[Federal Register Volume 85, Number 212 (Monday, November 2, 2020)]
[Proposed Rules]
[Pages 69272-69276]
[FR Doc No: 2020-23933]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0972; Project Identifier MCAI-2020-01091-T]
RIN 2120-AA64

Airworthiness Directives; ATR--GIE Avions de Transport
R[eacute]gional Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to supersede Airworthiness Directives (AD)
2000-23-26, AD 2018-14-11, and AD 2019-13-04, which apply to ATR--GIE
Avions de Transport R[eacute]gional Model ATR72 airplanes. AD 2019-13-
04 requires revising the existing maintenance or inspection program, as
applicable, to incorporate new or more restrictive maintenance
instructions and airworthiness limitations. Since the FAA issued AD
2019-13-04, the FAA has determined that new or more restrictive
airworthiness limitations are necessary. This proposed AD would require
revising the existing maintenance or inspection program, as applicable,
to incorporate new or more restrictive airworthiness limitations, as
specified in a European Union Aviation Safety Agency (EASA) AD, which
will be incorporated by reference. The FAA is proposing this AD to
address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by December
17, 2020.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax:<PHONE_NUMBER>.
     Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

    For the EASA material identified in this proposed AD that will be
incorporated by reference (IBR), contact the EASA, Konrad-Adenauer-Ufer
3, 50668 Cologne, Germany; telephone +49 221 8999 000; email
<EMAIL_ADDRESS>internet www.easa.europa.eu. You may find this IBR
material on the EASA website at https://ad.easa.europa.eu.
    For the ATR service information identified in this proposed AD,
contact ATR--GIE Avions de Transport R[eacute]gional, 1 All[eacute]e
Pierre Nadot, 31712 Blagnac Cedex, France; telephone +33 (0) 5 62 21 62
exception occurred on : 2020-23933.htm
exception occurred on : 2020-23933.htm
21; fax +33 (0) 5 62 21 67 18; email aircraft.com">[email protected]aircraft.com; internet https://www.atr-aircraft.com.
    You may view this IBR material at the FAA, Airworthiness Products
Section, Operational Safety Branch, 2200 South 216th St., Des Moines,
WA. For information on the availability of this material at the FAA,
call<PHONE_NUMBER>. It is also available in the AD docket on the
internet at https://www.regulations.gov by searching for and locating
Docket No. FAA-2020-0972.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0972; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this NPRM, any comments received, and other information. The street
address for Docket Operations is listed above. Comments will be
available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Shahram Daneshmandi, Aerospace
Engineer, Large Aircraft Section, International Validation Branch, FAA,
2200 South 216th St., Des Moines, WA 98198; telephone and fax 206-231-
3220; email<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2020-0972; Project Identifier
MCAI 2020-01091-T'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
the proposal because of those comments. Except for Confidential
Business Information (CBI) as described in the following paragraph, and
other information as described in 14 CFR 11.35, the FAA will post all
comments we receive, without change, to https://www.regulations.gov,
including any personal information you provide. The agency will also
post a report summarizing each substantive verbal contact we receive
about this proposed AD.

Confidential Business Information

    CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to
Shahram Daneshmandi, Aerospace Engineer, Large Aircraft Section,
International Validation Branch, FAA, 2200 South 216th St., Des Moines,
WA 98198. Any commentary that the FAA receives which is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.

Discussion

    The FAA issued AD 2019-13-04, Amendment 39-19677 (84 FR 35028, July
22, 2019) (``AD 2019-13-04''), for certain ATR--GIE Avions de Transport
R[eacute]gional Model ATR72 airplanes. AD 2019-13-04 requires revising
the existing maintenance or inspection program, as applicable, to
incorporate new or more restrictive maintenance instructions and
airworthiness limitations. The FAA issued AD 2019-13-04 to address
fatigue cracking and damage in principal structural elements, which
could result in reduced structural integrity of the airplane. AD 2019-
13-04 specifies that accomplishing the revision required by paragraph
(g) of that AD terminates all requirements of AD 2000-23-26, Amendment
39-11999 (65 FR 70775, November 28, 2000) (``AD 2000-23-26''), AD 2008-
04-19 R1, Amendment 39-16069 (74 FR 56713, November 3, 2009) (``AD
2008-04-19 R1''), and AD 2018-14-11 Amendment 39-19331 (83 FR 34031,
July 19, 2018) (``AD 2018-14-11'');. AD 2008-04-19 R1 was superseded by
AD 2020-09-16, Amendment 39-19912 (85 FR 29596, May 18, 2020). This
proposed AD would therefore supersede AD 2000-23-26, AD 2018-14-11, and
AD 2019-13-04.

Actions Since AD 2019-13-04 Was Issued

    Since the FAA issued AD 2019-13-04, the FAA has determined that new
or more restrictive airworthiness limitations are necessary.
    The EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2020-0173, dated August 5, 2020
(``EASA AD 2020-0173'') (also referred to as the Mandatory Continuing
Airworthiness Information, or ``the MCAI''), to correct an unsafe
condition for all ATR--GIE Avions de Transport R[eacute]gional Model
ATR72 airplanes.
    Airplanes with an original airworthiness certificate or original
export certificate of airworthiness issued after December 12, 2019 must
comply with the airworthiness limitations specified as part of the
approved type design and referenced on the type certificate data sheet;
this AD therefore does not include those airplanes in the
applicability.
    This proposed AD was prompted by a determination that new or more
restrictive airworthiness limitations are necessary. The FAA is
proposing this AD to address fatigue cracking and damage in principal
structural elements, which could result in reduced structural integrity
of the airplane. See the MCAI for additional background information.

Related IBR Material Under 1 CFR Part 51

    EASA AD 2020-0173 describes new or more restrictive airworthiness
limitations for airplane structures and safe life limits.
    This AD would also require ATR ATR72 Time Limits Document, Revision
16, dated January 30, 2018, which the Director of the Federal Register
approved for incorporation by reference as of August 26, 2019 (84 FR
35028, July 22, 2019).
    This material is reasonably available because the interested
parties have access to it through their normal course of business or by
the means identified in the ADDRESSES section.

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of another

country, and is approved for operation in the United States. Pursuant
to the FAA's bilateral agreement with the State of Design Authority,
the FAA has been notified of the unsafe condition described in the MCAI
and service information referenced above. The FAA is proposing this AD
because the FAA has evaluated all pertinent information and determined
an unsafe condition exists and is likely to exist or develop on other
products of the same type design.

Proposed AD Requirements

    This proposed AD would retain the requirements of AD 2019-13-04.
This proposed AD would also require revising the existing maintenance
or inspection program, as applicable, to incorporate new or more
restrictive airworthiness limitations, which are specified in EASA AD
2020-0173 described previously, as incorporated by reference. Any
differences with EASA AD 2020-0173 are identified as exceptions in the
regulatory text of this AD.
    This proposed AD would require revisions to certain operator
maintenance documents to include new actions (e.g., inspections).
Compliance with these actions is required by 14 CFR 91.403(c). For
airplanes that have been previously modified, altered, or repaired in
the areas addressed by this proposed AD, the operator may not be able
to accomplish the actions described in the revisions. In this
situation, to comply with 14 CFR 91.403(c), the operator must request
approval for an alternative method of compliance according to paragraph
(n)(1) of this proposed AD.

Explanation of Required Compliance Information

    In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA initially worked with Airbus and EASA to develop a
process to use certain EASA ADs as the primary source of information
for compliance with requirements for corresponding FAA ADs. The FAA has
since coordinated with other manufacturers and civil aviation
authorities (CAAs) to use this process. As a result, EASA AD 2020-0173
will be incorporated by reference in the FAA final rule. This proposed
AD would, therefore, require compliance with EASA AD 2020-0173 in its
entirety, through that incorporation, except for any differences
identified as exceptions in the regulatory text of this proposed AD.
Using common terms that are the same as the heading of a particular
section in the EASA AD does not mean that operators need comply only
with that section. For example, where the AD requirement refers to
``all required actions and compliance times,'' compliance with this AD
requirement is not limited to the section titled ``Required Action(s)
and Compliance Time(s)'' in the EASA AD.
    Service information specified in EASA AD 2020-0173 that is required
for compliance with EASA AD 2020-0173 will be available on the internet
at https://www.regulations.gov by searching for and locating Docket No.
FAA-2020-0972 after the FAA final rule is published.

Airworthiness Limitation ADs Using the New Process

    The FAA's process of incorporating by reference MCAI ADs as the
primary source of information for compliance with corresponding FAA ADs
has been limited to certain MCAI ADs (primarily those with service
bulletins as the primary source of information for accomplishing the
actions required by the FAA AD). However, the FAA is now expanding the
process to include MCAI ADs that require a change to airworthiness
limitation documents, such as airworthiness limitation sections.
    For these ADs that incorporate by reference an MCAI AD that changes
airworthiness limitations, the FAA requirements are unchanged.
Operators must revise the existing maintenance or inspection program,
as applicable, to incorporate the information specified in the new
airworthiness limitation document. The airworthiness limitations must
be followed according to 14 CFR 91.403(c) and 91.409(e).
    The previous format of the airworthiness limitation ADs included a
paragraph that specified that no alternative actions (e.g.,
inspections) or intervals may be used unless the actions or intervals
are approved as an alternative method of compliance (AMOC) in
accordance with the procedures specified in the AMOCs paragraph under
``Other FAA Provisions.'' This new format includes a ``New Provisions
for Alternative Actions, and Intervals'' paragraph that does not
specifically refer to AMOCs, but operators may still request an AMOC to
use an alternative action or interval.

Costs of Compliance

    The FAA estimates that this proposed AD affects 23 airplanes of
U.S. registry. The FAA estimates the following costs to comply with
this proposed AD:
    The FAA estimates the total cost per operator for the retained
actions from AD 2019-13-04 to be $7,650 (90 work-hours x $85 per work-
hour).
    The FAA has determined that revising the existing maintenance or
inspection program takes an average of 90 work-hours per operator,
although the agency recognizes that this number may vary from operator
to operator. In the past, the agency has estimated that this action
takes 1 work-hour per airplane. Since operators incorporate maintenance
or inspection program changes for their affected fleet(s), the FAA has
determined that a per-operator estimate is more accurate than a per-
airplane estimate.
    The FAA estimates the total cost per operator for the new proposed
actions to be $7,650 (90 work-hours x $85 per work-hour).

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect on the States, on the relationship
between the national Government and the States, or on the distribution
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed
regulation:
    (1) Is not a ``significant regulatory action'' under Executive
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by:
0
a. Removing Airworthiness Directive (AD) 2000-23-26, Amendment 39-11999
(65 FR 70775, November 28, 2000); AD 2018-14-11, Amendment 39-19331 (83
FR 34031, July 19, 2018); and AD 2019-13-04, Amendment 39-19677 (84 FR
35028, July 22, 2019), and
0
b. Adding the following new AD:

ATR--GIE Avions de Transport R[eacute]gional: Docket No. FAA-2020-
0972; Project Identifier MCAI-2020-01091-T.

(a) Comments Due Date

    The FAA must receive comments by December 17, 2020.

(b) Affected ADs

    (1) This AD replaces AD 2000-23-26, Amendment 39-11999 (65 FR
70775, November 28, 2000) (``AD 2000-23-26'').
    (2) This AD replaces AD 2018-14-11, Amendment 39-19331 (83 FR
34031, July 19, 2018) (``AD 2018-14-11'').
    (3) This AD replaces AD 2019-13-04, Amendment 39-19677 (84 FR
35028, July 22, 2019) (``AD 2019-13-04'').

(c) Applicability

    This AD applies to ATR--GIE Avions de Transport R[eacute]gional
Model ATR72 airplanes, certificated in any category, with an
original airworthiness certificate or original export certificate of
airworthiness issued on or before December 12, 2019.

(d) Subject

    Air Transport Association (ATA) of America Code 05, Time Limits/
Maintenance Checks.

(e) Reason

    This AD was prompted by a determination that new or more
restrictive airworthiness limitations are necessary. The FAA is
issuing this AD to address fatigue cracking and damage in principal
structural elements, which could result in reduced structural
integrity of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified,
unless already done.

(g) Retained Maintenance or Inspection Program Revision, With No
Changes

    This paragraph restates the requirements of paragraph (g) of AD
2019-13-04, with no changes. For airplanes with an original
airworthiness certificate or original export certificate of
airworthiness issued on or before January 30, 2018: Within 90 days
after August 26, 2019 (the effective date of AD 2019-13-04), revise
the existing maintenance or inspection program, as applicable, to
incorporate the information specified in ATR ATR72 Time Limits
Document, Revision 16, dated January 30, 2018. The initial
compliance time for doing the tasks is at the time specified in ATR
ATR72 Time Limits Document, Revision 16, dated January 30, 2018, or
within 90 days after August 26, 2019, whichever occurs later, except
as provided by paragraphs (h) and (i) of this AD.

(h) Retained Initial Compliance Times for Certain Tasks, With No
Changes

    This paragraph restates the requirements of paragraph (h) of AD
2019-13-04, with no changes. For airplanes with an original
airworthiness certificate or original export certificate of
airworthiness issued on or before January 30, 2018: For
accomplishing airworthiness limitations (AWL) and certification
maintenance requirement (CMR)/maintenance significant item (MSI)
tasks identified in figure 1 to paragraph (h) of this AD, the
initial compliance time is at the applicable time specified in the
airworthiness limitations section (ALS) of the ATR ATR72 Time Limits
Document, Revision 16, dated January 30, 2018, or at the applicable
compliance time in figure 1 to paragraph (h) of this AD, whichever
occurs later.
[GRAPHIC] [TIFF OMITTED] TP02NO20.000

(i) Retained Initial Compliance Time: One-Time Initial Threshold, With
No Changes

    This paragraph restates the requirements of paragraph (i) of AD
2019-13-04, with no changes. For airplanes with an original
airworthiness certificate or original export certificate of
airworthiness issued on or before January 30, 2018: For CMR task
220000-5, a one-time initial threshold, as specified in ATR ATR72
Time Limits Document, Revision 16, dated January 30, 2018, is
allowed as specified in figure 2 to paragraph (i) of this AD.

[GRAPHIC] [TIFF OMITTED] TP02NO20.001

(j) Retained Restrictions on Alternative Actions and Intervals With a
New Exception

    This paragraph restates the requirements of paragraph (j) of AD
2019-13-04, with a new exception. Except as required by paragraph
(k) of this AD, after the existing maintenance or inspection program
has been revised as required by paragraph (g) of this AD, no
alternative actions (e.g., inspections) and intervals may be used
unless the actions and intervals are approved as an alternative
method of compliance (AMOC) in accordance with the procedures
specified in paragraph (n)(1) of this AD.

(k) New Maintenance or Inspection Program Revision

    Except as specified in paragraph (l) of this AD: Comply with all
required actions and compliance times specified in, and in
accordance with, European Union Aviation Safety Agency (EASA) AD
2020-0173, dated August 5, 2020 (``EASA AD 2020-0173'').
Accomplishing the maintenance or inspection program revision
required by this paragraph terminates the requirements of paragraph
(g) of this AD.

(l) Exceptions to EASA AD 2020-0173

    (1) Where EASA AD 2020-0173 refers to its effective date, this
AD requires using the effective date of this AD.
    (2) The requirements specified in paragraphs (1) and (3) of EASA
AD 2020-0173 do not apply to this AD.
    (3) Paragraph (4) of EASA AD 2020-0173 specifies revising ``the
approved AMP'' within 12 months after its effective date, but this
AD requires revising the existing maintenance or inspection program,
as applicable, to incorporate the ``limitations, tasks and
associated thresholds and intervals'' specified in paragraph (4) of
EASA AD 2020-0173 within 90 days after the effective date of this
AD.
    (4) Except as provided by paragraph (2) of EASA AD 2020-0173,
the initial compliance time for doing the tasks specified in
paragraph (4) of EASA AD 2020-0173 is at the applicable ``associated
thresholds'' specified in paragraph (4) of EASA AD 2020-0173, or
within 90 days after the effective date of this AD, whichever occurs
later.
    (5) Where table 1 of EASA AD 2020-0173 specifies a compliance
time of ``without exceeding the previous threshold and interval as
specified in TLD Revision 16'' for this AD use ``without exceeding
the compliance times specified in paragraph (g) of this AD.''
    (6) The provisions specified in paragraphs (5) and (6) of EASA
AD 2020-0173 do not apply to this AD.
    (7) The ``Remarks'' section of EASA AD 2020-0173 does not apply
to this AD.

(m) New Provisions for Alternative Actions and Intervals

    After the maintenance or inspection program has been revised as
required by paragraph (k) of this AD, no alternative actions (e.g.,
inspections) or intervals, are allowed unless they are approved as
specified in the provisions of the ``Ref. Publications'' section of
EASA AD 2020-0173.

(n) Other FAA AD Provisions

    The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager,
Large Aircraft Section, International Validation Branch, FAA, has
the authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19,
send your request to your principal inspector or local Flight
Standards District Office, as appropriate. If sending information
directly to the Large Aircraft Section, International Validation
Branch, send it to the attention of the person identified in
paragraph (o)(4) of this AD. Information may be emailed to<EMAIL_ADDRESS>Before using any approved AMOC, notify your
appropriate principal inspector, or lacking a principal inspector,
the manager of the local flight standards district office/
certificate holding district office.
    (2) Contacting the Manufacturer: For any requirement in this AD
to obtain instructions from a manufacturer, the instructions must be
accomplished using a method approved by the Manager, Large Aircraft
Section, International Validation Branch, FAA; or EASA; or ATR--GIE
Avions de Transport R[eacute]gional's EASA Design Organization
Approval (DOA). If approved by the DOA, the approval must include
the DOA-authorized signature.

(o) Related Information

    (1) For EASA AD 2020-0173, contact the EASA, Konrad-Adenauer-
Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email
<EMAIL_ADDRESS>internet www.easa.europa.eu. You may find this
EASA AD on the EASA website at https://ad.easa.europa.eu.
    (2) For the ATR service information identified in this AD
contact ATR--GIE Avions de Transport R[eacute]gional, 1 All[eacute]e
Pierre Nadot, 31712 Blagnac Cedex, France; telephone +33 (0) 5 62 21
exception occurred on : 2020-23933.htm
exception occurred on : 2020-23933.htm
62 21; fax +33 (0) 5 62 21 67 18; email aircraft.com">[email protected]aircraft.com; internet https://www.atr-aircraft.com.
    (3) You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 2200 South 216th St.,
Des Moines, WA. For information on the availability of this material
at the FAA, call<PHONE_NUMBER>. This material may be found in the AD
docket on the internet at https://www.regulations.gov by searching
for and locating Docket No. FAA-2020-0972.
    (4) For more information about this AD, contact Shahram
Daneshmandi, Aerospace Engineer, Large Aircraft Section,
International Validation Branch, FAA, 2200 South 216th St., Des
Moines, WA 98198; telephone and fax<PHONE_NUMBER>; email
<EMAIL_ADDRESS>
    Issued on October 23, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2020-23933 Filed 10-30-20; 8:45 am]
BILLING CODE 4910-13-P


C:\ dmautop\ temp\ dwcgi 9574 1072814222 123071000. wpd MEMORANDUM TO: Jesse Pritts and Pat Harrigan, EPA EAD CC: Kathy Monk, EPA EAD FROM: Betsy Bicknell, ERG DATE: February 3, 2003 SUBJECT: Brief: National Sediment Quality Survey ( 12/ 2001)

This memorandum is a partial response to Technical Direction received from Jesse Pritts on January 15, 2003. Among other things, ERG was directed to review briefs prepared by EAD. These briefs evaluate the utility of data sources for determining specific industrial categories or facilities that may pose a risk to human health and the environment or may be significant dischargers of toxic or conventional pollutants to waters of the U. S. due to wastewater and stormwater discharges. This memorandum addresses the brief describing the National Sediment Quality Survey ( 12/ 2001).

Overview EPA compiled existing data on concentrations of contaminants in sediments and tissue residue. The data reflected samples collected from 1990 to 1999, representing about 9 percent of river reaches. Using sediment chemistry and chemical toxicity information along with the sediment and tissue concentration measurements, EPA classified each sampling station by the probability of adverse effects on aquatic life or human health. A list, by chemical, of the frequency of detection in sediment and tissue, is included in the brief. ( Table C 3).

Comments ° This study identified geographical areas of concern. Identification of contaminant sources for each area of concern would be quite difficult. Instead, EPA may be able to identify chemicals of concern ( nationally) and investigate the types of industries that are likely sources of discharges of these chemicals.

° Metals were frequently detected in sediment and tissue. Because metals are naturally occurring in sediment and tissue, concentrations must be used to evaluate these results. C:\ dmautop\ temp\ dwcgi 9574 1072814222 123071000. wpd ° Pesticides were frequently detected in sediment and tissue. Many are no longer in commercial use and would likely have no active discharge.

° Mercury was frequently detected in sediment and tissue. Atmospheric deposition is a major route for introduction of mercury into the environment. Also, EPA's mercury program has targeted environmental reductions.

° The remaining results could be sorted to identify chemicals potentially of concern, followed by additional investigation of discharge sources of these chemicals.

° There is no direct connection between chemicals found in contaminated sediment and point source dischargers.

Short term Follow up ( February  March, 2003)

° Review complete report and contact authors to determine if " chemicals of concern" were identified. If so, use OPPT tools and other sources to identify potential sources for active point source discharges on the chemicals of concern.

° Determine if the analyses in this report have been used in the OPPT programs ( e. g., PBT chemicals) to target chemical specific work.

° Compare the factors used to weight sediment contaminants to the " toxic weighting factors" EAD has used to analyze the cost effectiveness of effluent limitations guidelines and standards and the environmental indicators included in RSEI. Also compare these factors to the chemical ranking factors used by OPPT.

Long term Follow up ( after March 2003)

° If report authors and OPPT have not prioritized chemicals potentially of concern, with respect to sediment contamination, evaluate the study results to make preliminary identifications.

° Use OPPT tools and other sources to identify potential sources for active point source discharges on the chemicals of concern.

° Consider incorporating sediment hazard weighting factors into other risk screening tools ( TWF, RSEI) if they are not yet included.