NC0030210_Staff Comments_19961011

WDES DOCYMEMI' SCANNIM6 COVER SHEET
NPDES Permit:
NCO030210
Charlotte / Mallard Creek WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Staff Comments,
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
October 11, 1996
This document is printed oa reuse papE"r - ignore any
ooateat oa the reYerse side

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State of North Carolina
Department of Environment, •
Health and Natural ResourcesA419�1
•
Division of Water Quality 40 IL
James B. Hunt, Jr., Governor -D E H N R
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
October 11,1996
Ms. Jennifer Boe
Black & Veatch
8604 Cliff Cameron Drive, Suite 164
Charlotte, NC � 8269
Subject: 1Draft EAs - Mallard Creek WWTP EA & Reuse Pumping Station and Pipeline EA
CMUD, Mecklenburg County
Dear Ms. Boe:
The Division of Water Quality has reviewed the Draft Environmental Assessments your
firm prepared for the projects identified above. I am sorry it has taken so long to finish these
reviews within ,our Division. All Division comments are included in this letter.
The documents were, overall, relatively adequate in most areas; however, there were some
serious concerns raised by staff that need to be addressed. They pertain to the completeness of
the presentation and interpretation of available water quality data, discussion of water quality
impacts, the details of the alternatives analysis, secondary environmental impacts, and the inter-
connection between these projects. At this time, please keep the projects separate as they are
now.
I look forward to seeing eight copies of the revised documents once these issues have
been addressed. In order to expedite the review of these projects, a second review around to
DWQ will be conducted as the documents are circulated to DEHNR agencies (a 3-4 week
process). The final stage will then be Clearinghouse review and issuance of a Finding of No
Significant Impact (FONSI) (a 2 month process), if appropriate.
If you have any questions, please give me a call at [phone], Ext. 567.
Sincerely,
t
Michelle L. Su bbe, AICP
Environmental Specialist
mis:NrnAvdea.doc
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P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX [phone]
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Ms. Boe
Mallard Creek W W'IP Eris
10/11/96 page 2
DWQ Comments
Mallard Creek WWTP Expansion & Upgrade
Environmental Assessment
1. Section V, Secondary Impacts, of the document addresses increased plant operations and
land use changes. It is stated in the document that "land use changes will result in
changes of non -point loading patterns", that "new development will be forced to halt if no
additional municipal wastewater treatment capacity is provided" and that "enforcement of
the county's land use plan, zoning regulations and floodplain management program will
muiimize adverse impacts from development". No discussion of urban stormwater control
or non point source pollution prevention is discussed.
It is clear that the County is planning for growth by this project - therefore, growth is
expected and dependent on this project. In fact, it has been shown (and supported by
recent court cases such as Sunset Beach) that not only are treatment plant expansions a
response to growth, but that growth in communities are in uc or encouraged by
expansions to vital public services expansions, like treatment plant upgrades.
In order to meet the requirements of the North Carolina Environmental Policy Act
(NCEPA), growth that will be allowed or encouraged by this project is considered a
secondary impact of the project and needs to be discussed. Along with defining what that
growth I may encompass, all the secondary impacts of that growth on the water quality in
the local area must be defined and discussed in the document also. This includes
stormwater impacts of the anticipated growth. The document needs to specify how the
County plans to mitigate the impacts of this increased urbanization on stream health.
Additional information should be provided on the following: (1) the extent and type of
additional development that will be encouraged or supported by the expansion, including
a map of the Mallard Creek Service Area; (2) the nature and water quality implications of
adverse impacts, including some discussion of specific pollutants and hydromodification
due to stormwater inputs; (3) a description of programs and policies currently in place in
each relevant jurisdiction to deal with stormwater impacts and the protection of riparian
vegetation. Policies and management strategies should be summarized in the
environmental assessment --simply referring to other documents is not adequate.
How will the following known contributors to declining stream health from urbanization
be contt?olled by the County in the service area of the project:
a. ink runoff volumes and velocities (leading to increased frequency and severity of
flooding),
b. increased erosion of streambanks, steep slopes, in -stream and riparian habitats and
unvegetated areas,
C. increased water temperature and scouring of streambeds,
d. increased siltation of downstream riparian vegetation and habitats,

Ms. Boe
Mallard Creek WWTP EAs
10/11/96 page 3
e. increased level of pollutants, and
f. decreased streamflow during drought due to reduced infiltration and low groundwater
levels.
It is well -understood that the non -point loading pattern on surface water bodies does, in
fact, increase as urbanization occurs. It is also well -documented that overall stream health
declines with the increased density of urbanization (due to the above contributors). These
potential impacts on water quality are potentially significant if not mitigated. Coupled with
other high levels of urbanization elsewhere in the Yadkin and Catawba River Basins, the .
potential for cumulative in
on surface waters from non -point source pollution is very
great.
The purpose of an environmental assessment is to determine whether or not the
environmental impacts from a proposed project will be significant. This includes primary,
secondary and cumulative -impacts. If they are found to be significant, then an
Environmental Impact Statement will be needed. If the impacts are not deemed to be
significant, or if they can be mitigated to the extent that they are not significant, then a
Finding of No Significant impact (FONSI) can be issued. Without addressing the
secondary and cumulative stormwater and surface water impacts of growth planned for as
a result of this project, this determination cannot be made and the project cannot receive a
FONSL
2. The review of existing water quality data is inadequate and incomplete. Neither insfream
monitoring data collected by the facility nor any DWQ data are mentioned. As written,
the only water quality data presented are chemical and biological data collected by
Mecklenburg County. These data are listed in the Appendix but are not adequately
summarized in the text. The chemical data presented for Mallard Creek cover only 1996,
although some 1994 data are presented for other streams in the watershed. There is no
explanation of whether all available data collected by the county are presented or whether
some information has been omitted A map showing the location of the sampling sites
would aid in the interpretation of the data. For your assistance in providing this
information in the EA, please see the attached Catawba River Basinwide Water Quality
Management Plan.
3. Information on the current effluent characteristics and compliance history of the plant
should be presented, as well as information on any expected changes in influent
characteristics (for instance, changes due to increases in industrial wasteflow).
No hydrologic information on the receiving stream is presented (for instance, average
and 7Q10 flows). It is critical that the document take note of the nature of low flows in
Mallard Creek. The instream waste concentration currently exceeds 90%, and a doubling
of flow is likely to substantially increase the period of time during which the creek is
effluent dominated.

Ms. Boe
Mallard Creek WWTP EAs
10/11/96 page 4
4. This EA needs to address the plan to reuse the wastewater as a part of the "mitigation"
associated with the expansion. Or, as an alternative to discharging 100% of the requested
expansion all year round and the fact that the reuse will be the highest during the low flow
months, thereby, decreasing the potential for negative impact to the receiving stream.
5. Figure 1. The document should include an area map which clearly indicates the location
of Mallard Creek and the Rocky River, the subject facility and other nearby facilities
such as Cabarrus County's Rocky River Regional WWTP. Figure 1 is not adequate in
this regard.
6. P. 3 The document states that the plant will discontinue biological phosphorus removal
and will continue to operate denitrification treatment if it is cost effective. In late
August, DWQ received a report from Mecklenburg County documenting what it
considgrs to be elevated nutrient levels downstream of several CMUD facilities,
including the Mallard Creek plant. Given the anticipated changes in nutrient removal,
the EA should address Mecklenburg County's concerns in more detail. The report should
specify the expected concentrations of nitrogen and phosphorus in the effluent, as well as
the expected instream concentrations downstream of the discharge. Potential
environmental impacts should be discussed.
7. P. 4 Metals and toxicity issues should be mentioned in the discussion of effluent limits.
8. P. 4 The section on the need for the project is very general. No information is presented
on the projected population to be served or the anticipated increase in wastewater
generation.
9. P. 5-6 1The alternatives analysis contains numerous assertions with little supporting
information. For example, the document states that diversion of wasteflow to the
McAlpine WWTP is 'not cost effective', but there is no further elaboration. While tying
onto the Cabarrus County Rocky River Regional WWTP is mentioned, the possibility of
an outfall on the Rocky River is not discussed. The discussion of the no -action
alternative states that 'new development will be forced to halt' under this scenario. While
the rate of development may indeed be much slower in the absence of additional
treatment capacity and the nature of that development will differ, it is not likely that
development will halt. The situation should be described in more detail.
10. P. 7 Plans for water reuse should be discussed further. Although this is the subject of a
separate EA, the potential for reuse to mitigate the impact of the expanded discharge
must be discussed in the subject document as well. Estimates of the expected amount of
reuse should be clearly stated. The pumping capacity for the proposed reuse project is 3
MGD, but the current draft does not mention the actual volume of water to be reused, nor
discuss the implications of this for the re-rating/expansion.

Ms. Boe
Mallard Creek WWW EAs
10/11/96 page 5
11. P. 7 The document notes that DWQ has been contacted regarding the need for approval
of an interbasin transfer (from the Catawba basin to the Yadkin). CMUD should be
informed that interbasin transfer issues are handled by the Division of Water Resources,
not DWQ. DWR should be consulted on this as soon as possible. It is not immediately
apparent why authorization would.not be required for the interbasin transfer that would
result from re -rating.
12. P. 8 �Ie document states that construction activities will be located at a sufficient
distance from Mallard Creek to avoid significant surface water impacts during
construction. No information is presented on the actual distances involved, nor is a site
map included in the document.
13. P. 9 The document states that water quality concerns in Mallard Creek include nutrients
and sediment. BOD and toxics must also be addressed.
14. P.10 See previous comments on water quality data.
15. P. 10 Reference is made to violations of fecal coliform limits in groundwater. If this is
important enough to mention in the document, efforts to deal with this contamination
should also be discussed, as should any implications for the proposed project.
16. P.14 The document states that effluent water quality will be improved and that water
quality in Mallard Creek will not be degraded despite a doubling of permitted flow. No
data pn current or projected effluent quality are presented to support these claims.
Except for ammonia, effluent limits at 12 MGD are likely to be identical to current
limits. The document states that the assimilative capacity of the stream is adequate. It
should also note that, as far as BOD is concerned, this is largely the result of increased
aeration due to higher stream velocities at the higher wasteflows. As mentioned above,
the stream (7Q10=0.64 cfs) is likely to be effluent dominated a higher proportion of the
time. No support is given for the statement that the project will have no impact on
aquatic wildlife. The comments of several agencies, included in the Appendix, note the
lack of available information on this issue. It would be helpful to summarize important
agency comments in the body of the report.
17. P. 17 While increased expenditures for plant operations and maintenance are certainly
likely, these do not constitute secondary impacts on the environment.

Ms. Boe
Mallard Creek WWTP EAs
10/11/96 page 6
DWQ Comments
Mallard Creek WWTP Reuse Pumping Station and Pipeline
Environmental Assessment
1. Table 1 on Page 8 provides anticipated limits. New rules indicate that the following
changes should be made to the anticipated limits:
BOD daily maximum should be 15.0 mg/l
NH3 as N daily max. should be 6.0 mg/1
fecal monthly average should be 14.0 mg/1
2. The document should reference our Division's water quality classification status for the
surface waters affected by the project in the Yadkin River Basin:
Mallard Creek - Class C
Stony Creek - Class C
Little Stony Creek - Class C
UT to �tony Creek - Class C
UT's to Mallard Creek - Class C
3. Under the wetlands discussion on page 16, it states that the pipeline activities will occur
in upland areas within existing NCDOT rights -of -way, "in which no wetlands are
located". How was that determined? The project description in Section H states that the
"pipeline will be installed using open -trench methods ... under creek beds." A statement
regarding presence or absence of wetlands must be substantiated by a wetlands
deline on in the field. Please provide clarification.
This statement appears to conflict with statements provided in Section J., Water Supplies
(page 18), regarding the "anticipated 404 permit and 401 Certification" being required
for the areas crossed by pipelines. Please clarify and correct both these sections. Also,
consider removing the discussion of the 404 and 401 permits from the Water Supplies
section and place within either subsection B., Wetlands, or create a new subsection
(within Section IV, Environmental Consequences) titled "Water Quality" to address
general questions about how the project will protect water quality.
Any impacts to waters or wetlands associated with the project will likely qualify for a
Nationwide Permit 12 (NWP 12). Note, however, that both the US Army Corps of
Engineers and the NC Division of Water Quality currently are modifying the nationwide
permit and associated Section 401 certification conditions. These changes will take
effect in January 1997. If you need any assistance with this matter, please contact John
Domey or Steve Kroeger, DWQ Water Quality Laboratory, [phone].

Ms. Boe
Mallard Creek WWTP EAs
10/11/96 page 7
I' trenching in creeks for installation of the reuse lines it is incorrect to
4. Also, in regards to tre g,
say that (on page 19, under the Wildlife subsection), that "all activity related to
construction of the ... pipeline facilities will occur on ... NCDOT rights -of -way and will
not involve additional clearing ... therefore, wildlife and their habitat will not be affected
by the ... pipeline project." The document references proposed construction activities in
the creeks in several locations. Land clearing .Bdfl be involved in the project, therefore,
an estimate of impact to wildlife habitat and shellfish needs to be discussed, and if
necessary, mitigation added to the project to reduce the significance of any impacts.
5. It is ommended that more discussion be provided in Section IV to address how the
star ds of treatment for reclaimed water will allow spraying this water on public
space (the golf course) and that certain restrictions on usage (i.e. rate of application,
buffers adjacent to open water, etc.) are required in the NPDES permit, so that no harm
will occur to human health (from contact), surface water quality, groundwater quality,
wildlife, shellfish or their habitat, eutrophication, etc. It needs to be clear in the
document (since not everyone who reads this EA knows the Reuse Rules) how this
project will not harm human health or environmental quality. In actuality, the
restrictions on reused water usage that will be specified in the permit make up the
majority of the "mitigation measures" for this project. Therefore, even though it may
seem redundant, please specify in Section IV, under all appropriate subheadings, how the
water will be treated, handled and used to prevent any impacts to these resource areas.
This is already done fairly well in the Toxic Substances subsection (page 19).
in a document ' ' tin and force main
6. Provide wording th doc e t recogn�ng that the pump station
require permitting, as does the spray irrigation on the golf course.
cc: Coleen Sullins
Ruth Swanek
mis:\malardea.doc