical addition should collect source water samples prior to chemical treatment, unless approved by the State to collect source water
samples after chemical treatment. Systems that recycle filter backwash water must collect source water samples prior to the point of filter backwash water addition [40 CFR § 141.703(c)].
LT2
additionSource water
Raw water chemical building
Raw water intake
Backwash water recycle (if applicable)
Water treatment plant
sample point
Presed. basin
Chemical
Backwash water lagoon
Scenario 2: Systems without chemical addition prior to or in a presedimentation basin, or that have been approved by the State to collect source water samples after chemical treatment, may sample
after the presedimentation basin but will not receive any treatment credit for presedimentation.
LT2
point
no
Source water
Raw water intake
Water treatment plant Presed. basin
sample
Sampling here will result in Cryptosporidium
treatment credit
Figure 8. Raw Water Off-Stream Storage
storage
LT2
addition
LT2 Rule:
Sour
ce w
ater
Raw water off-stream
Raw water chemical building
Raw water intake
Backwash water recycle (if applicable)
Water treatment plant
sample point Chemical
Source water samples should be collected after the off-stream storage reservoir. Use of off-stream storage
during monitoring should be consistent with routine operational practice.
Systems must collect source water samples prior to chemical treatment [40 CFR § 141.703(b)(1)], unless approved by the State to
collect source water samples after chemical treatment [40 CFR § 141.703(b)(2)]. Systems that recycle filter backwash water must collect source water samples prior to the point of filter backwash
water addition [40 CFR § 141.703(c)].
Backwash water lagoon
Figure 9. Mixed Source Water: Ground Water and Surface Water Sources
Ground water well cross section
addition
addition
Well
Groundwater
To
i
prior to treatment, systems must
)
Scenario 2:
ll
Source water
Water treatment plant Raw water
chemical building
LT2 sample point Chemical
Raw water intake
Ground water well cross section
Well
Groundwater
Water table
Scenario 1:
Water treatment plant Raw water
chemical building
LT2 sample point Chemical
Source water
Water table
distribution system
If a sample tap is ava lable where the sources are combined
collect samples from the tap [40 CFR § 141.703(e)(1)]. Systems
unable to sample from this combined source location should
refer to Figure 3.
Backwash water recycle (if applicable)
Backwash water recycle (if applicable
Systems that use ground water pumped directly to the distribution system should
collect samples only from the surface water source and prior to backwash water
or chemical addition.
Raw water intake
Ground water sources are not required to be monitored under the LT2 Rule.
No sample is needed from this source.
LT2 Rule: Systems must co ect source water samples prior to chemical
treatment [40 CFR § 141.703(b)(1)], unless approved by the State to collect source water samples after chemical treatment [40 CFR § 141.703(b)(2)]. Systems that recycle filter backwash
water must collect source water samples prior to the point of filter backwash water
addition [40 CFR § 141.703(c)].
Backwash water lagoon
Backwash water lagoon
Figure 10. Blank Schematic
Public Water System (PWS) name: ______________________________
PWS ID: ______________________________
Water treatment plant name: ______________________________
Water system facility ID: ______________________________
Indicate the following on the diagram that best represents your facility type (if applicable):
1. LT2 sampling location 2. Points of chemical treatment prior to the treatment plant 3. Filter backwash water addition 4. Pretreatment processes (e.g., presedimentation basins, bank filtration) 5. Multiple source waters (show by adding additional sources)
Source water
Water treatment plant