United States Office of Water EPA 815-R-99-019
Environmental Protection Agency 4606 February 2001
oEPA How to Determine
Compliance with
Optimal Water Quality
Parameters as Revised
by the Lead and Copper
Rule Minor Revisions
Printed on Recycled Paper
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TABLE OF CONTENTS
What Is The Purpose Of This Guidance Document? 1
How Is This Document Organized? 2
What Special Terms Does A System or State Need to Know to Understand this Guidance
Document? 3
How Has the Procedure for Determining Compliance Changed? 4
How Do the Monitoring Requirements Change When a System Is Out of Compliance? 10
How Do the Revisions Affect Systems that Are Not Required to Collect WQPs? 11
Have the Reporting Requirements Changed? 11
What Key Points Should Systems and States Remember? 12
APPENDIX A
Examples of How to Determine Compliance with OWQPs A-l
EXAMPLE 1: How To Determine Compliance
At Different Monitoring Locations And For Different WQPs A-2
EXAMPLE 2: How To Determine Compliance When Additional Samples Are Not Collected
In A Monitoring Period Following An Excursion A-7
EXAMPLE 3: How To Calculate Daily Values When
A System Monitors More Frequently Than Daily At A Sampling Location A-9
EXAMPLE 4: How To Determine Compliance When A System
Monitors Annually At A Sampling Location A-13
EXAMPLE 5: How To Determine Compliance When
A System Monitors Triennially At A Sampling Location A-l5
EXAMPLE 6: How To Determine Compliance For
A System That Operates Seasonally A-19
EXAMPLE 7: How To Determine Compliance For
A Small or Medium System with Intermittent Exceedances A-21
APPENDIX B
Lead and Copper Rule Minor Revisions that Relate to OWQP Compliance and Reporting
Requirements B-l
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Disclaimer
The statements in this document are intended solely as guidance. This
document is not intended, nor can it be relied upon, to create any rights
enforceable by any party in litigation with the United States. EPA may
decide to follow the guidance provided in this document, or to act at
variance with the guidance based on its analysis of the specific facts
presented. This guidance may be revised without public notice to reflect
changes in EPA's approach to implementing the authorities discussed in the
Guidance or to clarify and update text.
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How to Determine Compliance with
Optimal Water Quality Parameters
as Revised by the Lead and Copper Rule Minor Revisions
What Is The Purpose Of This Guidance Document?
On June 7, 1991, the Environmental Protection Agency or EPA published in the Federal Register, a
regulation to control lead and copper in drinking water. This regulation is known as the Lead and
Copper Rule. EPA also refers to this rule as the LCR or 1991 Rule. On January 12, 2000, EPA
published minor revisions to the 1991 Rule. The purpose of the Lead and Copper Rule Minor
Revisions (LCRMR) is to eliminate unnecessary requirements, streamline and reduce reporting
burden, and promote consistent national implementation. This document focuses on those changes
that may affect the way in which water systems and State Primacy Agencies will determine
compliance with the optimal water quality parameter (OWQP) ranges or minimums. State have the
option of continuing to use the approach outlined under the 1991 Rule, but EPA strongly encourages
States to incorporate this new compliance procedure into their drinking water regulations. Systems
should first check with their States before using this new compliance approach.
The LCRMR do not change the frequency with which water quality parameter (WQP) samples must
be collected or which systems are required to conduct WQP monitoring. Unless required by the
State, small systems (serving 3,300 or fewer people) and medium-size systems (serving 3,301 to
50,000 people) which do not exceed the lead or copper action level, are not required to conduct WQP
monitoring. The LCRMR clarify that large systems (serving more than 50,000 people) that meet the
criteria of §141.81(b)(3), by demonstrating that they have very low levels of lead and copper in the
distribution system, are not required to conduct WQP monitoring. The LCRMR also clarify that
systems that have completed treatment steps that are equivalent to those described in the 1991 LCR
prior to December 7, 1992 (i,e., meet the criteria of §141.81(b)(2)) must continue conducting WQP
monitoring after the State sets OWQPs.
OWQPs are set by the State after a system has collected WQP samples during two consecutive, 6-
month monitoring periods, following the installation of corrosion control treatment. OWQPs are
measured to determine whether a system is operating its corrosion control treatment at a level that
most effectively minimizes the lead and copper concentrations at users' taps.
EPA revised the procedure for calculating compliance with OWQPs from that in the 1991 Rule based
on concerns raised by several States and water systems. A major concern was that the 1991
compliance approach created a significant disincentive for sampling WQPs more frequently than
required, since the more frequently measurements are taken, the greater the potential that some of the
results will be outside the OWQP ranges or below the OWQP minimums set by the State. Under the
1991 Rule, a water system was out of compliance if the results of any WQP sample, or the average of
the original sample and a confirmation sample, did not meet the State-designated OWQP ranges or
values. Another concern was the "averaging" of results was not the best approach from an effective
corrosion control perspective. A system might have to increase pH scale and cause other problems
simply to set the average within range.
Compliance with OWQPs as Revised by LCRMR 1 February 2001
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How Is This Document Organized?
This guidance document is structured to answer the following questions:
• • What Special Terms Does A System or State Need to Know to Understand this Guidance
Document?
• • How Has the Procedure for Determining Compliance Changed?
• • How Do the Monitoring Requirements Change When a System Is Out of Compliance?
• • How Do the Revisions Affect Systems that Are Not Required to Collect WQPs?
• • Have the Reporting Requirements Changed?
• • What Key Points Should Systems and States Remember?
This document includes citations in brackets at the end of some of the sentences (e.g., [see
§141.86(g)] ). Wherever this document mentions a requirement that the system or the State must
follow, EPA has included, in brackets, the citation from the federal regulations that contains the
requirement. EPA also has included two appendices to this document. Appendix A contains seven
examples that illustrate how to assess OWQP compliance under various monitoring scenarios. The
monitoring frequencies in these examples range from multiple WQP samples collected per day, to
triennial WQP monitoring. In addition, one example focuses on how to determine compliance for a
system that operates seasonally. Another illustrates how to determine compliance for a small or
medium-size system that is required to collect WQPs periodically due to intermittent exceedances of
the lead or copper action level.
Appendix B contains federal regulatory language from the LCRMRthat specifies:
• • Continuing requirements for systems that have installed corrosion control treatment.
• • Monitoring requirements for systems that meet the criteria of § 141.81 (b)(2).
• • The revised procedure for determining compliance with OWQPs.
• • The monitoring requirements for systems that no longer meet their OWQPs.
• • Monitoring requirements after the State sets OWQPs.
• • When systems must report WQP results to the State.
• • Special State primacy conditions if a State elects to use a different formula for assessing
compliance when a system monitors more frequently than daily at a sampling location.
.-? Remember: The State's drinking water regulation may contain
/ slightly different wording, and may even be more stringent than the
federal regulations. In addition, the State's regulation may be
organized differently than those portions of the federal regulation
contained in Appendix B of this document. A system should
contact the appropriate State agency for a copy of its regulations.
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February 2001
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What Special Terms Does A System or State Need to Know to Understand this
Guidance Document?
Term
Definition
1991 Rule
90th
Percentile
Value
Action Level
Confirmation
Sample
Daily Value
Excursion
LCR
LCRMR
OWQPs
This refers to the Maximum Contaminant Level Goals and National Primary Drinking
Water Regulations for Lead and Copper, or Lead and Copper Rule for short. This
regulation was published in the Federal Register on June 7, 1991 (56 FR 26460). EPA
modified this rule with technical amendments that were published in the Federal
Register on July 15, 1991 (56 FR 32113), June 29, 1992 (57 FR 28786), and June 30,
1994 (59 FR 33860).
The highest concentration of lead or copper in tap water that is exceeded by 10 percent
of the sites sampled during a monitoring period. This value is compared to the lead or
copper action level, to determine whether an action level has been exceeded.
The concentration of lead or copper in tap water which determines whether a system
may be required to install corrosion control treatment, collect water quality parameter
samples, collect lead and copper source water samples, replace lead service lines,
and/or deliver public education about lead. The action level for lead is 0.015 mg/L.
The action level for copper is 1.3 mg/L.
Under the 1991 Rule, systems could collect a sample (known as a confirmation sample)
within 3 days for any WQP value that was not within its OWQP range or above its
minimum value. The result of this confirmation sample and the original value were
averaged together to determine compliance. This approach is no longer used under the
LCRMR.
This is a new term introduced under the LCRMR. "Daily values" are the sample
results of WQPs and are calculated for each WQP at each sampling location. They are
based on the sampling frequency for that WQP and sampling point.
This is also a new term under the LCRMR. It refers to a "daily value" for a WQP at a
sampling location that is below the minimum value or outside the range of values
designated by the State.
An acronym for the Lead and Copper Rule. Also referred to in this document as the
1991 Rule.
An acronym for the Lead and Copper Rule Minor Revisions that were published in the
Federal Register on January 12, 2000 (65 FR 1950).
An acronym for optimal water quality parameters. They are specific ranges or
minimums that are determined by the State for each relevant WQP. OWQPs represent
the conditions under which systems must operate their corrosion control treatment to
most effectively minimize the lead and copper concentrations at their users' taps.
Compliance with OWQPs as Revised by LCRMR
February 2001
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Term
Definition
State
WQPs
Refers to the government agency that enforces compliance with drinking water
regulations and assists systems in understanding and implementing these regulations.
For most systems, this is an organization within the State government (e.g., Department
of Natural Resources, Department of Environmental Quality, Department of Health).
For DC, WY, and Native American Lands, the contact is often from the respective EPA
Regional Office.
An acronym for water quality parameters. After corrosion control treatment is
installed, WQPs include: pH, alkalinity (when alkalinity is adjusted), orthophosphate
(when an inhibitor containing a phosphate compound is used), silica (when an inhibitor
containing a silicate compound is used), and calcium (when calcium carbonate
stabilization is used as part of corrosion control).
How Has the Procedure for Determining Compliance Changed?
Procedure under the 1991 Rule
Under the 1991 Rule, a system would be out of compliance if the results of any WQP sample were
below the minimum value or outside the range of values set by the State. Systems were allowed to
take a confirmation sample within 3 days of the original sample. If a system collected a confirmation
sample, the results of the original sample and the confirmation sample were averaged to determine
compliance. Since any sample (or the average of an original and a confirmation sample) falling
outside the range or below the minimum could result in a violation, systems that collected samples
more frequently than the minimum requirement had a greater potential for not meeting their OWQP
levels and to be in violation. From the standpoint of process control, monitoring OWQPs more
frequently than the minimum required by the regulations enables systems to detect problems and
make corrections sooner.
Another reason for changing the compliance procedure is that an averaging approach may allow a
system that is not using sound corrosion control treatment practices to remain in compliance. For
example, assume a State sets a WQP pH range of 7.3 to 7.8 for a system. Suppose a caustic feed
pump is used at the wellhead or at the end of a water plant feeding into the system, and the system is
not adequately controlling the pump. The system collects a sample with a pH of 6.9. Three days
later, they collect a second sample, and this one has a pH of 8.4 (also outside the OWQP range). The
average (7.6) is within the range, but the process control is poor. This is a common affliction of lime
feed treatment at many small and some medium-sized treatment plants. The goal of this monitoring
is good process control and the current approach has the potential to reward poor process control as
seen in this example.
The revised approach is also more consistent with the goals of corrosion control. Impacts on other
rules must be considered, when systems select a corrosion control strategy [see §141.82(c)(5)]. Thus,
the constraints imposed by other rules will also be factored into the OWQPs. The averaging
Compliance with OWQPs as Revised by LCRMR 4 February 2001
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procedure in the 1991 Rule can affect compliance with other rules. The example in the preceding
paragraph can be used to illustrate this problem. Suppose the pH upper limit of 7.8 was set because
of problems with compliance with total trihalomethanes (TTHMs) at higher pHs. Thus, to maintain
compliance with the LCR, the system could have problems meeting TTHMs. The Lead and Copper
Rule Guidance Manual Volume II: Corrosion Control Treatment, September 1992, lists constraints
that should be considered for the three types of corrosion control treatment. Many constraints may be
affected if systems need to exceed the range for optimal corrosion control to produce an average that
is within the OWQP range. The revised approach avoids this problem because the system is only
required to be within the range and the range already incorporates the constraints. Thus, the revised
approach is more protective of public health since other treatment processes can be adversely
impacted under the current approach in the LCR.
Procedure under the LCRMR
The LCRMR do not change system WQP monitoring requirements, only the way in which
compliance is determined.
Under the LCRMR:
1 Compliance determinations are always based on a 6-month period, regardless of the
system's monitoring schedule (e.g., daily, biweekly, semi-annually, annually, triennially) or
whether the WQP results are from an entry point or the distribution system [see §141.82(g)].
The start of the first 6-month period begins on the day the State has designated OWQPs,
however, to make tracking easier, the start of the first 6-month compliance period can be either
January 1st or July 1st.
2. Systems cannot be outside the OWQP ranges or below the OWQP minimum for more
than a total of 9 days at a specific sampling point or combination of sampling points, or for a
specific WQP or combination of WQPs during a 6-month period. The 9 days can occur
anytime during the 6-month period and do not have to be consecutive. Nine days was selected
because this number represents five percent of the total number of days in a 6-month period.
Thus, a system must meet its OWQP specifications at least 95 percent of the time. The 9 days
also allow systems to make necessary repairs that may be causing the system to not meet its
OWQP specifications [see §141.82(g)].
3. Confirmation samples are no longer used. The results of all WQP samples collected during
the 6-month period at a sampling location that is used for OWQP compliance must be reported
to the State by the system and used in determining compliance. However, States have
discretion to delete results of obvious sampling errors from this calculation [see §141.87(f)].
The LCRMR introduce two new terms with which States and systems need to become familiar to
fully understand the new compliance procedure. The first term is "daily value". Daily values are
calculated for each WQP at each sampling location. The procedure for determining the daily value is
based on the sampling frequency for that WQP and sampling point.
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It is quite possible for a system to collect several samples a day for a given WQP at one sampling
location and to conduct annual monitoring at another. Although the term "daily values" contains the
word "daily", in many instances, the daily value represents a measurement that was collected more or
less frequently than once per day. The table below explains how to calculate the daily value based on
the sampling frequency for a given WQP.
• 'Note: A daily value is calculated for each sampling location and for each
parameter, even if no monitoring occurred at a sampling location during
the 6-month period being evaluated. This occurs when a system is on an
annual or triennial WQP tap monitoring schedule (see example below).
Daily Value Calculation Based on Monitoring Frequency
If a system is monitoring
for a specific WQP at a
sampling site:
Then the daily value is:
More frequently than
Daily
Daily
Biweekly
Semi-annually
Annually or Triennially
Calculated by averaging all the results measured at the sampling location for
that WQP during the day. If both continuous monitoring results and grab
samples are collected on the same day, both must be included in the
calculation of the daily value. States can specify the frequency with which
continuous monitoring results should be recorded.
A State can also require systems to determine the "daily value" using another
formula when they monitor more frequently than daily at the same sampling
location. If a State elects to use a different calculation than that specified in
the federal rule, it must describe the procedure in its revised primacy package
[see §141.82(g)(l) and §142.16(d)(l)(ii)]. Systems should check with their
States regarding the frequency of recording values and procedures for
aggregating results.
Results of each daily sample for that WQP at that location.
Results of each sample collected during the 2-week period for that WQP at
that location.
Results of each sample collected during the 6-month period for that WQP at
that location.
The most recent measurement(s) taken, even if the measurement(s) was
(were) collected during a previous monitoring period.
Example: A system is on annual WQP tap monitoring during January -
December 2000. It measures pH at the tap on January 10, 2000 (pH = 7.5)
and June 20, 2000 (pH = 7.6). For the 6-month period of January to June
2000, there are two daily values because both measurements were collected
during the 6-month period being evaluated. For the 6-month period of July to
December 2000, only the most recent value of 7.6 is used.
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February 2001
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Remember: If a system collects additional WQP samples during the
monitoring period at a sampling point that is used to determine
compliance with OWQPs, the results are included in the compliance
assessment. However, States have discretion to delete results of
obvious sampling errors from this calculation [see §141.82(g)].
The second new term is an "excursion". An excursion is any "daily value" for a WQP that is below
the minimum value or outside the range of OWQPs set by the State. The duration of an excursion is
the number of days that elapse starting with the day the excursion first occurs, until the day the daily
value is within the OWQP range or above the OWQP minimum for that WQP. These dates are based
on the date the system collected the sample, not the date the system received the sample results.
To determine the duration of the excursion:
1. Count the first day that the sample is outside the OWQP range or below the minimum.
Use the date that the sample was collected and not the day the system or State received the
results.
2. Stop counting days when a sample result from the same location and for the same
parameter meets the OWQP range, or is at or above the minimum value. Do not count
the day the sample falls within the OWQP range, or is at or above the minimum value in the
calculation.
For example, assume a water system measures entry point pH on a Monday and the results are
below the State-set minimum. If the system again measures pH at the same entry point on the
next day and the Tuesday daily value is within the State-set limits, the system will have had a
one-day excursion. If, on the other hand, the system waits until Friday to measure pH as the
same entry point and this Friday measurement is within the State-set limits, the system will
have an excursion with a duration of 4 days (i.e., the system was outside the pH range for
Monday, Tuesday, Wednesday, and Thursday).
3. Repeat this procedure any time a measurement does not meet the OWQP specifications
during the 6-month period being evaluated.
To determine if a system is in compliance, count the total number of days that a system had an
excursion for each sampling location and for each WQP. Multiple excursions that occur on the same
day are only counted once. For example, if the system had an excursion for pH and alkalinity on the
same day, this counts as only one excursion. To remain in compliance, a system cannot have
excursions on more than 9 different days at a specific sampling point or combination of sampling
points, or for a specific WQP or combination of WQPs during a 6-month period [see §141.82(g)].
Compliance with OWQPs as Revised by LCRMR 7 February 2001
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The 9 days can occur anytime during the 6-month period and do not have to be consecutive. Thus, a
system that had excursions for pH at sampling point 1 for 4 days and excursions for pH at sampling
point 2 on 6 different days, would be out of compliance.
Other Points to Keep in Mind
Unresolved Excursions from a Previous Monitoring Period
Keep in mind that although compliance is determined in discrete 6-month periods, an unresolved
excursion from a previous monitoring period may count in the next 6-month monitoring period. This
is because an excursion continues until:
1. The system collects a sample at the same sampling location and for the same WQP that again
is within the OWQP range, or is at or above the OWQP minimum, or
2. The system is at or below both action levels and is no longer required to collect WQPs. Small
and medium-size systems (i.e., ones that serve 50,000 or fewer people) that no longer exceed
the lead or copper action level, and systems that meet the criteria under §141.81(b)(3) are not
required to collect WQP samples.
To illustrate these points, assume that a system is below the OWQP pH minimum of 7.0 at its one tap
sampling point on June 25, 2001. This excursion continues until the system again monitors pH at its
tap sampling point and the result is at or above the minimum of 7.0. Assume that the system does not
collect another pH sample that is above the pH minimum until July 3, 2001. How should this
excursion be counted?
During the January to June 2001 compliance period, the system had a 6-day excursion. The
excursion began on June 25th and continued to the end of the 6-month monitoring period of June 30th,
for a total of 6 days. During the July to December 2001 compliance period, the system had a 2-day
excursion. The excursion is counted from the beginning of the July to December compliance period
(i.e., July 1st) and ends when the system again is above the pH minimum at the tap sampling point (or
July 3rd in this example). The day that the system is above the minimum does not count. Therefore,
the system has an excursion on both July 1st and July 2nd.
Assume a slight variation on the above scenario. The system is below the OWQP pH minimum of
7.0 at its one tap sampling point on June 25, 2001. However, the system conducts lead and copper
tap monitoring on July 3rd and is below both action levels. The system serves 50,000 or fewer people
and is not required to conduct WQP monitoring during July through December 2001. How should
this excursion be counted?
For the compliance period of January to June 2001, the system has a 6-day excursion. For the
compliance period of July through December 2001, the system has 2 days with excursions. On July
3rd, the requirement to conduct WQP monitoring is no longer applicable (unless the State requires the
system to continue monitoring), and therefore, the system incurs no additional excursions. Note: The
LCRMR contain a provision that allows States to require continued WQP monitoring even after a
small or medium-size system is at or below both action levels should the State believe this monitoring
Compliance with OWQPs as Revised by LCRMR 8 February 2001
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is needed to insure adequate process control. Also note, that if the system did not collect its lead and
copper tap sample until July 10th or later, it would be out of compliance with its OWQPs because it
would have more than 9 days with excursions. If in the future, the system again exceeds the lead or
copper action level and is required to collect WQP monitoring, the unresolved excursion is not
considered. An unresolved excursion from a previous monitoring period is not considered for a small
or medium-size system if the 6-month period being evaluated was preceded by a 6-month OWQP
compliance period in which the system was not required to conduct WQP monitoring because the
system was at or below the lead and copper action levels. This is the only instance in which you do
not consider an unresolved excursion from a previous monitoring period. This point is also
illustrated in Example 7 in Appendix A.
Seasonal Systems
For NTNCWSs that are closed for a portion of the year, do not count the months that the system is
not open and providing water when counting the number of days with excursions. This point is
illustrated in detail in Example 6 in Appendix A.
Systems with Multiple Treatment Plants
If a system has multiple treatment plants with different OWQP specifications and the plants are not
interconnected, the plants should be treated as separate systems for the purpose of assessing
compliance with OWQPs. Assume that a system has two treatment plants. Excursions that exist at
Treatment Plant 1 would be considered separately from any excursions that occur at Treatment Plant
2. Thus, if the system had 4 days during a 6-month period with excursions at Treatment Plant 1 and 4
days with excursions at Treatment Plant 2 during the same 6-month period, the system would be in
compliance because it would not have exceeded the 9-day excursion limit.
When A Procedure Other Than Averaging May Be Appropriate
States have the option to designate a different formula than that outlined in §141.82(g)(l) for
aggregating multiple measurements collected during the same day for a WQP at a sampling location.
Section 141.82(g)(l) specifies that the daily value of a WQP is the average of all results collected
during the day at a given site, regardless of whether they are collected through continuous monitoring,
grab sampling, or a combination of both.
Some States may elect to use an alternative methodology for calculating daily values for OWQP
requirements. If so, the State must explain their alternative method and provide justification
sufficient to show it is at least as stringent as the average of the daily values described in
§141.82(g)(l).
In considering this option, States may have reason to believe an alternative formula may be more
representative for calculating daily values for WQPs for some systems. Examples of situations which
may trigger an alternative methodology include the following:
• For systems performing continuous monitoring of a WQP(s), the State may prescribe the
monitoring frequency at which data would be used for calculating the daily value. For
example, values recorded every four hours may be used to calculate the daily average.
Compliance with OWQPs as Revised by LCRMR 9 February 2001
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For systems with large fluctuations in the values obtained for a WQP(s) the extreme value
most detrimental to corrosion of distribution system piping may be required to be reported
(e.g., the lowest pH value obtained).
For sample locations at a common header which is served by multiple sources (and where
water quality fluctuates based on the particular sources in service at the time of sampling), a
formula representing the water quality contribution of the source providing the most water may
be required.
How Do the Monitoring Requirements Change When a System Is Out of
Compliance?
The LCRMR do not change what occurs if a system is out of compliance with any of its OWQPs.
However, the LCRMR contain language that helps clarify a system's monitoring requirements in the
event that it is out of compliance with its OWQPs. This language has been provided in Appendix B
[see §141.86(d)(4)(vi)(B) and §141.87(e)(4)].
If a system is out of compliance, it must:
1 . Report the violation to the State within 48 hours of determining the noncompliance [see
2. Deliver public notification to its customers. Refer to §141.201 & §§141.203 - 141. 206 or to
EPA' s Public Notification Handbook (EPA 8 1 6-R-OO-0 1 0, June 2000). The Handbook is
available on EPA's website at www. epa. gov/safewater/pn. html .
3. Include a discussion of the violation in its consumer confidence report (applies to community
water systems only) . Refer to §§141.151 - 141.155 or to EPA' s Preparing Your Drinking
Water Consumer Confidence Report (EPA 816-R-99-002, March 1999). This document is
available on EPA's website at www.epa.gov/safewater/ccrl .html.
4. Return to standard monitoring for lead and copper tap and WQP tap monitoring, if the system
was on a reduced monitoring schedule [see §141.87(e)(4)].
• • Note: It is important for a system to correct the problem as soon as possible, and to continue
meeting all other OWQPs. If a system operates within the OWQP ranges, or is at or above the
minimum OWQP values for all WQPs at both entry point and distribution system sampling
locations for two consecutive, 6-month monitoring periods, it can again qualify for reduced
lead and copper monitoring and WQP tap monitoring.
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How Do the Revisions Affect Systems that Are Not Required to Collect WQPs?
The LCRMR do not change which systems are required to conduct WQP monitoring. However, the
LCRMR add language that clarifies the intent of the 1991 Rule with respect to which systems are
required to conduct WQP monitoring. These clarifications are as follows:
• A system that completed treatment steps equivalent to those described in the 1991 LCR, prior
to December 7, 1992, must routinely monitor for WQPs after the State designates OWQPs
(unless it serves 50, 000 or fewer people and no longer exceeds an action level) [see
• A system that is deemed to have optimized corrosion control under §141.81(b)(3) (i.e., has
very low levels of lead and copper in the distribution system) is not required io conduct WQP
monitoring;
• A system that has installed corrosion control treatment, but is not required to conduct WQP
monitoring (because it serves 50,000 and no longer exceed the action level, or meets the
criteria of§141.81(b)(3)), must take additional actions that the State specifies which are
needed to ensure the continued operation and maintenance of the corrosion control treatment.
A State may decide that these actions should include WQP monitoring [see §141.81(b)].
The LCRMR also add language that clarifies when small and medium-size systems that were on a
reduced lead and copper tap monitoring schedule, but subsequently exceed the lead or copper action
level, must begin collecting WQP samples. For these systems, the end of the 6-month period for
WQP monitoring is synchronized with the end of the reduced lead and copper tap monitoring period
during which an AL was exceeded. This revision was made to correspond to the new OWQP
compliance procedure which is based on 6-month compliance periods. For example, if a PWS on
annual monitoring during January 1, 2001 to December 31, 2001 exceeded an AL, the corresponding
WQP monitoring period would be July 1, 2001 to December 31, 2001 [see §141.86(d)(4)(vi)(B) and
§141.87(e)(4)].
Have the Reporting Requirements Changed?
The LCRMR clarify that systems must report WQP monitoring results to the State no less frequently
than ten days after the end of each 6-month monitoring period. However, States can require systems
to report this information more frequently [see §141.90(a)(l)(viii)].
The LCRMR have not changed the requirement for systems to report violations to the State. Jf a
system determines that it is out of compliance because it has had excursions on more than 9 days in a
6-month period, the system must report this information to the State within 48 hours of making this
determination [see §141.31(b)]. The system must also deliver public notification in accordance with
the requirements that are specified in §141.201 & §§141.203 - 141.206. Community water systems
must also include a information about this violation in its consumer confidence report [see §§141.151
- 141.155].
Compliance with OWQPs as Revised by LCRMR 11 February 2001
-------
The LCRMR do not change the frequency with which States must report violations to EPA. States
must continue to report violations to EPA quarterly. EPA has developed detailed State reporting
guidance for the LCRMR. This guidance explains how to report OWQP compliance violations and
defines return to compliance for these violations. For more detail, refer to Appendix B of the State
Implementation Guidance for the Lead and Copper Rule Minor Revisions, February 2001, EPA 816-
F-99-015. A copy of this guidance is available at EPA's website at
www.epa.gov/safewater/standards.html.
What Key Points Should Systems and States Remember?
"LIT
A "daily value" is calculated for each WQP and each sampling point separately. You must also
consider all sampling points collectively to determine if the system is in compliance.
The procedure for determining the "daily value" of a WQP is based on how often the system
collects samples for that WQP at a sampling location.
A daily value is calculated for each sampling location and for each parameter, even if no
monitoring occurred at a sampling location during the 6-month period being evaluated.
Compliance determinations are always based on a 6-month period, regardless of the system's
WQP monitoring schedule.
To remain in compliance, a system cannot be outside the OWQP ranges or below the OWQP
minimum for more than a total of 9 days during a 6-month period [see § 14 1 .82(g)] . The 9 days
need not be consecutive.
Confirmation samples are no longer used, but the results of all samples collected during the 6-
month period at sites used to assess compliance with OWQPs must be reported and used in
determining compliance [see §141.82(g)].
To determine the beginning date of an excursion, use the date the sample was collected and not
the date the system or State received the results.
To determine the duration of the excursion, do not count the day the sample meets the OWQP
specifications. This sample must be for the same WQP and at the same sampling point for which
the excursion occurred [see § 14 1 .82(g)] .
Count multiple excursions that occur on a single day as one excursion.
Consider unresolved excursions from a previous monitoring period, unless the system serves
50,000 people and was not required to conduct WQP monitoring in the previous period(s)
because it was at or below the lead and copper action levels.
For a seasonal system, do not consider the days that the system is closed down and not delivering
water when calculating the length of an excursion.
Compliance with OWQPs as Revised by LCRMR 12 February 2001
-------
APPENDIX A
Examples of How to Determine
Compliance with OWQPs
Example 1: How To Determine Compliance At Different Monitoring
Locations And For Different WQPs
Example 2: How To Determine Compliance When Additional Samples
Are Not Collected In A Monitoring Period Following An
Excursion
Example 3: How To Calculate Daily Values When A System Monitors
More Frequently Than Daily At A Sampling Locations
Example 4: How To Determine Compliance When A System Monitors
Annually At A Sampling Location
Example 5: How To Determine Compliance When A System Monitors
Triennially At A Sampling Location
Example 6: How To Determine Compliance For A System That
Operates Seasonally
Example 7: How To Determine Compliance For A Small or Medium
System With Intermittent Exceedances
Compliance with OWQPs as Revised by LCRMR A-l February 2001
-------
EXAMPLE 1: How To Determine Compliance
At Different Monitoring Locations And For Different WQPs
EXAMPLE DESCRIPTION
Purpose of this example: This example is the most detailed of the 7 examples included in this
guidance. The purpose of this example is to demonstrate how to determine compliance for
different monitoring frequencies and to provide a total compliance picture for one system during
a 6-month compliance period. It is also designed to emphasize that you must evaluate each
sampling point and each WQP independently, and then look at all excursions collectively to
determine whether the system is in compliance with its OWQP requirements.
Compliance Period: January - June 2001
System description: The system has 1 entry point and 1 distribution ("tap") site. It monitors
biweekly at its entry point and every six months at its tap site. The system's treatment is pH &
alkalinity adjustment, using lime & sodium bicarbonate.
State Action: The State designates the following OWQPs:
pH = 7.5 at entry point
= 7.2 at tap site
alkalinity (mg/L as CaCO3)= 40 at entry point
= 35 at tap site
MONITORING RESULTS
A. Entry Point Monitoring pH Results
This portion of the example shows how to determine compliance for pH at the system's entry point.
Please note in the table below that the system sampled more frequently than biweekly following an
excursion. These results were also used to determine compliance. Each value below the OWQP pH
minimum of 7.5 is shown in bold. This format is similar for all examples.
Entry Point pH Results for the 6-month Monitoring Period of January - June 2001
State-specified pH minimum = 7.5
Collection
Date
Jan. 3
Jan. 17
Jan. 31
Feb. 14
Feb. 28
Result =
Daily value
8.1
8.2
7.8
7.8
7.2
Collection
Date
March 3
March 13
March 27
March 29
April 10
Result =
Daily value
7.6
7.8
7.0
7.9
7.6
Collection
Date
April 28
May 8
May 22
June 5
June 19
Result =
Daily value
7.8
7.8
7.8
8.2
7.8
Compliance with OWQPs as Revised by LCRMR
A-2
February 2001
-------
Remember, to determine the total number of days for which the system had excursions:
1. Count the first day the sample is below the pH minimum value. Use the date the sample was
collected and not the date the sample results were received.
2. Stop counting when a sample result from the same location and for the same parameter is at or
above the minimum (in this example a sample taken from the entry point and measured for pH).
Do not count the day the sample is at or above the pH minimum value in the calculation.
3. Repeat this procedure for each pH reading that falls below the pH minimum value (or 7.5 in this
example).
The following table below shows the number of days where the pH level was less than 7.5.
Number of Days that the System Had Excursions
Collection Date of Sample That Began the Excursion
Feb. 28
March 27
Total Number of Days with Excursions
Number of Days with Excursions
Feb. 28 - March 2 3 days
March 27-28 2 days
5 days
B. Distribution (Tap) Monitoring pH Results
This part of the example demonstrates how to determine compliance at the system's distribution (or tap)
sampling location. The system is on semi-annual monitoring and at a minimum is required to collect two
sets of tap samples at each location. The pH monitoring results are shown in the table below.
Distribution Sample pH Results for the 6-month Monitoring Period of January - June 2001
State-specified pH minimum = 7.2
Date
Jan. 17
May 22
May 23
Result = Daily Value
8.1
6.8
6.9
Date
May 24
May 25
May 26
Result = Daily Value
7.0
7.1
8.0
The table below summarizes the number of days where the pH level was less than 7.2.
Number of Days that the System Had Excursions
Collection Date of Sample That Began the Excursion
May 22
Total Number of Days with Excursions
Number of Days with Excursions
May 22 - 25
4 days
4 days
Compliance with OWQPs as Revised by LCRMR
A-3
February 2001
-------
C. Entry Point Monitoring Alkalinity Results
This part of the example demonstrates how to assess compliance for alkalinity at the system's entry point.
The procedure is the same as that shown in Part A.
The following table shows the alkalinity results for samples collected at the entry point.
Entry Point Alkalinity Results For January - June 2001
State-Specified Alkalinity minimum = 40 mg/L as CaCOs
Collection Date
Jan. 3
Jan. 17
Jan. 31
Feb. 14
Feb. 28
March 3
Result =
Daily Value
45
42
45
41
35
55
Collection
Date
March 13
March 27
March 29
April 10
April 11
April 24
Result =
Daily Value
50
35
45
32
45
43
Collection Date
May 8
May 22
May 23
May 25
June 5
June 19
Result =
Daily Value
45
32
33
45
40
42
The following table below shows the number of days where the alkalinity concentration was less than
State-specified minimum of 40 mg/L as CaCC>3.
Number of Days that the System Had Excursions
Collection Date of the Sample That
Began the Excursion
Feb. 28
March 27
April 10
May 22
Total
Number of Days with Excursions
Number of Days with
Feb. 28 - March 2
March 27 & 28
April 10
May 22 - May 24
Excursions
3 days
2 days
1 day
3 days
9 days
Compliance with OWQPs as Revised by LCRMR
A-4
February 2001
-------
D. Distribution (Tap) Monitoring Alkalinity Results
This part of the example demonstrates how to assess compliance for alkalinity at the tap monitoring
location. The procedure is the same as that shown in Part C. It is included to emphasize that you must
evaluate each sampling location independently [see §141.82(g)].
The table below contains the alkalinity sample results from the distribution sampling location.
Distribution (Tap) Alkalinity Results For January - June 2001
State-Specified Alkalinity Minimum = 35 mg/L as CaCOs
Collection Date
Jan. 17
May 22
May 23
Result = Daily Value
40
25
30
Collection Date
May 24
May 25
May 26
Result = Daily Value
34
30
38
The table below shows the number of days where the alkalinity concentration was less than State-specified
minimum of 35 mg/L as
Number of Days that the System Had Excursions
Collection Date of the Sample That
Began the Excursion
May 22
Total Number of Days with Excursions
Number of Days with Excursions
May 22-25 4 days
4 days
Compliance with OWQPs as Revised by LCRMR
A-5
February 2001
-------
E. Overall Compliance with Optimal WQPs
For the compliance period of January to June 2001, the system's compliance with OWQPs can be
summarized as follows:
Example System 1
Overall Compliance with WQPs for January - June 2001
(• -indicates an excursion)
Day w/ excursion
Feb. 28, 2001
Mar. 1, 2001
Mar. 2, 2001
Mar. 27, 2001
Mar. 28, 2001
Apr. 10, 2001
May 22, 2001
May 23, 2001
May 24, 2001
May 25, 2001
Entry Point
PH
•
•
•
•
•
alkalinity
•
•
•
•
•
• •
•
•
•
Tap
PH
•
•
•
•
•
•
•
•
•
alkalinity
•
•
•
•
•
•
•
•
•
Total Number of days w/ excursions =10 days
The system is out of compliance during the monitoring period of January - June 2001 because it had
excursions on more than 9 different days in a 6-month compliance period. Although, the system had no
more than 9 days with excursions for an individual parameter at a specific sampling location, when
considering all OWQP measurements, the system had excursions on 10 different days. Multiple excursions
that occur on the same day are only counted once. In this example, the system had multiple excursions on
all but one day.
Compliance with OWQPs as Revised by LCRMR
A-6
February 2001
-------
EXAMPLE 2: How To Determine Compliance When Additional Samples Are Not Collected
In A Monitoring Period Following An Excursion
EXAMPLE DESCRIPTION
Purpose of this example: This example emphasizes that an excursion continues for a given
WQP and monitoring location until the system collects a sample at the same location and for th<
same WQP that is within the OWQP range, or is at or above the minimum set by the State.
Compliance Period: January - June 2000
System description: This example focuses on the pH results at a system's two tap monitoring
sites. The State designates a minimum pH of 7.2 for both tap sampling points. The system is 01
semi-annual schedule for WQP tap monitoring.
MONITORING RESULTS
Distribution (Tap) Monitoring Alkalinity Results
The following table contains the pH sample results from the two distribution sampling locations.
Distribution pH Results For The 6-month Monitoring Period of January - June 2000
State-specified pH minimum = 7.2
Tap Sampling Point 1
Collection Date
Jan. 17
May 22
May 23
May 24
May 25
May 26
Result = Daily Value
8.1
6.8
6.9
7.0
7.1
8.0
Tap Sampling Point 2
Collection Date
Jan. 17
May 22
May 23
May 24
May 25
May 26
Result = Daily Value
8.0
6.7
No sample collected
Compliance with OWQPs as Revised by LCRMR
A-7
February 2001
-------
Tap Sampling Point 1
The system had excursions at this sampling point for 4 days (May 22 though May 25) during January
through June 2000, as shown in the table below.
Collection
Number of Days that the System Had Excursions At
Date of Sample That Began the Excursion
May 22
Total
Number of Days with Excursions
Number
May 22
the Tap for pH
of Days with
-25
Excursions
4 days
4 days
Tap Sampling Point 2
The system had excursions totaling 40 days at Tap Sampling Point 2. The duration of the excursion was
from May 22nd to the end of the 6-month period or June 30 in this example, as shown in the table below.
Number of Days that the System Had Excursions At the Tap for pH
Collection Date of Sample That Began the Excursion
May 22
Total Number of Days with Excursions
Number of Days with Excursions
May 22 -June 30 40 days
40 days
The system's last measurement at Tap Sampling Point 2 was below the OWQP pH minimum, so each
subsequent day that the system did not collect a sample was an excursion. The system was out of
compliance on the 10th day of the excursion or May 31 in this example.
Another point to this example is that the system cannot use the sample collected on May 26th at Tap
Sampling Point 1 to demonstrate that it was above the pH minimum at Tap Sampling Point 2. Each
sampling point is evaluated independently. A sample collected at one location cannot be used to
demonstrate compliance at a different sampling point.
Compliance with OWQPs as Revised by LCRMR
A-8
February 2001
-------
EXAMPLE 3: How To Calculate Daily Values When
A System Monitors More Frequently Than Daily At A Sampling Location
EXAMPLE DESCRIPTION
Purpose of this example: The purpose of this example is to describe how to calculate daily value
when a system collects more than one sample per day. This example focuses on the pH reading a
one sampling location.
System description: The system installs an in-line pH meter to record its entry point pH levels.
The State-specified pH minimum for this system is 7.5. The system records these levels 3 times
day. The results shown in the table below are for July only.
er
MONITORING RESULTS
Entry Point pH Results For The Month of July 2000
State-specified pH minimum = 7.5
Date
7/1/00
7/2/00
7/3/00
7/4/00
7/5/00
7/6/00
7/7/00
7/8/00
7/9/00
7/10/00
7/11/00
7/12/00
7/13/00
7/14/00
7/15/00
7/16/00
pH Measurements
8.1
7.9
8.1
7.9
8.1
8.1
8.2
7.8
7.8
7.3
7.9
8.2
6.8
6.7
8.3
8.2
8.0
8.0
7.9
8.2
8.0
7.9
8.1
7.8
7.7
7.6
7.9
8.0
7.4
7.4
8.2
8.0
8.0
8.0
7.9
8.0
7.9
8.0
7.7
7.8
7.6
7.2
8.0
7.9
6.7
6.8
8.2
8.0
Daily value
8.0
8.0
8.0
8.0
8.0
8.0
7.9
7.8
7.7
7.3
8.0
8.0
6.9
7.1
8.2
8.1
Date
7/17/00
7/18/00
7/19/00
7/20/00
7/21/00
7/22/00
7/23/00
7/24/00
7/25/00
7/26/00
7/27/00
7/28/00
7/29/00
7/30/00
7/31/00
—
pH Measurements
7.8
7.9
7.9
8.1
7.9
8.0
8.1
8.1
7.9
8.0
7.9
8.0
7.9
7.9
8.1
—
8.1
8.6
8.0
8.1
8.0
8.1
8.1
7.8
8.0
7.9
8.1
8.0
7.9
8.0
8.0
—
8.1
7.8
8.0
8.0
8.0
8.0
8.0
8.1
7.9
8.1
7.9
7.9
7.9
8.1
8.0
—
Daily value
8.0
8.0
8.0
8.1
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
7.9
8.1
8.0
—
Compliance with OWQPs as Revised by LCRMR
A-9
February 2001
-------
The daily value is calculated by averaging the results of each pH sample collected during the day. This
includes any additional samples that the system collects at this sampling location for pH to assess/fix the
problem. The State has discretion to delete results of obvious sampling error from the calculation [see
§141.82(g)]. Please note that to calculate the "true" pH average, you must convert pH to the hydrogen ion
concentration, take the average, and then convert the average back to pH. However, straight averaging of
pH samples (as shown in this example) is acceptable for assessing compliance. Systems that take multiple
samples per day are not expected to experience large fluctuations in pH. The two methods for calculating
pH yield similar averages when the pH readings that are being averaged fall within a limited range.
Remember: A State may develop a different formula for
determining compliance when multiple samples are
collected at the same location and on the same day if it
have outlined this procedure in its primacy package and
this alternate formula is approved by EPA.
During the month of July, the system had 3 days with excursions. This is shown in the table below.
Number of Days that the System Had Excursions
Collection
Date of Sample that Began the Excursion
July 10
July 13
Total Number of Days with Excursions
Number of Days
July 10
July 13 & 14
3
with Excursions
1 day
2 days
days
To determine whether the system is in compliance during the entire July through December 2000 time
period, the system and State must also consider whether there were any excursions during the months of
August through December [see § 141.82(g)]. In this example, assume the system did not have any
excursions for the four months of August through November. However, this system had excursions during
December. The pH monitoring results for entry point samples for December are shown in the table on the
next page.
Compliance with OWQPs as Revised by LCRMR
A-10
February 2001
-------
Entry Point pH Monitoring Results For The Month Of December 2000
State-specified pH minimum = 7.5
Date
12/1/00
12/2/00
12/3/00
12/4/00
12/5/00
12/6/00
12/7/00
12/8/00
12/9/00
12/10/00
12/11/00
12/12/00
12/13/00
12/14/00
12/15/00
12/16/00
pH Measurements
8.1
7.9
8.0
8.2
7.5
8.1
8.0
7.9
7.9
7.9
7.4
7.4
7.4
7.6
7.5
8.0
8.0
8.0
8.0
7.9
8.3
7.5
8.1
7.9
7.9
7.8
7.3
7.4
7.3
7.2
8.2
8.0
7.9
8.0
8.1
8.1
8.2
8.0
8.1
7.8
8.0
7.6
7.4
7.4
7.6
7.2
8.1
8.0
Daily value
8.0
8.0
8.0
8.1
8.0
7.9
8.1
7.9
7.9
7.8
7.4
7.4
7.4
7.3
7.9
8.0
Date
12/17/00
12/18/00
12/19/00
12/20/00
12/21/00
12/22/00
12/23/00
12/24/00
12/25/00
12/26/00
12/27/00
12/28/00
12/29/00
12/30/00
12/31/00
-
pH Measurements
8.0
8.1
7.9
7.8
8.2
8.7
7.2
7.3
7.2
7.2
7.2
7.9
8.0
7.6
7.7
-
8.1
8.1
8.6
7.5
8.4
7.3
7.2
7.3
7.4
7.2
7.2
8.1
8.3
7.6
7.6
-
8.1
8.0
7.7
7.8
8.1
7.9
7.3
7.3
7.3
7.2
7.0
7.6
7.4
7.5
7.8
-
Daily value
8.1
8.1
8.1
7.7
8.2
8.0
7.2
7.3
7.3
7.2
7.1
7.9
7.9
7.6
7.7
-
During the month of December, the system had excursions on 9 days. This is shown in the table below.
Number of Days that the System Had Excursions
Collection Date of the Sample That Began
the Excursion
December 11
December 22
Total Number of Days with Excursions
Number of Days with
December 11-14
December 22 - 26
Excursions
4 days
5 days
9 days
Compliance with OWQPs as Revised by LCRMR
A-ll
February 2001
-------
Is the system in compliance?
No, the system is out of compliance because it had excursions for a total of 12 days during the 6-month
monitoring period of July through December 2000, as follows:
Number of Days the System Had
Excursions during July - December 2000
July
August
September
October
November
December
Total
3 days
0 days
0 days
0 days
0 days
9 days
12 days
Compliance with OWQPs as Revised by LCRMR
A-12
February 2001
-------
EXAMPLE 4: How To Determine Compliance When A System
Monitors Annually At A Sampling Location
EXAMPLE DESCRIPTION
Purpose of this example: This example illustrates how to determine the "daily value" for a "tap"
(distribution) sampling point, when monitoring is conducted annually. This example focuses on one
parameter (alkalinity) for one sampling location (within the distribution system).
System description: In this example, the system serves 105 people and is on annual WQP tap
monitoring. It is required to collect 2 samples from its 1 WQP tap monitoring location. The State has
designated an alkalinity minimum of 85 mg/L as CaCO3 at this sampling location. The monitoring
period for this system is lanuary through December 2000.
MONITOPJNG RESULTS
Distribution (Tap) Alkalinity Results
For lanuary - December 2000
State-Specified Alkalinity Minimum = 85 mg/L as CaCOs
Collection Date
March 8, 2000
June 28, 2000
Monitoring Results
(in mg/L as CaCO3)
90
80
To determine compliance:
Step 1: Divide the compliance period into 6-month periods.
In this example, the two compliance periods are lanuary 1 - lune 30, 2000, and luly 1 -
December 31,2000.
Step 2: Determine if the daily values are above the State-specified minimum.
During January - June, the system had two "daily values" because both samples were
collected during the lanuary - lune compliance period. The March 8th alkalinity sample of
90 mg/L as CaCO3 was above the State-specified minimum. However, the lune 28th
alkalinity reading of 80 mg/L as CaCO3 was below the OWQP minimum. Therefore,
beginning on lune 28, 2000, the system had an excursion.
During July - December, no samples were collected. Therefore, the daily value is the most
recent sample collected during the previous monitoring period, or 80 mg/L in this example.
Step 3: Calculate the duration of the excursion.
For the January - June compliance period, the duration of the excursion is from lune 28 to
the end of the compliance period (lune 30, 2000). The length of the excursion is 3 days as
shown in the table below.
Compliance with OWQPs as Revised by LCRMR
A-13
February 2001
-------
Number of Days that the System Had Excursions during January to June
Collection Date of Sample that Began the Excursion
June 28
Total Number of Days with Excursions
Number of Days with Excursions
June 28-30 3 days
3 days
Therefore, for the compliance period of January - June, the system was in compliance, if it
had no more than 6 additional days in the monitoring period with excursions.
For July - December, the duration of the excursion is from July 1 to the end of the
compliance period of December 31, 2000. The system had an unresolved excursion from
the previous monitoring period. The excursion continues until the system collects an
alkalinity sample from the tap sampling site that is at or above the State-specified minimum.
The system did not conduct any WQP tap monitoring during the July - December 2000,
therefore, the excursion continues for the entire 6-month period. The length of the
excursion is more than 9 days (184 days to be exact), as shown in the table below.
Therefore, for the compliance period of July - December, the system is out of compliance.
• Note: A system should keep in mind that it should collect additional samples following
an excursion to assess and fix any problems. The system in this example was on annual
monitoring and met its WQP tap monitoring requirements by collecting two samples at its
tap sampling site. However, it should have continued to conduct WQP tap monitoring until
it was again operating above the State-specified alkalinity minimum.
Number of Days that the System Had Excursions during July -
Collection Date of Sample that Began the Excursion
June 28
Total Number of Days with Excursions
Number of Days
July 1- Dec 31
December
with Excursions
3 days
184 days
As a result of being out of compliance, what must this system do?
1. Report its noncompliance to the State within 48 hours of becoming aware of the violation [see
2. Deliver public notification for a LCR treatment technique violation [see §§141.201, 141.203,
141.205, and 141.206].
3 . For community water systems only, include information about this violation in its consumer
confidence report [§§141.151 - 141.155.
4. Collect WQP samples in the distribution system every six months at the standard number of sites. In
addition, if the system was on reduced lead and copper tap sample, it must now monitor every six
months at the standard number of sites [see §141.87(e)(4)]. The first 6-month monitoring period for
standard WQP and lead and copper tap monitoring is January - June 2001 in this example. The
system can again qualify for reduced WQP tap and lead and copper tap monitoring if it again meets it
OWQPs for two consecutive, 6-month periods.
Compliance with OWQPs as Revised by LCRMR
A-14
February 2001
-------
EXAMPLE 5: How To Determine Compliance When
A System Monitors Triennially At A Sampling Location
EXAMPLE DESCRIPTION
Purpose of this example: This example demonstrates how to calculate compliance for a system on a
triennial WQP tap monitoring schedule. It focuses on one WQP (orthophosphate) at one distribution
sampling location.
System description: This system uses a phosphate inhibitor. The State has set a minimum
orthophosphate concentration of 0.5 mg/L at one of its tap sampling points. The system met its OWQPs
at each of its sampling locations and can now collect WQPs within its distribution system at a frequency
of once every three years. The three-year compliance period is January 1, 2000 through December 31,
2002. This system collects a sample on March 28, 2001.
A. Compliance Periods January - June 2000 and July - December 2000
As stated in the system description above, the system is on triennial WQP tap monitoring and collects a
sample on March 28, 2001. Thus, the system is not required to and has not conducted any WQP tap
monitoring during the compliance periods of January - June 2000 and July - December 2000.
Is the system in compliance during January - June 2000 and July - December 2000?
Assume that the system has no excursions for the other WQPs at this site or at any of its other monitoring
locations. The system is in compliance for these two monitoring periods, although it has not collected a
sample during either of these compliance periods. Remember, if a system is on annual or triennial monitoring
and no sample was collected during the 6-month period that is being evaluated, the daily value is the most
recent sample collected, even if it occurred in an earlier 6-month period. As stated above in the system
description, the previous samples met the OWQP levels. In fact, the system could not be on triennial WQP
tap monitoring if it had not meet its OWQPs for 3 consecutive years.
B. Compliance Period January - June 2001
The system collected a sample on March 28, 2001 that was below the orthophosphate minimum set by the
State, and therefore, had an excursion. Assume this system took additional samples during this compliance
period as follows:
Tap Orthophosphate Results for January - June 2001
State-specified orthophosphate minimum = 0.5 mg/L
Collection Date
March 28
March 29
Result
0.4
0.4*
* Result is average of 2 samples collected on
March 29th (1st = 0.2 mg/L; 2nd = 0.6 mg/L)
Collection Date
March 30
April 1
June 28
Result
0.7
0.8
0.4
Compliance with OWQPs as Revised by LCRMR
A-15
February 2001
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Is the system in compliance during January - June 2001
Assume that the system has no excursions for the other WQPs at this site or at any of its other monitoring
locations. The system is in compliance because it had excursions on 5 days during the 6-month compliance
period. The start of the excursion is on March 28th. The system still has an excursion on March 29th because
the average of the two samples collected on this date is 0.4 mg/L. Remember, all of the samples collected at
this sampling location for orthophosphate during this 6-month period must be considered in the compliance
assessment, except those that the State has determined are sampling errors [see §141.82(g)]. Whenever, a
system collects more than one sample in a day, the daily value is the average of these samples, (unless the
State has an outlined an alternative approach in its primacy revision package that has been approved by
EPA). The sample collected on March 30tn is again above the minimum set by the State. Thus, the duration
of the first excursion is 2 days.
The system again has an excursion on June 28tn and did not collect another sample during the period of June
28 - 30. The duration of the second excursion is 3 days. The system is in compliance for the monitoring
period of January - June 2001 because the number of days with excursions did not exceed 9 days. The
table below shows the number of days with excursions.
Number of Days that the System Had Excursions
Collection Date of the Sample That Began
the Excursions
March 28
June 28
Total Number of Days with Excursions
Number of Days with Excursions
March 28 & 29 2 days
June 28-30 3 days
5 days
C. Compliance period July - December 2001
The system collected samples during this compliance period as follows. Please note that the system
collected additional samples following its excursions.
Tap Orthophosphate Results for July - December 2001
State-specified orthophosphate minimum = 0.5 mg/L
Collection Date
July 2
September 30
October 1
October 2
October 3
Result
0.6 mg/L
0.2
0.3
0.3
0.4
Collection Date
October 4
October 5
October 6
December 15
December 22
Result
0.4
0.4
0.6
0.5
0.4
Compliance with OWQPs as Revised by LCRMR
A-16
February 2001
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Is the system in compliance during July through December 2001?
No, the system is out of compliance because it had excursions on more than 9 days as shown in the table
below.
Number of Days that the System Had Excursions
Collection Date of Sample That Started the
Excursion
June 28
September 30
December 22
Total Number of Days with Excursions
Number of Days with
July 1
September 30 - Oct. 5
December 22 -31
Excursions
1 day
6 days
10 days
17 days
This system had three separate excursions during the compliance period of July through December 31,
2001. Although the first sample collected during this compliance period was above the minimum (the July
2nc* sample), the system had an excursion during the previous period for which it never collected a sample to
demonstrate it met the OWQP for that sampling point. Until the system collected this sample, it still has an
excursion. Because the system did not collect such a sample until July 2, it had an excursion on July 1.
The length of the excursion is counted from the beginning of the July to December 2001 compliance period
(or July 1st in this example) until a sample is collected at this sampling location that meets the OWQP
minimum for orthophosphate (or July 2nc*). Remember, you must consider if there are any unresolved
excursions from a previous monitoring period.
The second excursion lasted from September 30tn until October 5 . The third excursion lasted from
December 22nc* to December 31st because the system did not collect a sample subsequent to the December
22nd sample that demonstrated it met its OWQP for orthophosphate at this sampling location.
D. Compliance period January - June 2002
A system that is on reduced WQP tap, or lead and copper tap monitoring and that is out of compliance with
its OWQPs, no longer qualifies for reduced lead and copper or WQP tap monitoring. During the
compliance period of January - June 2002, the system will be on semi-annual monitoring and collecting
WQP samples at the standard number of sites. This does not impact the system's tap entry point monitoring
frequency which remains at a minimum of every two weeks.
Assume the system collects a sample on January 3rc* and June 2. Both of these samples are above 0.5
mg/L. The number of days that the system had excursions is summarized below.
Number of Days that the System Had Excursions
Collection Date of Sample That Started the Excursion
December 22
Total Number of Days with Excursions
Number of Days with Excursions
January 1-2 2 days
2 days
Compliance with OWQPs as Revised by LCRMR
A-17
February 2001
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Is the system in compliance during January through June 2002?
The system has one excursion from January 1st to January 2nc* because there is an outstanding excursion
from the previous compliance period. The system had an excursion on December 22, 2001 and the system
did not collect a sample that demonstrated it was above the minimum value for orthophosphate at its tap
sampling point until January 3rd. The length of the excursion is counted from the beginning of the January 1
to June 30, 2002 compliance period (i.e., January 1st) until a sample is collected at this sampling location
that meets the OWQP minimum for orthophosphate (or January 3rc* in this example ). The length of the
excursion is 2 days. Thus, the system is in compliance if the system does not have excursions on more
than 7 other days for other WQPs at this location or for WQPs at its entry point sampling site.
E. Compliance period July - December 2002
Assume this system collects its two samples at this location on August 29* and October 31s* and both
samples are above 0.5 mg/L.
Is the system in compliance during July - December 2002?
If the system has no more than 9 days with excursions for its other WQPs or sampling points, the system is
in compliance. During this monitoring period, the system has no excursions for orthophosphate at its tap
sampling point. In addition, if this system has been in compliance for all its WQPs at each entry point and
distribution sampling location for January - June 2002 and July - December 2002, it can collect tap WQP
samples at a reduced number during the monitoring period of January - June 2003. The system may also
reduce the frequency of lead and copper tap monitoring to annually with written approval from the State.
Compliance with OWQPs as Revised by LCRMR A-18 February 2001
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EXAMPLE 6: How To Determine Compliance For
A System That Operates Seasonally
EXAMPLE DESCRIPTION
Purpose of this example: This example focuses on compliance determinations for seasonal systems.
This example illustrates how to calculate excursions if the 6-month compliance period includes months
when the system is not in operation. It focuses on one WQP (pH) at one sampling location (entry point).
System description: This system is in operation during January 1 through March 31 of 2000 and again
in November 1 through December 31, 2000. The State has set a pH minimum of 7.0 at the system's one
entry point.
MONITORING RESULTS
A. Monitoring Results for the Compliance Period of January - June 2000
Entry Point pH Results for The 6-month Monitoring Period of January - June 2000
State-specified pH minimum = 7.0
Collection Date
January 3
January 16
January 20
February 2
Result = Daily Value
7.5
7.6
7.5
7.5
Collection Date
February 15
March 1
March 14
March 28
Result = Daily Value
7.4
7.6
6.6
6.8
Is the system in compliance during January through June 2000?
The system is out of compliance. The system had excursions on 18 days (March 14 through March 31), as
shown in the table below.
Number of Days that the System Had Excursions
Collection Date of the Sample That
Began the Excursion
March 14
Total Number of Days with Excursions
Number of Days with
March 14-31
Excursions
18 days
18 days
Compliance with OWQPs as Revised by LCRMR
A-19
February 2001
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For this system, do not consider the time period of April 1 through June 30 in the compliance assessment
because the system closed on March 31. For any seasonal system, do not consider the days that the system
is closed down and not delivering water when calculating the length of an excursion.
B. Monitoring Results for the Compliance Period of July - December 2000
The table below shows the monitoring results for July through December 2000. Remember in this example,
the system reopened on November 1, 2000.
Entry Point pH Results for The 6-month Monitoring Period of July - December 2000
State-specified pH minimum = 7.0
Collection Date
November 3
November 17
November 30
Result = Daily Value
7.3
7.3
7.2
Collection Date
December 12
December 13
December 27
Result = Daily Value
6.8
7.6
7.3
Is the system in compliance during July through December 2000?
During July through December 2000, the system had excursions on 3 days. The system was in operation and
providing water on November 1. The system had an unresolved excursion from the previous compliance
period and did not collect a sample that demonstrated that it was above the pH minimum until November 3.
Therefore, the duration of the first excursion was two days (i.e., November 1 and 2). The system was again
below the pH minimum on December 12. The system collected a sample on December 13 that showed it was
above the pH minimum set by the State. A summary of the excursions are shown below.
Number of Days that the System Had Excursions
Collection Date of the Sample That Began
the Excursion
March 28
December 12
Total Number of Days with Excursions
Number of Days with
Nov. 1 & 2
December 12
Excursions
2 days
1 day
3 days
This system is in compliance if during the period of July - December 2000, if it had no more than 6 additional
days in the monitoring period with excursions.
Compliance with OWQPs as Revised by LCRMR
A-20
February 2001
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EXAMPLE 7: How To Determine Compliance For
A Small or Medium System with Intermittent Exceedances
EXAMPLE DESCRIPTION
Purpose of this example: This example focuses on compliance determinations for a small or medium-
size system that periodically exceeds the lead or copper action level. The system is not required to
monitor for WQPs during those monitoring periods in which it is at or below both action levels. This
example illustrates how to calculate excursions if a system has monitoring periods in which it is not
required to collect WQPs. It focuses on one WQP (pH) at one sampling location (entry point).
System description:
System serves 25,000 people.
It was above the lead action level during July - December 2000.
• It had excursions on December 29 - 31, 2000 for pH at its entry point.
It was below both action levels in all monitoring conducted during 2001 and 2002, and was not
required to conduct WQP monitoring.
It conducted lead and copper annual tap monitoring during September 2003, and exceeded the
lead action level.
The State set a pH minimum of 7.5 at the system's one entry point.
The system began collecting WQP entry point samples on October 2, 2003.
MONITORING RESULTS
Monitoring Results for the Compliance Period of July - December 2003
Entry Point pH Results for The 6-month Monitoring Period of July - December 2003
State-specified pH minimum = 7.5
Collection Date
October 3
October 17
October 31
November 14
Result = Daily Value
7.7
7.6
7.7
7.7
Collection Date
November 28
December 1 1
December 24
—
Result = Daily Value
7.6
7.6
7.2
—
The LCRMR define the timing of a 6-month monitoring period for small and medium systems on reduced
lead and copper tap monitoring that are triggered into WQP monitoring because of an action level
exceedance. For these systems, the end of the 6-month period for WQP monitoring is synchronized with
the end of the reduced lead and copper tap monitoring period during which an action level was exceeded.
In this example, the lead and copper tap reduced monitoring period ended on December 2003; therefore, the
first 6-month period for which compliance with OWQPs can be determined after the system exceeds the lead
action level is July - December 2003.
Compliance with OWQPs as Revised by LCRMR
A-21
February 2001
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Is the system in compliance for July - December 2003, assuming the system had no excursions for other
OWQPs or at other sampling sites?
During the compliance period of July 1 - December 31, 2000, the system had 8 days with excursions, as
shown in the table below. The system is in compliance for the compliance period of July - December 2003, if
it had no more than 1 other day with excursions for at any other sampling location, or for a different WQP at
this sampling location.
Number of Days that the System Had Excursions
Collection Date of Sample that Began the Excursion
December 24
Total Number of Days with Excursions
Number of Days with Excursions
Dec. 24-31 8 days
8 days
Remember: An unresolved excursion from a previous
monitoring period is not considered for a small or
medium-size system if the 6-month period being
evaluated was preceded by a 6-month OWQP compliance
period in which the system was not required to conduct
WQP monitoring because it was at or below the lead and
copper action levels. This is the only instance in which
you do not consider an unresolved excursion from a
previous monitoring period.
Compliance with OWQPs as Revised by LCRMR
A-22
February 2001
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APPENDIX B
Lead and Copper Rule Minor Revisions
that Relate to OWQP Compliance and
Reporting Requirements
• • §§141.81(b)&(b)(2)
• • §141.82(g)
• • §§141.86(d)(4)(vi)(A)&(B)
• • §§141.87(d)&(e)(4)
Compliance with OWQPs as Revised by LCRMR B-l February 2001
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Appendix B
Lead and Copper Rule Minor Revisions that Relate to
OWQP Compliance and Reporting Requirements
§141.81(b): The following section clarifies that systems that have installed corrosion control treatment,
but are not required to conduct WQP monitoring must:
1. Properly operate and maintain corrosion control treatment at all times; and
2. Meet any requirements the State deems are needed to ensure this treatment is maintained.
A system is deemed to have optimized corrosion control and is not required to complete the applicable
corrosion control treatment steps identified in this section if the system satisfies one of the criteria
specified in paragraphs (b)(l) through (b)(3) of this section. Any such system deemed to have optimized
corrosion control under this paragraph, and which has treatment in place, shall continue to operate and
maintain optimal corrosion control treatment and meet any requirements that the State determines
appropriate to ensure optimal corrosion control treatment is maintained.
§141.81(b)(2): The following section requires systems that have been deemed by the State as having
optimized treatment by meeting the requirement of§141.81(b)(2) (also known as (b)(2) systems) to:
1. Continue WQP and lead and copper tap monitoring after the State sets OWQPs; and
2. Determine compliance with OWQPs using the new procedure that is explained in §141.82(g).
Note: A (b)(2) system is one that has completed treatment steps that are equivalent to those described in
the 1991 LCR prior to December 7, 1992.
Any water system may be deemed by the State to have optimized corrosion control treatment if the system
demonstrates to the satisfaction of the State that it has conducted activities equivalent to the corrosion
control steps applicable to such system under this section. If the State makes this determination, it shall
provide the system with written notice explaining the basis for its decision and shall specify the water
quality control parameters representing optimal corrosion control in accordance with §141.82(f). Water
systems deemed to have optimized corrosion control under this paragraph shall operate in compliance
with the State-designated optimal water quality control parameters in accordance with §141.82(g) and
continue to conduct lead and copper tap and water quality parameter sampling in accordance with
§141.86(d)(3) and §141.87(d), respectively. A system shall provide the State with the following
information in order to support a determination under this paragraph:
(i) The results of all test samples collected for each of the water quality parameters in §141.82(c)(3).
(ii) A report explaining the test methods used by the water system to evaluate the corrosion control
treatments listed in §141.82(c)(l), the results of all tests conducted, and the basis for the system's
selection of optimal corrosion control treatment;
(iii) A report explaining how corrosion control has been installed and how it is being maintained to
insure minimal lead and copper concentrations at consumers' taps; and
(iv) The results of tap water samples collected in accordance with §141.86 at least once every six
months for one year after corrosion control has been installed.
Compliance with OWQPs as Revised by LCRMR B-2 February 2001
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§141.82(g): The following section contains language that explains the new procedure for assessing
compliance with OWQPs.
Continued operation and monitoring. All systems optimizing corrosion control shall continue to operate
and maintain optimal corrosion control treatment, including maintaining water quality parameters at or
above minimum values or within ranges designated by the State under paragraph (f) of this section, in
accordance with this paragraph for all samples collected under §§141.87(d)-(f). Compliance with the
requirements of this paragraph shall be determined every six months, as specified under §141.87(d). A
water system is out of compliance with the requirements of this paragraph for a six-month period if it has
excursions for any State-specified parameter on more than nine days during the period. An excursion
occurs whenever the daily value for one or more of the water quality parameters measured at a sampling
location is below the minimum value or outside the range designated by the State. Daily values are
calculated as follows. States have discretion to delete results of obvious sampling errors from this
calculation.
(1) On days when more than one measurement for the water quality parameter is collected at the
sampling location, the daily value shall be the average of all results collected during the day regardless of
whether they are collected through continuous monitoring, grab sampling, or a combination of both. If
EPA has approved an alternative formula under §142.16 of this chapter in the State's application for a
program revision submitted pursuant to § 142.12 of this chapter, the State's formula shall be used to
aggregate multiple measurements taken at a sampling point for the water quality parameter in lieu of the
formula in this paragraph.
(2) On days when only one measurement for the water quality parameter is collected at the sampling
location, the daily value shall be the result of that measurement.
(3) On days when no measurement is collected for the water quality parameter at the sampling
location, the daily value shall be the daily value calculated on the most recent day on which the water
quality parameter was measured at the sample site.
Compliance with OWQPs as Revised by LCRMR B-3 February 2001
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§141.86(d)(4)(vi)(A) & (B): The following sections apply to systems that were on reduced lead and
copper monitoring schedules. They clarify what a system should do if it no longer meets its OWQPs.
(A) A small or medium-size water system subject to reduced monitoring that exceeds the lead or
copper action level shall resume sampling in accordance with paragraph (d)(3) of this section and collect
the number of samples specified for standard monitoring under paragraph (c) of this section. Such a
system shall also conduct water quality parameter monitoring in accordance with §141.87(b), (c) or (d) (as
appropriate) during the monitoring period in which it exceeded the action level. Any such system may
resume annual monitoring for lead and copper at the tap at the reduced number of sites specified in
paragraph (c) of this section after it has completed two subsequent consecutive six-month rounds of
monitoring that meet the criteria of paragraph (d)(4)(i) of this section and/or may resume triennial
monitoring for lead and copper at the reduced number of sites after it demonstrates through subsequent
rounds of monitoring that it meets the criteria of either paragraph (d)(4)(iii) or (d)(4)(v) of this section.
(B) Any water system subject to the reduced monitoring frequency that fails to operate at or above the
minimum value or within the range of values for the water quality parameters specified by the State under
§141.82(f) for more than nine days in any six-month period specified in §141.87(d) shall conduct tap
water sampling for lead and copper at the frequency specified in paragraph (d)(3) of this section, collect
the number of samples specified for standard monitoring under paragraph (c) of this section, and shall
resume monitoring for water quality parameters within the distribution system in accordance with
§ 141.87(d). Such a system may resume reduced monitoring for lead and copper at the tap and for water
quality parameters within the distribution system under the following conditions:
(7) The system may resume annual monitoring for lead and copper at the tap at the reduced number of
sites specified in paragraph (c) of this section after it has completed two subsequent six-month rounds of
monitoring that meet the criteria of paragraph (d)(4)(ii) of this section and the system has received written
approval from the State that it is appropriate to resume reduced monitoring on an annual frequency.
(2) The system may resume triennial monitoring for lead and copper at the tap at the reduced number
of sites after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either
paragraph (d)(4)(iii) or (d)(4)(v) of this section and the system has received written approval from the
State that it is appropriate to resume triennial monitoring.
(3) The system may reduce the number of water quality parameter tap water samples required in
accordance with §141.87(e)(l) and the frequency with which it collects such samples in accordance with
§141.87(e)(2). Such a system may not resume triennial monitoring for water quality parameters at the tap
until it demonstrates, in accordance with the requirements of §141.87(e)(2), that it has re-qualified for
triennial monitoring.
Compliance with OWQPs as Revised by LCRMR B-4 February 2001
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§141.87(d): The following section requires systems to determine compliance with OWQPs using the new
procedure, explains when the 6-month period for assessing compliance begins, and describes when a
system that exceeds the lead or copper action level should begin WQP monitoring.
Monitoring after State specifies water quality parameter values for optimal corrosion control. After the
State specifies the values for applicable water quality control parameters reflecting optimal corrosion
control treatment under § 141.82(f), all large systems shall measure the applicable water quality
parameters in accordance with paragraph (c) of this section and determine compliance with the
requirements of § 141.82(g) every six months with the first six-month period to begin on the date the State
specifies the optimal values under §141.82(f). Any small or medium-size system shall conduct such
monitoring during each six-month period specified in this paragraph in which the system exceeds the lead
or copper action level. For any such small and medium-size system that is subject to a reduced
monitoring frequency pursuant to §141.86(d)(4) at the time of the action level exceedance, the end of the
applicable six-month period under this paragraph shall coincide with the end of the applicable monitoring
period under §141.86(d)(4). Compliance with State-de signaled optimal water quality parameter values
shall be determined as specified under §141.82(g).
§141.87(e)(4): The following section applies to systems that were on reduced WQP tap monitoring. It
clarifies what a system should do if it is no longer in compliance with its OWQPs.
Any water system subject to the reduced monitoring frequency that fails to operate at or above the
minimum value or within the range of values for the water quality parameters specified by the State in
§141.82(f) for more than nine days in any six-month period specified in §141.82(g) shall resume
distribution system tap water sampling in accordance with the number and frequency requirements in
paragraph (d) of this section. Such a system may resume annual monitoring for water quality parameters
at the tap at the reduced number of sites specified in paragraph (e)(l) of this section after it has completed
two subsequent consecutive six-month rounds of monitoring that meet the criteria of that paragraph and/or
may resume triennial monitoring for water quality parameters at the tap at the reduced number of sites
after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either paragraph
(e)(2)(i) or (e)(2)(ii) of this section.
§141.90(a)(l)(viii): This section describes the revised reporting requirements pertaining to WQP
monitoring results.
A water system shall report the results of all water quality parameter samples collected under §141.87(c)-
(f) during each six-month monitoring period specified in §141.87(d) within the first 10 days following the
end of the monitoring period unless the State has specified a more frequent reporting requirement.
§142.16(d)(l)(n): This section requires a State to provide in its primacy application, an explanation of
how it will calculate compliance with OWQPs if it elects to use an alternative approach than averaging
when multiple samples are collected per day at the same sampling location and for the same WQP.
Section 141.82(g) — Designating an alternative approach for aggregating multiple measurements collected
during the same day for a water quality parameter at a sampling location, if the State elects to adopt a
formula other than the one specified in §141.82(g)(l) of this chapter.
Compliance with OWQPs as Revised by LCRMR B-5 February 2001
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