19910326 Ver 1_Scoping Comments_19940818

w.
State of North Carolina ""J"
Department of Environment, -W JW
Health and Natural Resources A
4
Division of Environmental Management
James B. Hunt, Jr., Governor ® F== e
Jonathan B. Howes, , Secretary ? V
A. Preston Howard, Jr., P.E., Director
August 18, 1994
MEMORANDUM
TO: Lois Cashel!
FROM: Steve W. Tedder, Water Quality Section Chie
SUBJECT: EIS Scoping - Application for Non-
Project Use of Project Lands and Waters at Gaston and
Roanoke Rapids Project (FERC No. 2009)
The Division's Water Quality Section has reviewed the scoping
document (FEA) for the subject project. Our Section is primarily
concerned with the potential effects of the proposed withdrawal on
downstream water quality in the Roanoke River. We would like to
request that the following information be presented in the EIS
that the FERC prepares for this project:
1) . Flow and Water Use in the Lower Roanoke River Basin -
Increased water consumption in the lower Roanoke River Basin will
significantly reduce flows below the project in the future.
Increased water consumption upstream will reduce the inflow into
project, and increased pollution will diminish the quality of the
inflow. The EIS should present an analysis of the critical flows
for protecting aquatic habitat and water quality downstream of the
proposed project in terms of these future water use scenarios.
Similarly, the EIS should provide a discussion of the projected
water use needs in the lower Roanoke River Basin to supply future
industry, agriculture, population growth and assimilative
capacity. Such an analysis should consider not only the large
permitted and documented water withdrawals, but the cumulative
consumptive effect of small agricultural withdrawals in the lower
Roanoke River Basin. Because the demand for irrigation water (and
indeed all other water uses) is highest during dry periods, the
effect of water withdrawals will likely be greatest, and the
potential for adverse water quality impacts be most severe,' during
critical flow periods. The EIS must evaluate water needs and
availability during these peak periods.
In order to project conditions as they will likely occur, the EIS
must model all reasonable future uses, additional pollutants that
will enter the system and the new and more stringent rules
regarding minimum flow, dissolved oxygen, and year-round flows
needed for fish and wildlife that will come with relicensing. The
model must consider all relevant factors, including temperature
and salinity. The model must also measure the margin of flow
remaining to allow industrial expansion, increased irrigation,
P.O. Box 29535, Raleigh, North Carolina 27626-05351 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post-consumer paper
municipal water use, the enhancement of fish and wildlife, the
resources of Albemarle Sound, and otherwise.
The model results must then be applied against appropriate
biological measures for items affecting fish, wildlife, and other
natural resources. For example, some previous models have merely
counted minimum flow days, 9 rather than scientifically assessing
likely harm to fish and wildlife from further reductions in
already inadequate flow. The EIS must also calculate the
additional costs of industrial pollution control at certain water
quality conditions, and other socioeconomic costs of lower water
quality. This project assessed cumulatively represents a
reduction in flows of up to 30% during low flow conditions. (NCD
Vol VII, page 99; FERC Official Transcript of Scoping Comments,
Raleigh, N.C.)
2) Estuarine Water Ouality - The FEA concluded that unavoidable
adverse impacts to the environment associated with the Lake Gaston
pipeline would result from an overall reduction in flows to the
Roanoke River Basin downstream from Lake Gaston. This overall
reduction in flows may have significant impacts on the
phytoplankton growth in the estuarine portions of the Roanoke
River, into the Albemarle Sound. Reduced flows may translate into
a longer detention time for algae to be in contact with nutrients
which may result in extensive algal blooms and depressed dissolved
oxygen concentrations. In addition, the FEA recognizes a need to
simulate the estuary. The FEA indicates that any net reduction in
downstream flows from future consumptive demands may result in
measurable increases in salinity concentrations in the estuary.
Consequently, DEM recommends that a model for the estuarine
portion of the Roanoke River be developed. This model should
extend in the Roanoke River from the Town of Hamilton to include
the estuarine portion of the Chowan and Pasquotank River Basins
into the Albemarle Sound. The model should be able to predict
instream dissolved oxygen, nutrients, salinity, and phytoplankton
concentrations. The model should be able to determine the
response of the estuary to various flow regimes, nutrient and BOD
loads originating in the upper portions of the watershed.
Specifically, at all flow regime scenarios, predictive modeling
should determine the critical levels for dissolved oxygen and
nutrient concentrations, the duration of contravention's,
phytoplankton and salinity peaks and temperature. Lake levels
should also be specified for all flow regime scenarios.
As a result of limited resources, this modeling has not yet been
undertaken by NCDEM. However, it should be conducted as part of
the EIS provided the analysis was developed under very close
technical review by DEM at all stages of development, including
selection of the modeling tool, study plan and product delivery
options. In addition, the development of a QUAL2E model should be
explored to simulate the impact of BOD loads in the estuary
originating from the Northwest River and from North Landing River
in Virginia.
2

3) Waste Assimilation/Dissolved Oxygen - DEM concurs with the
FEA that potential wasteload assimilation impacts should be
evaluated further, particularly given the uncertainty of future
water availability in the lower Roanoke River Basin. As discussed
on page 63 of the FEA, the existing DO model developed by DEM is
not field calibrated. Recognizing there is a need for a better
predictive modeling tool, DEM plans to develop a field calibrated
QUAL2E model by the end of 1995. This QUAL2E model extends from
Roanoke Rapids to Hamilton and will simulate instream DO
concentrations.
This model should be validated as part of the EIS process. This
analysis should be developed under very close technical review by
DEM at all stages of development. Concerning model prediction
error, the model that DEM will develop will only explore: 1) the
probability of violating the stream DO water quality standard at
key locations; and 2) the confidence in the model by examining the
sensitivity of the model output to the model assumptions or input
parameters. This will be achieved through Sensitivity Analysis,
Monte Carlo Simulations and First Order Analysis. Given the
importance of the Lake Gaston withdrawal decision, this model
should be statistically validated in FERC's analysis that will be
part of this EIS.
Due to time constraints and staff resources, DEM will not be able
to validate this model in the near future. Model validation is
the process of testing a mathematical model in a scenario
different from the calibration scenario to ascertain that the
predictive error is acceptable. Statistical tests are used in
model validations. Based on preliminary analyses, the QUAL2E
model of the Roanoke River is expected to demonstrate that the
oxygen-consuming assimilative capacity of the river is
compromised. Flow augmentation in the Lower Roanoke River may be
necessary to allow future increased demands on the assimilative
capacity of the river. The model could be used under several
"hypothetical" scenarios which simulate these increased demands.
The model could help to establish the required minimum releases
that would "support" certain wastewater flows downstream of the
dam.
4. Secondary and Cumulative Impacts - The availability of a new
60 MGD water supply source would dramatically increase the
potential for population growth in Virginia Beach and its
surrounding areas. The development associated with this growth
could, in turn, adversely impact water quality in areas of the
Chowan-Pasquotank watershed, including the Currituck Sound. The
EIS should assess the secondary impacts of the proposed project on
water quality in North Carolina. The EIS should also discuss the
proposed mitigation measures required to ensure that secondary
growth will be managed to prevent degradation of water uses in
North Carolina. The FEA has suggested that growth will occur in
the area regardless of whether the project is approved. If that
3
is the case, it is clear that alternative water sources are
readily available or that the area has no additional needs. If
additional water from the project is in fact needed to ensure
growth, then that growth must be assessed in the EIS.
5. Wetland Im ap cts - The potential project impacts on wetlands
along portions of the Roanoke River Basin should be addressed in
the EIS. The attached memo from John Dorney summarizes
information which is needed to address wetland impacts.
6. Water Ouality Issues
Virginia Beach proposes to
with flow release from the
Kerr Lake would be affectei
quality impacts from those
evaluated and discussed in
UT)stream of Lake Gaston - Because
mitigate the proposed 60 mgd withdrawal
upstream Kerr Reservoir, lake levels in
3 by the proposed project. The water
reduced water levels should be clearly
the EIS.
7. Protection of Water Quality Standards - From the perspective
of the Division of Environmental Management, the most critical
questions that should be addressed in an EIS are whether state
water quality standards will be protected if the project is
approved and whether opportunities for enhancing water quality
will be maintained. In the past, environmental decisions on
protecting water quality standards were based on only a few
parameters. If simple dilution calculations and simple models
indicated that metals, temperature, and dissolved oxygen would be
protected, then the projects were usually allowed. Today,
projects cannot be approved until assurance is given that all
standards will be protected. These include biological diversity,
antidegradation, and assurances that all existing uses of the
waters are protected. Uses cannot be diminished without meeting
the conditions provided in the state's antidegradation policy
contained in 15A NCAC 2B .0201. (Copy Attached.) Opportunities
for enhancing water quality and uses are also extremely important.
This is critical in the Roanoke and Albermarle Sound because of
the environmental and economic importance of the resource and the
threatened nature of the habitat. Both the Federal and State
Governments have concluded that there is now frequently inadequate
water to meet the needs of the aquatic environment. In making
decisions for 401 certifications, the Division considers (among
other things) whether existing uses such as pollutant removal,
wildlife habitat, bank stabilization, and aquatic life habit are
present and must make the final decision considering if any of
these or other uses would be diminished by the action. The EIS
should also determine if existing uses along the riparian areas of
lakes and streams in the Roanoke River basin would similarly be
affected by the project. Similarly, the EIS must evaluate the
degree to which enhancement opportunities will be limited.
8. Mitigation Deficiencies - The Water Quality Section would
like to make it clear that the "mitigation proposal°, purportedly
design to compensate for withdrawals of 60 mgd during the striped
bass spawning period is grossly insufficient. As proposed, the
4
w J
flow augmentation would have a goal to "not cause the loss of any
augmented spawning flow days which would otherwise be caused by
the City's withdrawal." This leaves open the possibility that
when a spawning day is already "lost" because there is already
inadequate water in the river, the city could seriously exacerbate
an existing water quality problem. Unless the City of Virginia
Beach were to be held responsible for augmentation of the total
amount withdrawn whenever flows are below targets throughout the
year, the Water Quality Section does not consider the proposed
augmentation proposal as adequate compensation.
9. Basinwide Planning - In preparation of the Environmental
Impact Statement, the FERC should be cognizant of the fact that
North Carolina is in the process of preparing a basinwide water
quality management plan for the Roanoke River basin. This plan is
being prepared under North Carolina's basinwide approach to water
quality management which began in 1990. A program description
document (54 pages) and an eight-page paper describing the
basinwide approach are enclosed.
Under this approach, basinwide water quality management plans are
being prepared for each of the 17 major river basins in North
Carolina by the year 1999. The plans are being prepared pursuant
to a basinwide permitting schedule established in January 1990.
Water quality and aquatic resources will be assessed
simultaneously throughout an entire river basin, leading to the
development of basinwide water quality management plans and
strategies.
Determination and distribution of waste assimilative capacity in a
basin, and development of innovative management strategies that
protect surface water quality in the basin while allowing for
economic growth are very important objectives of this approach
(see page of Program Description document). North Carolina does
not have the resources, at this time to model all 37,000 miles of
rivers and streams in the state and determine their waste
assimilative capacity. Instead, the state is using the basinwide
approach to prioritize water quality issues and focus its
attention and resources on those priority issues and water bodies.
In the Roanoke River basin, determining waste assimilative
capacity to support downstream uses and future growth and
development in the basin are key topics of the upcoming plan. A
critical factor in these determinations includes river flow. It
is unclear to what extent flow will be a limiting factor to long-
term growth and protection of downstream uses. The quantity of
water that may be removed from the river at any one time is
unclear, and no determination has been made of what amount of
water is needed to maintain enough assimilative capacity to
protect downstream uses and provide for future economic growth in
the basin. In preparing its basin plan, DEM would utilize the
best available information and attempt to make these
determinations. The resultant plan would then be used to guide
5

DEM's water quality program duties and responsibilities in the
basin including monitoring, permitting, planning and compliance.
Work is already under way for completion of the Roanoke River
Basinwide Management Plan. According to the NPDES permitting
schedule set in 1990, all NPDES permits in the Roanoke River basin
are due to expire and be renewed in 1997 starting in January of
that year. DEM has also completed intensive water quality
monitoring in the basin for inclusion in the basin plan and to
support limited water quality modeling efforts. A draft basinwide
management plan is due for completion in July 1995. Present plans
call for taking the plan to public meetings in January 1996. The
plan is due to be finalized in July 1996.
With limited resources, the extent of waste assimilative modeling
would be restricted, and many of the strategies to be presented in
the plan would be based on best professional judgment. However,
the basin plan for Roanoke Basin could be enhanced considerably by
data generated by the proposed EIS, particularly the information
requested in items 1 through 3, above. This is particularly
important in this case because of the upcoming project
relicensing. Analysis for this purpose will begin in a few months
and will direct effects on the river basins planning for decades
to come.
The development of these models and studies is therefore critical
before any determination can be made of whether the largest
consumptive use in the basin can be allowed. We stand ready, and
strongly encourage, the interchange of ideas and data on these
critical questions. Working together, we can maximize limited
resources and work towards a wise use of our natural resources.
CC: Steve W. Tedder
Roger Thorpe
Greg Thorpe
Boyd DeVane
John Dorney
Alan Clark
Ken Eagleson
Don Safrit
Ruth Swanek
Juan Mangles
6