NC0000353_Memo_19950213

State of North Carolina
Department of Environment,
Health and Natural Resources ATA
Division of Environmental Management
James B. Hunt, Jr., Governor ED E H N FI
Jonathan B. Howes, Secretary
Nann B. Guthrie, Regional Manager
Asheville Regional Office
WATER QUALITY SECTION
February 13 , 1995
MEMORANDUM
TO: Dana Bolden
Permits and Engineering it
THROUGH: Forrest R. Westall /
Regional Water Qua Supervisor
FROM: Michael R. Parker '
Environmental Chemist
SUBJECT: NPDES Staff Reports
The Feldspar Corporation NC0000353
Unimin Corporation-Crystal NC0084620
Mitchell County
Attached to this memo are NPDES staff reports for the
subject facilities. Unimin Corporation-Crystal Operations
wastewater is currently being treated by The Feldspar Corporation
and is proposing to discharge. Unimin Corporation and The
Feldspar Corporation have entered into an agreement in which The
Feldspar Corporation will give up 50 lbs of fluoride and Unimin
Corporation will assume this 50 lbs and discharge this amount .
There will not be a change in the total amount of fluorides being
discharged to the North Toe River. We have discussed all of
these limits with Unimin Corporation and they are agreeable to
them.
If you have questions or if I can be of assistance, please
call me at 704/251-6208 .
Interchange Building,59 Woodfin Place,Asheville,N.C.28801 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50%recycled/ 10%post-consumer paper

TO: PERMITS AND ENGINEERING UNIT
• WATER QUALITY SECTION
+ Attention: Dana Bolden
DATE: February 6, 1995
NPDES STAFF REPORT AND RECOMMENDATION
COUNTY Mitchell
PERMIT NUMBER NC0000353
PART I - GENERAL INFORMATION
1. Facility and Address: The Feldspar Corporation
Post Office Box 99
Spruce Pine, North Carolina 28777
2 . Date of Investigation: January 27, 1995
3 . Report Prepared By: Michael R. Parker
4. Persons Contacted and Telephone Number: Thomas Freeman
704/765-9051
5. Directions to Site: From the intersection of U.S. Highway 19E and .
NCSR 1121 in Spruce Pine, N.C. , travel east on NCSR 1121
approximately 0.4 mile. The Feldspar Corporation is located on
the right side of the highway and the wastewater treatment
facility is located behind the manufacturing plant near the river.
6 . Discharge Point(s) , List for all discharge points:
Latitude: 001 35° 54 ' 16" Longitude: 82° 03 ' 47"
002 35° 54 ' 17" 82° 03 ' 40"
003 35° 54 ' 17" 82° 03 ' 42"
Attach a USGS map extract and indicate treatment facility site and
discharge points on map.
U.S.G.S. Quad No. D10NE U.S.G.S. Quad Name Spruce Pine, N.C.
7. Size (land available for expansion and upgrading) : 1/2 acre
8 . Topography (relationship to flood plain included) : The wastewater
treatment facility is located approximately 40 feet above the
river and is not subject to flooding.
9. Location of nearest dwelling: Greater than 500 feet.
Page 1

10. Receiving stream or affected surface waters: North Toe River
a. Classification: C-trout
b. River Basin and Subbasin No. : 03 04 06
c. Describe receiving stream features and pertinent downstream
uses: fishing, wading, fish and wildlife propagation,
canoeing, industrial water supply, irrigation.
PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
1 . Type of wastewater: % Domestic
100 % Industrial
a. Volume of Wastewater: 3.5 MGD (Design Capacity)
b. Types and quantities of industrial wastewater:Wastewater is
from the processing of ore to produce Feldspar, mica, quartz
and sand.
c. Prevalent toxic constituents in wastewater: Fluoride.
d. Pretreatment Program (POTWs only) : NA
2. Production rates (industrial discharges only) in pounds per day:
a. Highest month in the past 12 months: 434.63 tons/day
b. Highest year in the past 5 years: lbs/day
3 . Description of industrial process (for industries only) and
applicable CFR Part and Subpart: The crushing of raw ore and
sending it through the various flotation processes for product
'separation. In accordance with 40 CFR Part 436 Subpart I-Mica and
Sericite Subcategory has been reserved and Subpart AI-Feldspar
Subcategory has also been reserved. No effluent guidelines have
been published.
4. Type of treatment (specify whether proposed or existing) : 001-The
existing wastewater treatment process consist of a 3 .5 MGD
inorganic solids wastewater treatment system with lime and acid
feed systems for pH adjustment, polymer feed systems, cyclone
separator, vacuum filters, three clarifiers, flow measuring and
totalizing equipment and recycle pumps. 002 & 003 non-contact
cooling water.
5. Sludge handling and disposal scheme: Sludge from the wastewater .
treatment facility is landfilled with approval of the Division of
Land Resources, Land Quality Section.
Page 2

•
6. Treatment plant classification (attach completed rating sheet) :
Class III.
• 7. SIC Codes (s) : 3295
Wastewater Code(s) : Primary 41 Secondary 14
Main Treatment Unit Code: 51002
PART III - OTHER PERTINENT INFORMATION
1. Is this facility being constructed with Construction Grant funds
(municipals only) ?
2. Special monitoring requests:
3 . Additional effluent limits requests:
4. Other:
PART IV - EVALUATION AND RECOMMENDATIONS
The Feldspar Corporation has requested modification of NPDES
Permit Number No. NC0000353 . The Feldspar and Unimin Corporation
have entered into an agreement in which The Feldspar Corporation
will give up 50 lbs of its current fluoride allocation and give
that allocation to Unimin Corporation for use at its Crystal
Operations. A copy of the agreement is attached to the report.
Two separate effluent limits pages should be included in The
Feldspar Corporation's permit. The first page should say "During
the period beginning on the effective date of this permit and
lasting until Unimin Corporation-Crystal Operations begin
discharging, " . The effluent limits should be as they now exist.
The second page should say "During the period beginning when
Unimin Corporation-Crystal Operations begin discharging and last
until expiration, " . The effluent limits on this page should be
modified with the fluoride reduced by 50 lbs monthly average and
100 lbs daily maximum.
Draft copies of the effluent pages are attached for your
information.
A copy of the letter requesting permit modification is also
attached to this staff report.
It is recommended that the permit be issued.
Page 3

5-0?4K:Aegt-e_ ;e7.,
Signature of Report reparer
Aer
ater Quality R gional Supervisor
4"/n°
" 737
Date
Page 4

,:,, Vsc� f;,s ANS
A. ().EFFLUENT LIMITATIONS AND MONITORING REQ 174NTS FINAL Permit No. NC0000353 ,
During the period beginning IA e..r IN;r'N-Coulrig 10Pr '" lasting until expiration,the Permittee is authorized to discharge from
outfall(s)serial number 001. Such discharges shall be limited and monitored by the permittee as specified below:
Effluent Characteristic. Discharge Limitation, Monitoring Requirements
Lbs/day Units (specify Measurement Sample •Sample
Mon. Avg, Daily May Mon. Avg. rally Max, Frequency LILLY Location
Flow 3.5 NICD Daily Continuous I or E
Settleable Solids Daily Grab E
Turbidity •• Daily Grab E,U,D M
Total Suspended Residue 1568.0 3137.0 Daily Composite E
Fluorides /7V.0 3g8.0 Daily Composite E,U,D
Chronic Toxicity*** Quarterly Composite E
*Sample locations:E-Effluent,U-Upstream at Station number 56,D-Downstream at Station number 59.
Daily stream sampling frequency may be reduced to three times per week. All stream samples may be grab samples.
**This discharge shall not increase the turbidity of the receiving stream more than 10 NTU. If the turbidity exceeds 10 NTU due to natural
conditions,the discharge shall not cause any increase in the turbidity.
*** Chronic Toxicity(Ceriodaphnia)P/F at 11%,January,April,July,October,See Part III,condition E.
The pH shall not be less than 6.0 standard units nor greater than 10.0 standard units and shall be monitored Daily at the effluent,Upstream and
Downstream by grab samples.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

A. ().EFFLUENT LIMITATIONS AND MONITORING REQUIREMETAL Permit No. NC0000353 ' ,
During the period beginning on the effective date of the permit and lasting until ,the Permittee is authorized to discharge from •
outfall(s)serial number 001. Such discharges shall be limited and monitored by the permittee as specified below:
Effluent Characteristic. Lbs/dav Discharge Limitations Monitoring Requirements
Units (specify Measurement Sample 'Sample
Mo-� Daily Max Mon. Avg. Dally Max, Freauency Tvoe Location
Flow 3.5 MGD Daily Continuous I or E
Settleable Solids Daily Grab E
Turbidity •• Daily Grab E,U,D ''1
Total Suspended Residue 1568.0 3137.0 Daily Composite E �J
Fluorides 224.0 448.0 Daily Composite E,U,D
Chronic Toxicity*** Quarterly Composite E
*Sample locations:E-Effluent,U-Upstream at Station number 56,D-Downstream at Station number 59.
Daily stream sampling frequency may be reduced to three times per week. All stream samples may be grab samples.
**'This discharge shall not increase the turbidity of the receiving stream more than 10 NTU. If the turbidity exceeds 10 NTU due to natural
conditions,the discharge shall not cause any increase in the turbidity.
*** Chronic Toxicity(Ceriodaphnia)P/F at 11%,January,April,July,October,See Part III,condition E.
The pH shall not be less than 6.0 standard units nor greater than 10.0 standard units and shall be monitored Daily at the effluent,Upstream and
Downstream by grab samples.
There shall be no discharge of floating solids or visible foam in other than trace amounts.
y
F1/ I i ,'fl
i

•
RATING SCALE FOR CLASSIFICATION OF WATER POLLUTION CONTROL SYSTEMS
Name of Facility: - 64/10- lt tad
Owner or Contact Person: i)L-' A/0/..../ -0'�
Mailing Address: e.0- ?bi[ 59 9Z€Lsa.t f /l.. NG 2777
County: fX El�14.V/ Telephone: 7051- 74 S-A2S-/
Present Classification: New Facility Existing Facility
NPDES Per. No. NCOO,203 3 Nondisc. Per. No.WQ Health Dept.Per No.
Rated by: /k ', L 1<< 'Z. ,Ait.,L..F. Telephone: 7u4//2,57-624e Date: x/6/45
Reviewed by: Health Dept. Telephone:
1r.f C. aiat4i. Regional Office Telephone: 7o%2.S/-4 tor
UU Central Office Telephone:
ORC:i wits aaa.,-.v Grade: _2L Telephoner'/,.r-9dS/
Check Classification(s): Subsurface Spra rrigation Land Applic tion
Wastewater Classification: (Circle One) I IIlier IV Total Points: 6 Ci
)µRANT PROCESSES AND RELATED CONTROL EOUIPMR4T WHICH ARE AN INTEGRAL PART OF INDUSTRIAL PRODUCTION SHALL Nr1T BE
CONSIDERED WASTE TREATMB1F FOR THE PURPOSE OF CLASSIFICATION.ALSO SEPTIC TANK SYSTBAS CONSISTING ON Y OF SEPTIC TAN(
AND GRAVITY NTTRIFICATIONIINES ARE EXEMPT FROM CLASSIFICATION,.
SUBSURFACECLASSIFICATION SPRAY IRRICiAT10N CIASSIFiCATION
(check all units that apply) (check all units that apply)
1. septic tanks 1. preliminary treatment (definition no. 32 )
2. pump tanks 2. lagoons
3, siphon or pump-dosing systems 3. septic tanks
4 sand filters 4. pump tanks
5. grease trap/interceptor 5. pumps
6, oiUwater separators 6sand filters
7. gravity subsurface treatment and disposal: 7, grease trap/interceptor
8. pressure subsurface treatment and disposal: 8. of/water separators
9_ disinfection
10. chemical addition for nutrient/algae control
11. spray irrigation of wastewater
In addition to the above classifications, pretreatment of wastewater In excess of these components shell
be rated using the point rating system and will require an operator with an appropriate dual certification.
LAND APPLICATION/RESIDUALS CLASSIFICATION(Applies only to permit holder)
1. Land application of biosotids, residuals or contaminated soils on a designated site.
WASTEWATER TREATMENT FACILITY CLASSIFICATION
The following systems shall be assigned a Class I classification,unless the flow is of a significant quantity or the technology is unusually
complex,to require consideration by the Commission on a case-by-case basis: (Check If Appropriate)
1. Oil/water Separator Systems consisting only of physical separation,pumps and disposal;
2. Septic Tank/Sand Filter Systems consisting only of septic tanks,dosing apparatus, pumps,sand filters, disinfection
and direct discharge;
3. Lagoon Systems consisting only of preliminary treatment,lagoons,pumps,disinfection, necessary chemical treatment for
algae or nutrient control, and direct discharge;
4. Closed-loop Recycle Systems;
5. Groundwater Remediation Systems consisting only of oit/water separators, pumps, air-stripping, carbon adsorption, disinfection
and disposal;
6. Aquaculture operations with discharge to surface waters;
7 Water Plant sludge handling and back-wash water treatment;
8. Seafood processing consisting of screening and disposal.
9. Single-family discharging systems,with the exception of Aerobic Treatment Units, will be classified if permitted after July 1,
1993 or if upon inspection by the Division,it is found that the system is not being adequately operated or maintained. Such
systems will be notified of the classification or reclassification by the Commission, in writing.

. • , The following scale is used for rating wastewater treatment facilities: (circle appropriate points)
REM POINTS
• (1) Industrial Pretreatmerx Units or Industrial Pratreatment Program(see definition No.33) 4
(2) DESIGN FLOW OF PLANT IN gpd[rot applicable to non-contaminated cooing waters.sludge handling facilities for
water purification plants,totally closed cycle systems(ses definition No.I I).and facilities consisting only of Item
(4)(d) or Items (4)(d) and (11)(d)) 1
0 - 20.000
20.001 - 50.000 .2
50.001 - 100,000 3
100.001 - 250.000 4
250,001 - 500.000 .5
500.001 - 1.000.000 .8
1,000,001 - 2.000.000 10
2.000.001 (and up)rate / point additional for each 200.000 gpd capacity up to a maximum of
��
Design Flow (gpd),of 000
(3) PRELIMINARY U ITS/PROCESS (see delNtion No.32)
(a) Bar Screens »- 1
or
(b) Mechanical Screens,Static Screens or Comminuting Devices......_......._„_...._ 2
(c) Gid Removal 1
or
(d) Mechanical or Aerated Ort Removal 2
(e) Flow Measuring Device 1
or CP
(f) Instrumented Flow Measurement.
Preaeration
(h) influent Flow Equalization.._ 2
(I) Grease or Oil Separators- Gravity......_..._ ». 2
Mechanical.............». ... .3
Dissolved Air Flotation...... .8
()) Prechlorkatlon .».» ,,. 5
(4) PRWARY TREATMENT U fTSIPROCESSES
(a) Septic Tank (see definition No. 43)....» ... 22
(b) Imhoff Tank
(c) Primary Clarillers.» ». 5
(d) Settling Ponds or Selling Tanks for inorganic Non-toxic Almada;(sludge handling facilities for water
purification plants,sand.gravel,store,and ether mining operations except recreational activities such as gem
orgold mining) 2
(5) SECONDARYTFiEA �
TMENT L �
(a) Carbonaceous Stage
(I) Aeration-High Pertly Oxygen System. 20
Diffused Ale System 10
Mechanical Ale System (fixed, floating or rotor)....._..._..._ .8
Separate Sludge Reaeration .3
(II) Tddding Filter
High Rate.... »»»» 7
Standard Rate ..... ... .5
Packed Tower ». .5
(III) Biological Aerated Filler or Aerated Biological Aker---...--...--...-----.....----1 0
(Iv) Aerated Lagoons ............. 10
(v) Rotating Biological Contactors ...... 10
(vi) Sand Filters -intermittent biological............. .».... . . 2
Recirculating biological »»» .3
(vi) Stabilization Lagoons». ..._..
Glenner...... ...
(Ix)) Single stage system for combined carbonaceous removal of BOO and nitrogenous removal by
rtitriticatlon(see definition No. 12XPol is for this item have to be in addition to Items
(5)(a)(I) through (5)(a)(vil1).
utilizing the extended aeration process(see defintlon No.3a) .2
utilizing other than the extended aeration process..... ....» 6
(x) Nutrient additions to enhance BOD removal 5
(xi) Biological Culture('Super Bugs')additlon 5
(b) Nitrogenous Stage
(I) Aeration High Purity Oxygen System._....__._.... .» »....».... ..........».... ....»..20
Mused Ale System.» ...„. 10
Mechanical Air System (fixed, floating or rotor) _ _.,. .8
(II) SeparateTrickling SFNaerer Reaendlon .37
Standard Rate..... .». .5
Packed Tower.._........_... . .5
Qg) Biological Aerated Filter or Aerated Biological Fliter.__..._.___..._.__..._._........__.__......_10
(Iv) Rotating Biological Contactors 10
(v) Sand Filter-fraemdment biological ... 2
Recirculating biological..... 3
(vI) Clarner.».......» .. .5
(6) TERTIARY ORADVANCEDTREA1MEt4RUVRSfpISSES
(a) Activated Carbon Beds
without carbon regeneration.... »....... 5
with carbon regeneration 15
(b) Powdered or Granular Activated Carbon Feed- •
without carbon regeneration .... .5
stripping with carbon regenenUon... ..... 15
(c) Ar ...._ .5
dDenitrlattbn Process ... .._ .» ..10
(e) Electrodialysis. » ..»....... ..» »......_.».. .5
(f) Foam Separation.- ».. 5
(g) Ion Exchange... ....»»._.....». »..».». .» .5
(h) Land Application of Treated Effluent(see definition No.22b)(not appicable for sand,gravel,stone
and other similar mining operations) by high rate kdttration.....»..._...._ _...»..._...»........_...._...„........_ 4
(I) Microscreons .s
(I) Phosphorous Removal by Biological Processes(See definition No.26) 20
(k) Polishing Ponds - without aeration. .2
with aeration........» »»..» .5

• (I) Post Aeration - cascade 0
- •
diffused or mechanical 2
(m) Reverse Osmosis .5
' (n) Sand or Mixed-Media Filters - low rate 2
high rate 5
(0) Treatment processes for removal of metal or cyanide 1 5
(p) treatment processes for removal of toxic materials other than metal or cyanide 1 5
(7) SL LICGE TREATMENT
(a) Sludge Digestion Tank - Heated (anaerobic) 10
Aerobic 5
Unheated(anaerobic) .3
(b) Sludge Stabilization(chemical or thermal) .5
(c) Sludge Drying Beds-Gravity 2
Vacuum Assisted .5
(d) Sludge Elutriation .5
(a) Sludge Conditioner (chemical or thermal) .5
(I) Sludge Thickener (gravity) .5
(g) Dissolved Air Flotation Unit(not applicable to a unit rated as (3)(i)] 8
(h) Sludge Gas Utilization (including gas storage) 2
(I) Sludge Holding Tank - Aerated .5
Non-aerated 2
(j) Sludge Incinerator(not Including activated carbon regeneration) 1
(k) Vacuum Filter,Centrifuge.or Filter Press or other similar dewatering devices - 1�['
(8) RESIDUALS UTILIZATION DISPOSAL(including incinerated ash)
2
(a) Laoons
b) Land Application(surface and subsurface)(see definition 22a)
by contracting to a land application operator or landfill operator who holds the land application permit
or Iandfil permit
(c) Dedicated Landllll(burial) by the permittee of the wastewater treatment facility 5
(9) t>rsi tIZN .5
(a) Chlorination
(b) Dechlorination 5
(c) Ozone .5
(d) Radiation .5
(10) CHEMICAL ADDITION SYSTEM(S)(see definition No.9)(not applicable to chemical additions rated as Item(3)(1).
(5)(a)(xi . (6)(a (6 ), b), (7)(e), (9a). (9)(b) or (9)(e) 5 points each:
a�atr 3
(11) MISCELLANEOUS U1TSIPROCF S
(a) Holding Ponds,Holding Tanks or Settling Ponds for Organic or Toxic Materials including wastes from mining
operations containing nitrogen or phosphorus compounds in amounts significantly greater than is common
for domestic wastewater .4
(b) Effluent Flow Equalization(not applicable to storage basins which are inherent In land application systems).....
(Scc) Stage Discharge(not applicable to storage basins inherertt in land application systems).....__.__.
d)
(0) Stand-By Power Supply .3
(() Thermal Pollution Control Devoe .3
TOTAL POINTS
CLASSIFICATION
Oats l 5-25 Points
Class II 26-50 Points
Class 11 51.65 Points .
Class)V 66-Up Points
Facilities having a rating of one through four points,Inclusive,do not require a certified operator.
Facilities having an activated sludge process will be assigned a minimum classification of Class I1.
Facilities having treatment processes for the removal of metal or cyanide will be assigned a minimum classification d Class II.
Facilities having tmatrners processes for the biological removal of phosphorus will be assigned a minimum classification of Class ill.
.0004 DEFNriIONS
The following definitions shall apply throughout this Subchapter.
(1)Activated Carbon Beds. A physkallchembal method for reducing soluble organic material from wastewater effluent;The column-type beds used In this
method will have a flow rate varying from two to eight gallons per minute per square loot and may be either upliow or dowmflow carbon beds. Carbon may or
may not be regenerated on the wastewater treatment plant site;
(2)Aerated Lagoons. A basin M which at solids are maintained In suspension and by which biological oxidation or organic matter is reduced through artificially
accelerated transfer of oxygen on a flow-though basis;
(3)Aeration. A process of bringing about Intimate contact between air or high purity oxygen In a liquid by spraying,agitation or diffusion;(3a) Extended
Aeration. An activated sludge process utilizing a minimum hydraulic detention time of 18 hours.
(4)Agriculturally managed site. Any site on which a crop Is produced,managed,and harvested(Crop Includes grasses,grains.tees,etc.);
(5)Air Stripping. A process by which the ammonium Ion Is first converted to dissolved ammonia(pH adjustment)with the ammonia then released to the
atmosphere by physical means;or other similar processes which remove petroleum products such as benzene.toluene,and xylene;
(6)Carbon Regeneration. The regeneration of exhausted carbon by the use of a furnace to provide extremely high temperatures which volatilize and oxidize the
absorbed impurities;
(7)Carbonaceous Stage. A stage of wastewater treatment designed to achieve'secondary'effluent limits;
(8)Centrifuge. A mechanical device In which centrifugal force is used to separate solids from liquids or to separate liquids of different dansi::aa'
(9)Chemical Addition Systems-The addition of chemical(s)to wastewater at an application polrtt for purposes d Improving solids removal,pH adjustment.
alkalinity control,etc.;the capability to experiment with afferent chemicals and afferent application points to achieve a specific result will be considered one
system;the capability to add chemical(s)to dual units will be rated u one system;capability to add a chemical at a different application points for different
purposes will result In the systems being rated as separate systems;
(10)Chemical Sludge Conditioning. The addition of a chemical compound such as lime,ferric chloride,or a polymer to wet sludge to Coalesce the mass prior to
its application to a dewatering device;
(11)Closed Cycle Systems. Use of holding ponds or holding tanks for containment of wastewater containing Inorganic,non-toxic materials from sand,gravel,
crushed stone or other similar operations.Such systems shall carry a maximum of two points regardless of pumping facilities or any other appurtenances;
(12)Combined Removal of Carbonaceous BOD and Nitrogenous Removal by Nhrificatbn-A single stage system required to achieve permit effluent limits on SOD
and ammonia nitrogen within the same biological reactor,
(13)Dechlorinatbn. The partial or complete reduction of residual chlorine in a liquid by any chemical or physical process;

(15)Electrodialysis. Process for removing Ionized salts from water through the use of ion-selective ion-exchange membranes;
(16)Filler Press. A process operated mechanically for partially dewatenng sludge;
(17) Foam Separation. The planned frothing of wastewater or wastewater effluent as a means of removing excessive amounts of detergent materials through
the introduction of air In the form of line bubbles;also called loam fractionation;
(18)Grit Removal. The process of removing grit and other heavy mineral matter from wastewater;
(19) Imhoff Tank. A deep two story wastewater tank consisting of an upper sedimentation chamber and a tower sludge digestion chamber.
(20)Instrumented Flow Measurement. A device which indicates and records rate of flow;
(21)Ion Exchange. A chemical process in which Ions from two different molecules are exchanged;
(22) Land application:
(a)Sludge Disposal. A final sludge disposal method by which wet sludge may be applied to land either by spraying on the surface or by subsurface injection
(i.e.,chisel plow);(not applicable for types of sludge described In(11)of this Rule];
(b)Treated Effluent. The process of spraying treated wastewater onto a land area or other methods of application of wastewater onto a land area as a
means of final disposal or treatment;
(23)Microscreen. A low speed,continuously back-washed, rotating drum lifter operating under gravity conditions as a polishing method for removing
suspended solids from effluent;
(24)Nitrification Process. The biochemical conversion of unoxidized nitrogen(ammonia and organic nitrogen)to oxidized nitrogen (usually nitrate);
(25)Nitrogenous Stage. A separate stage of wastewater treatment designed for the specific purpose of converting ammonia nitrogen to nitrate nitrogen;
(26) Phosphate Removal.Biological. The removal of phosphorus from wastewater by an oak/anoxic process designed to enhance luxury uptake of phosphorus
by the microorganisms;
(27) Polishing Pond. A holding pond following secondary treatment with sufficient detention time to allow settling of finely suspended solids;
(28) Post Aeration. Aeration following conventional secondary treatment units to Increase effluent D.O.or for any other purpose;
(29) Post Aeration. (Cascade) A polishing method by which dissolved oxygen is added to the effluent by a nonmechanical,gravity means of flowing down a
series of steps or weirs; The flow occurring across the steps or weirs moves in a fairly thin layer and the operation of the cascade requires no operator
adjustment;thus,zero points are assigned even though this Is an essential step to meeting the limits of the discharge permit;
(30)Powdered to Granular Activated Carbon Feed. A biophysical carbon process that utilizes biological activity and organic absorption by using powdered or
granular activated carbon; Virgin or regenerated carbon is feed controlled Into the system;
(31) Preaeratlon A tank constructed to provide aeration prior to primary treatment;
(32)Preliminary Units. Unit operations in the treatment process,such as screening and comminution,that prepare the liquor for subsequent major operations;
(33) Industrial Pretreatment.
(a)Pro-treatment Unit, Industrial. The conditioning of a waste at its source before discharge,to remove or to neutralize substances Injurious to sewers and
treatment processes or to effect a partial reduction in load on the treatment process which is operated by the same governing body as the wastewater
treatment plant being rated;
b)Pre-treatment Program,Industrial•must be a State or EPA required program to receive points on the rating sheet;
(34)Primary Clartliers. The first settling tanks through which wastewater is passed In a treatment works for the purpose of removing settleable and suspended
solids and BOD which is associated with the solids;
(35) Pumps. All influent, effluent and In-plant pumps;
(36)Radiation. Disinfection or sterilization process utilizing devices emitting ultraviolet or gamma rays;
(37)Reverse Osmosis. A treatment process In which a heavy contaminated liquid is pressurized through a membrane forming nearly pure liquid free from
suspended solids;
(38)Rotating Biological Contractors. A fixed biological growth process in which wastewater flows through tanks in which a series of partially submerged circular
surfaces are rotated;
(39)Sand Filters:
(a) Intermittent Biological. Filtration of effluent following septic tanks, lagoons,or some other treatment process In which further blodecamposition is
expected to produce desired effluents;Hydraulic loading rates on these filters are computed In gpd/ac end have a resulting low gprn/sf(less than one);
b)Recirculating biological-the same type of sand filter as defined in Subparagraph(39)(a)of this Rule with the added capability to recycle effluent back
through the sand filter,
(40)Sand or Mixed-Media Filters. A polishing process by which effluent limits are achieved through a further reduction of suspended solids;
(a)low rate—gravity,hydraulically loaded filter with loading rates in the one to three gpm/sl range;
(b)high rate—a pressure,hydraulically loaded fitter with loading rates in the five gpm/sf range;At any rate,the loading rate will exceed three gprwsf;
(41)Secondary Clarifiers. A tank which follows the biological unit of treatment plant and which has the purpose of removing sludges associated with the
biological treatment units;
(42)Separate Sludge Reaeration A pan of the contact stabilization process where the activated sludge is transferred to a tank and aerated before returning I
to the contact basin;
(43)Septic Tank A single—story settling tank In which settled sludge is In contact with the wastewater flowing through the tank;shall not be applicable for
septic tank systems serving single family residences having capacity of 2,000 gallons or less which discharge to a nitrflicatbn field;
(44)Sludge Digestion. The process by which organic or volatile matter and sludge is gasified,liquefied,mineralized or convened Into more stable organic matter
through the activity of IMrg organisms, which Includes aerated holding tanks;
(45)Sludge Drying Beds. An area comprising natural or artificial layers of porous materials upon which digested sewage sludge Is dried by drainage and
evaporation;
(46)Sludge Elutriation. A process of sludge conditioning in which certain constituents are removed by successive washings with fresh water or plant effluent;
(47)Sludge Gas Utilization. The process of using sewage gas for the purpose of heating buildings,driving erginfes,etc.;
(48)Sludge Holding Tank(Aerated and Nonaerated). A tank utilized for small wastewater treatment plants not containing a digester M which sludge may be
kept fresh,and supernatant withdrawn prior to a drying method(i.e.sludge drying beds);This may be done by adding a small amount of air simply to keep the
sludge fresh,but not necessarily an amount that would be required to achieve stabilization of organic matter. A nonaerated tank would simply be used to
decant sludge prior to dewatering and would not allow long periods (several days of detention) without resulting odor problems;
(49)Sludge incinerators. A furnace designed to bum sludge and to remove all moisture and combustible materials and reduce the sludge to a sterile ash;
(50)Sludge Stabilization(Chemical or Thermal). A process to make treated sludge less odorous and putrescble,and to reduce the pathogenic organism
content;This may be done by pH adjustment,chlorine dosing,or by heat treatment;
(51)Sludge Thickener. A type of sedimentation tank In which the sludge I permitted to settle and thicken through agitation and gravity;
(52)Stabilization Lagoon. A type of oxidation lagoon In which biological oxidation of organic matter Is effected by natural transfer of oxygen to the water from
air (not a polishing pond);
(53)Stand-By Power Supply. On site or portable electrical generating equipment;
(54)Static Screens. A stationary screen designed to remove solids,including non-biodegradable particulate(floatable solids,suspended solids and BOD
reduction)from municipal and industrial wastewater treatment systems;
(55)Tertiary Treatmentt. A stage of treatment following secondary which is primarily for the purpose of effluent polishing;A seating lagoon or sand or coal filter
might be employed for this purpose;
(56)Thermal Pollution Control Device. A device providing for the transfer of heat from a fluid flowing M tubes to another fluid outside the tubes,or vice versa;
or other means of regulating liquid temperatures;
(57)Thermal Sludge Conditioner. A conditioning process by which heat Is added for a protracted period of time to Improve the dewaterablllty of sludge by the
sollbilizing and hydraulizi g of the smaller and more highly hydrated sludge particles;
(58)Toxic Materials. Those wastes or combinations of wastes,including disease-causing agents which after discharge and upon exposure.Ingestion,Inhalation
or assimilation Into any organism,either directly from the environment or Indirectly by Ingestion though food chains,will cause death,disease,behavioral
abnormalities,cancer,genetic mutations,physiological malfunctions (including malfunctions In reproduction)or physical deformations,In such organisms or their
offspring;Toxic materials Include,by way of Illustration and not limitation:lead,cadmium,chromium, mercury,vanadium,arsenic,zinc,ortho-nitro-chlorobenzene
(ONCB),polychlorinated biphenyls(PCBs)and dkhlorodiphenyl trichloroethane(DDT);and any other materials that have or may hereafter be determined to have
toxic properties;
(59)Trickling Filter. A biological treatment unit consisting of a material such as broken stone or rock over which wastewater is distributed;A high rate trickling
filter is one which operated at between 10 and 30 mgd per acre. A low rate trickling filter is one which is designed to operate at one to lour mod per acre;
(60)Trickling Filter(Packed Tower). A plug flow type of operation In which wastewater flows down through successive layers of media or filtrate material;Organic
material Is removed continually by the active biological fixed growth In each successive layer. This method may produce'secondary'quality effluent,or may be
adapted to produce a nitrified effluent;
(61)Vacuum Filter,Centrifuges,or Filter Presses. Devices which are designed to remove excess water from either digested or undigested sludge prior to disposal
or further treatment.

.
- � r
THE /ds ar
CORPORAT/ON
A subsidiary of Corporation
Post Office Box 99, Spruce Pine, NC 28777
[phone] FAX: [phone]
December 12, 1994
Mr. Mike Parker
Division of Environmental Management
Water Quality Section
59 Woodfin Place
Asheville, North Carolina
Dear Mr. Parker:
As you are aware, Unimin Corporation purchased the Crystal Plant from The
Feldspar Corporation in 1991. The Feldspar Corporation has been treating the
effluent from that plant since that time. As pfied edimnnthe hesOperatingThe
Agreement between the two companies (copy enclosed) ,
Feldspar Corporation that it wishes to construct its own waste water treatment
facility. As part of the Operating Agreement, The Feldspar Corporation is
obligated to offer to have our existing NPDES Permit amended to reduce our
average daily pounds per day of fluorides allowance by 50 pounds and to reduce
our daily maximum pounds per day of fluorides allowance by 100 pounds in order
to facilitate Unimin obtaining the maximum fluoride discharge level which
Unimin is able to achieve in the permitting process.
The Feldspar Corporation wishes to honor this agreement by requesting permit
modification. This letter is intended to make the aforementioned offer for
the Crystal Plant only and is not for any other facility that Unimin currently
operates in this area. The Feldspar Corporation would expect to keep the
above mentioned allocation until such time that Unimin has completed the waste
treatment facility for the Crystal Plant. Once the Crystal Plant waste
treatment facility is complete, The Feldspar Corporation would no longer be
responsible in any way for the effluent from that facility. We will cooperate
with Unimin in every way during the transition period to protect the North Toe
River.
If you have any questions regarding this letter, please feel free to call me.
Thank you.
Sincerely yours,
THE FELDSPAR CORPORATION
( Pgjt&
John D. (Pete) Lawson
Vice President - Operations
JDL/h
Enclosure Cr '��y
cc: Charles Stover DEG r 3 1994

= +
(-
27.
27. Term. Unless terminated as otherwise provided
hereunder, this Agreement shall terminate on the date 99 years
after the date of this Agreement, and all the easements referred
- to in Section 12 hereof shall likewise terminate on said date.
28. Fluoride Allocation. If, after receiving notice
uN nnu,.: TPC
under Section 6 hereof or after Purchaser gives Operator notice
that it wishes to construct its own waste treatment facility and
terminate this Agreement following completion of such facility
and the attainment of its own waste discharge permits, or
otherwise, Purchaser applies to the Department of Environment,
Health and Natural Resources, State of North Carolina (or
successor or replacement agency) for an NPDES permit or other
appropriate permit to discharge effluent into the North Toe
River, Operator shall offer to appropriate governmental permit
authorities to have the Existing NPDES Permit or the New NPDES
Permit amended to reduce Operator's average daily pounds per day
of fluorides allowance by 50 pounds and to reduce Operator's
daily maximum pounds per day of fluorides allowance by 100 pounds
in order to facilitate Purchaser obtaining the maximum fluoride
discharge level which Purchaser is able to achieve in the
permitting process. If, at the time Purchaser applies for such
permit, the daily average pounds per day of fluorides permitted
A:\EXHIBIT8 - 35 -

.Y - • r
in the New NPDES Permit applicable to Operator shall be a number
other than 224 pounds, then the foregoing figure of 50 pounds
shall instead be 50 multiplied by a fraction of which the
numerator is the daily average pounds per day of fluoride then
permitted under Operator's New NPDES Permit and the denominator
of which is 224. If, at the time Purchaser applies for such
permit, the daily maximum pounds per day of fluorides permitted
in the New NPDES Permit applicable to Operator shall be a number
other than 448 pounds, then the foregoing figure of 100 pounds
shall instead of 100 multiplied by a fraction of which the
numerator is the daily maximum pounds per day of fluoride then
permitted under Operator's New NPDES Permit and the denominator
of which is 448 .
IN WITNESS WHEREOF, the parties hereto have executed
this Agreement under seal this _ day of , 1991 .
UNIMIN CORPORATION
1
By:
Title
ATTEST:
Title:
(Corporate Seal)
A:\EXHIBIT8 - 36 -

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