Federal Register / Vol. 65, No. 12 / Wednesday, January 19, 2000 / Notices 2953

effects of grass/turf in decreasing runoff

(EPA, 1998, EPA–730–F–97–002, PB97–

137806, page 15). This division by six

was used to calculate the potential

exposure via surface water from the

Compass turf application, 0.06 ppb / 6

= 0.010 ppb. Therefore, the highest

potential exposure to trifloxystrobin

from surface water is from the Compass

ornamental use, 0.017 ppb.

b. Estimated ground water

concentrations. The screening

concentration in ground water (SCIGROW) estimated ground water

concentrations for the proposed Flint

and Compass uses also contributed little

to the overall exposure. The estimated

concentrations were not adjusted for the

estimated market share or percentage of

use area. In each use scenario, the

concentration of trifloxystrobin in

ground water was predicted to be below

1 part per trillion. The highest estimated

concentration of trifloxystrobin in the

ground water was 0.000587 ppb

provided by the Compass turf use.

c. Drinking water levels of concern—

acute exposure. The estimated

maximum concentrations of

trifloxystrobin in surface water at Peak

Day–0 was 2.48 ppb (GENEEC) and

0.000587 ppb in ground water (SCIGROW). The acute drinking water level

of concentration (DWLOC) values were

calculated and compared to these

estimated water concentrations. Per EPA

preference, the 10–day multiple dosing

rat teratology study defined the acute

NOAEL at 10 mg/kg/day.

From the acute dietary exposure

analysis, the lowest Margin of Exposure

(MOE) from the use of trifloxystrobin

was 1,960 at the 99.9th percentile for the

U.S. population and all population

subgroups. This indicates a food

exposure of less than 0.0051 mg/kg/day

for all populations. Based on the EPA’s

‘‘Interim Guidance for Conducting

Drinking Water Exposure and Risk

Assessments’’ document (draft 12/2/97),

acute drinking water levels of concern

(DWLOCacute) were calculated for

trifloxystrobin. The lowest acceptable

Margin of Exposure (MOE) for any

pesticide is 100. This value was used in

the DWLOC calculations as a

conservative approach. Based on this

analysis, trifloxystrobin estimated

surface water (2.48 ppb) and ground

water concentrations (0.000587 ppb) do

not exceed the calculated acute DWLOC

values (3,497, 3,496, 2,997, 997).

Therefore, trifloxystrobin exposures

would not exceed the exposure

allowable by the risk cup.

d. Chronic exposure. The estimated

maximum concentrations of

trifloxystrobin in surface water at Day–

56/3 was 0.017 ppb (GENEEC) and

0.000587 ppb in ground water (SCIGROW). The chronic DWLOC values

were calculated and compared to these

estimated water concentrations. The

chronic reference dose for

trifloxystrobin is 0.025 mg/kg body wt/

day, based upon the findings in the rat

chronic toxicity study. From the chronic

dietary exposure analysis, an exposure

estimate of 0.000140 mg/kg body wt/day

was determined for the U.S. population

and > 0.00032 for all subgroups. Using

this information, chronic drinking water

levels of concern (DWLOCchronic) were

calculated for trifloxystrobin. The

trifloxystrobin estimated ground water

(0.000587 ppb) and surface water (0.017

ppb) concentrations do not exceed the

calculated chronic DWLOC values (872,

870, 746, 247). Therefore, trifloxystrobin

exposures would not exceed the

exposure allowable by the risk cup.

2. Non-dietary exposure. Non-dietary

exposure to trifloxystrobin is considered

negligible as the chemical is intended

primarily for commercial and

agricultural use. Post-application reentry exposure to homeowners from

professional use on residential

ornamentals is considered negligible.

For workers handling this chemical,

acceptable margins of exposure (in the

range of thousands) have been obtained

for both acute and chronic scenarios.

D. Cumulative Risk

Consideration of a common

mechanism of toxicity is not appropriate

at this time since there is no information

to indicate that toxic effects produced

by trifloxystrobin would be cumulative

with those of any other types of

chemicals. Furthermore, the

oximinoacetate is a new type of

fungicide and no compound in this

general chemical class currently has a

significant market share. Consequently,

Novartis is considering only the

potential exposure to trifloxystrobin in

its aggregate risk assessment.

E. Safety Determination

1. U.S. population. Using the

conservative exposure assumptions

described above and based on the

completeness and reliability of the

toxicity data base for trifloxystrobin,

Novartis has calculated aggregate

exposure levels for this chemical. The

calculation shows that only 0.5% of the

RfD will be utilized for the U.S.

population based on chronic toxicity

endpoints. EPA generally has no

concern for exposures below 100

percent of the RfD because the RfD

represents the level at or below which

daily aggregate dietary exposure over a

lifetime will not pose appreciable risks

to human health. Novartis concludes

that there is a reasonable certainty that

no harm will result from aggregate

exposure to trifloxystrobin residue.

2. Infants and children.

Developmental toxicity, manifested as

reduced weaning pup weight, enlarged

thymus, or fused sternabrae, was

observed in the teratology study and 2–

generation rat reproduction studies at

maternally toxic doses. All of these

findings are judged to be non-specific,

secondary effects of maternal toxicity.

The lowest NOAEL for developmental

toxicity was established in the rat

reproduction study at 5 mg/kg, a level

that is likely to be an overly low

estimate (as a result of dose gap) but is

still higher than the chronic NOAEL of

2.5 mg/kg on which the RfD is based.

Using the same conservative exposure

assumptions as employed for the

determination in the general population,

Novartis has calculated that the percent

of the RfD that will be utilized by

aggregate exposure to residues of

trifloxystrobin is only 2.1% for nonnursing infants (> l year old) (the most

impacted sub-population). Therefore,

based on the completeness and

reliability of the toxicity data base and

the conservative exposure assessment,

Novartis concludes that there is a

reasonable certainty that no harm will

result to infants and children from

aggregate exposure to trifloxystrobin

residues.

F. International Tolerances

No Codex MRL’s have been

established for residues of

trifloxystrobin. Flint has been registered

on pome fruit in Switzerland, and

Stratego (trifloxystrobin +

propiconazole) has been registered on

cereals in Switzerland.

[FR Doc. 00–1214 Filed 1–18–00; 8:45 am]

BILLING CODE 6560–50–F

ENVIRONMENTAL PROTECTION

AGENCY

[FRL–6526–1]

Proposed Prospective Purchaser

Agreement Pursuant to the

Comprehensive Environmental

Response, Compensation and Liability

Act of 1980 (CERCLA), as Amended by

the Superfund Amendments and

Reauthorization Act, OronogoDuenweg Mining Belt Superfund Site,

Jasper County, Missouri

AGENCY: Environmental Protection

Agency.

ACTION: Notice; request for public

comment.

2954 Federal Register / Vol. 65, No. 12 / Wednesday, January 19, 2000 / Notices

SUMMARY: Notice is hereby given that a

proposed prospective purchaser

agreement associated with the OronogoDuenweg Mining Belt Superfund Site,

located in Jasper County, Missouri, was

executed by the Agency on December

29, 1999. The Site is part of an inactive

lead and zinc mining area known as the

Tri-State Mining District. The Site

encompasses approximately 270 square

miles, with large volumes of abandoned

and uncontrolled mining wastes spread

throughout the Site. The mining wastes

at the Site contain elevated levels of

lead, which is a hazardous substance as

defined by the Comprehensive

Environmental Response, Compensation

and Liability Act of 1986 (‘‘CERCLA’’).

The Prospective Purchaser Agreement

would resolve certain potential EPA

claims under CERCLA against the

Missouri Highway Transportation

Commission (‘‘MHTC’’), the prospective

purchaser (‘‘the purchaser’’).

The settlement requires the purchaser

to utilize large quantities of materials

from past mining activities as fill, which

would become part of the construction

of the ‘‘Rangeline Bypass.’’ The

purchaser must ensure that upon

completion of construction, clean cover

is in place over all mine materials. The

purchaser will handle the mine material

in accordance with a work plan that is

designed to ensure that contamination is

not spread during construction. The

purchaser agrees to provide to EPA

access to the property. EPA may at any

time conduct an inspection of the

property, including sampling, to ensure

the work is being performed in

accordance with the work plan.

For thirty (30) days following the date

of publication of this document, the

Agency will receive written comments

relating to the proposed settlement.

DATES: Written comments must be

submitted on or before February 18,

2000.

ADDRESSES: Comments should

reference the ‘‘Oronogo-Duenweg

Mining Belt Superfund Site’’ and should

be forwarded to D. Mark Doolan,

Remedial Project Manager, U.S.

Environmental Protection Agency,

Region VII, 901 North 5th Street, Kansas

City, Kansas 66101. A copy of the

proposed agreement may be obtained

from Venessa Cobbs (913) 551–7630.

FOR FURTHER INFORMATION CONTACT:

David Cozad, Senior Associate Regional

Counsel, United States Environmental

Protection Agency, Region VII, 901

North 5th Street, Kansas City, Kansas

66101, (913) 551–7587.

Dated: January 4, 2000.

Dennis Grams,

Regional Administrator, Region 7.

[FR Doc. 00–1213 Filed 1–18–00; 8:45 am]

BILLING CODE 6560–50–P

ENVIRONMENTAL PROTECTION

AGENCY

[FRL–6526–3]

Water Quality Criteria: Notice of Draft

Ambient Water Quality Criteria for

Dissolved Oxygen (Saltwater): Cape

Cod to Cape Hatteras

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice of availability of Draft

Ambient Water Quality Criteria for

Dissolved Oxygen (Saltwater): Cape Cod

to Cape Hatteras.

SUMMARY: Pursuant to section 304(a)(1)

of the Clean Water Act (CWA), the

Environmental Protection Agency

announces the availability of a draft

document titled, Draft Ambient Water

Quality Criteria for Dissolved Oxygen

(Saltwater): Cape Cod to Cape Hatteras.

The EPA is considering using the values

presented in this document as its

recommended national 304(a) criteria

for dissolved oxygen in saltwater. These

304(a) criteria would provide

recommended guidance values for

States, Territories, and authorized

Tribes to use in adopting water quality

criteria to protect aquatic life from acute

and chronic effects of low dissolved

oxygen. Under the CWA, States,

Territories, and Tribes are to adopt

water quality criteria to protect

designated uses. As the document is

currently written, these water quality

criteria would apply only to the

Virginian Province (Cape Cod to Cape

Hatteras), but with appropriate

modifications, they may be applicable to

other regions. While these criteria

would constitute EPA’s scientific

recommendations regarding ambient

concentrations of dissolved oxygen that

protect saltwater aquatic life, these

criteria are not regulations; thus they

would not impose legally binding

requirements on EPA, States,

Territories, Tribes, or the public, and

might not apply to a particular situation

based upon the circumstances. State,

Territories, and authorized Tribes retain

the discretion to adopt, where

appropriate, other scientifically

defensible water quality standards that

differ from these recommendations. EPA

may change these 304(a) criteria in the

future.

These draft criteria were under

development prior to the Agency’s

revision and implementation of its

current processes for notice of data

availability and criteria development

(see Federal Register, December 10,

1998, 63 FR 68354 and in the EPA

document titled, National

Recommended Water Quality—

Correction EPA 822–Z–99–001, April

1999). As indicated in the December 10,

1998 FR document, the Agency believes

it is important to provide the public

with an opportunity to submit scientific

information on draft criteria, even

though we are not required to invite nor

respond to specific issues. Therefore,

EPA will review and consider

significant scientific information

submitted by the public that might not

have otherwise been identified during

development of these criteria, or in the

external peer review. The external peer

review comments and EPA’s responses

are available in the Water Docket. After

review of the submitted significant

scientific information, EPA will publish

a revised document, or publish a

document indicating its decision not to

revise the document.

This draft document has been

approved for publication by the Office

of Science and Technology, Office of

Water, U.S. Environmental Protection

Agency. Mention of trade names or

commercial products does not

constitute endorsement or

recommendation for use.

DATES: All significant scientific

information must be submitted to the

Agency within 45 days after publication

of this document in the Federal Register

under docket number W–99–22. The

Administrative Record supporting this

guidance document, including results of

the peer review is available at the Water

Docket, Room EB–57, Environmental

Protection Agency, 401 M Street SW,

Washington, DC 20460 on Monday

through Friday, excluding Federal

holidays, between 9:00 a.m. and 4:00

p.m. For access to docket materials call

(202) 260–3027 for an appointment. A

reasonable fee will be charged for

photocopies. Any scientific information

submitted should be adequately

documented and contain enough

supporting information to indicate that

acceptable and scientifically defensible

procedures were used and that the

results are likely reliable.

ADDRESSES: Copies of the complete

document, titled Draft Ambient Water

Quality Criteria for Dissolved Oxygen

(Saltwater): Cape Cod to Cape Hatteras

can be obtained from EPA’s Water

Resource Center by phone at 202–260–

7786, or by e-mail to center.waterresources@epa.gov or by conventional

mail to EPA Water Resource Center, RC–