PB-239 566
STREAM POLLUTION ABATEMENT BY
SUPPLEMENTAL PUMPING
Carl W . Reh , e t a 1
Richmond City Department o' Public Utilities
\
1-••'"»'-'"*-•''"*"
Prepared fir:
National Environmental Research Center
February 1975
DISTRIBUTED BY:
Tc^ls&J tsferos^osi Sc-rtlse
U. S. SEP^TSQiT £-F CP^KEGCE
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//'/< Jfi n
VRINOn
I.PA-b70/2-?5-035 |
TECHNICAL REPORT DATA
traJ Inilfitt »<•»< f»i fn riim< him i.
J TltLt A\O SUUIITLE
"Stream Pollution Abatement by Supplemental Pumping"
PB 239 566
5 REPORT DATE
iL?'5-issuing Pat
6 PtRFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT r.O
Carl W. Rch and liarren IV. Sadler
9 PERFORMING ORC-MZATION NAME AN ADDRESS
City of Richmond, Virginia
Department of Public Utilities
Richmond, Virginia 25211)
10 PROr.RAM ELLMENT MO.
1HB054
11 Op^^A^.GRANT NO
11022 FLV
G ACC.MCV NAMfc AND AODRLSS
National Environmental Research Center
Office of Research and Development
U. S. T.nvironncntal Protection Agency
Cincinnati, Ohio 15268
13 TVPC OF RCPORT AND PERIOD COVCPEC
14 SPONSORING AGENCY CODE
15 SUPPLLVII ttTAHV NOTES
At the Riclimond, Virginia, h'astcuatcr Treatment Plant, a major structure,
i.e., a Supplenenta-1 Pumping Station, and «;c\er:il ancillary structures were
provided to achieve the project objective of no bypassing uhilc a ncv. grit
chamber was being connected ahead of the existing Main Pumping Station, which
station received and pumped all of the ran scha<-c. The Supplemental Pumping
Station uas constructed by sinking a tuo-comp.irtmcnt, sheet steel cofferdam
around an existing 72-inch concrete sewer and rearranging the* influent sewer
flon pattern so that the sewage uas redirected to the site of the Supplemental
Pumping Station. The redirection of scuagc tlow has achieved by the recon-
struction of a junction chamber and by the insertion of a specially designed
removable bulkhead, all without bypassing sewage. The time required for the
design, construction and operation of the Supplemental Pumping Station uas
about 36 months and the cost of this project uas approximately $900,000.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
hater quality
liastc treatment
I' IPENTIHCnS'OPEN tNOEO TCRMS
Richmond,(Virginia)
James River
Wastehatcr treatment
p 1 a n t
Supplemental pumping
On-line modification
Sheet s>recl coffercla
COSATI
15B
l~ri-llsut ION STATLMI.NT
Release lo Public
19 StCUKITY CLAbS (//IfI K,p,.rtl
Unclassi fied
21 NO Ul CAGES
20 SECURITY CLASS r'/iM/wcr;
Unclassified
32 PRICfc
EPA Form 2220 1 (9-73)
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0 6r:i?5
i:PA-670/2-75-035
1'cbruary 197S
STRLXM POLLUTION ABATEMENT
BY SUPPLEMENTAL PUMP IXC
By
Carl K. Reh and harren E. Sadler
City of Richmond, Virginia
Department of Public Utilities
Richmond, Virginia 23219
Grant Xo. 11022 FLV
Program Element 1BB05-J
Project Officer
R. F. Roudabush
U.S. Environmental Protection Agency
Region III
Philadelphia, Pennsylvania 19106
NATIONAL ENVIRONMENTAL RESI.ARCII CFNTPP
oi-ncr oi- RI:SI.ARCM AND DEVI.LOPMINT
•rl-Sivv-?"^"1^1' PROTICTIOX AGENCY
CINCIXNAII , OHIO 45268
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REVIEW XOTICr.
The National Envi ronmcnta 1 Rcscarcli Center--
Cincinnati has revicued this report and approved
its publication. Approval does not signify that
the contents necessarily reflect tl : vicus and
policies of the U. S. Environmental Protection
Agency, nor docs mention of tiade names or com-
mercial p.oducts constitute endorsement or recom-
mendation for use.
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JOR I: t 0 RI)
Man and his environment must be protected from the
adverse effects of pesticides, radiation, noise and other
forms of pollution, and the un ise management of solid
waste. Efforts to protect the environment require a
focus that recogni :Cs the in terplay het ecn the com-
ponents of our physic:il envi roninent——air, t%atcr, and
land. The National Invirotimental Research Centers
provide this niultid.’ciplinary focus through programs
engaged in
• studies on the effects of environmental
contaminants on man and the 1)1 osphe re , and
o a search foi h3 S to prevent contamina-
tion and to recycle valuable resources.
This report describes the construction and operation
of a Supp]ementa 1 I’unipi ng Station that as insrzi lIed at
the Ri chnond { i rg in la) hastc atcr Treatment Plant . The
use of this station made it possible to continue plant
operation hi]e net plant units ;ere being installed.
A. h. Rreidenbach, Ph.D.
Director
National Fnvironmcntal
Research Center, Cincinnati
‘ i i
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ABSTRACT
In past times, the insertion of a major element into
an existing sewage treatment plant was accomplished by
taking the plant out of service and bypassing sewage during
the cut-in period. It is possible to insert, new plant units
in major sewage treatment works without bypassing; however,
avoidance of bypassing may require the construction of other
major facilities.
At the Richrbond, Virginia Wastewater Treatment Plant,
(Annual Average Capacity = 70 mgd) a major structure, i. e.,
a Supplemental Pumping Station, and several ancillary struc-
tures were provided to achieve the project objective of no
bypassing w1’ile a new grit chamber was being connected
ahead of the existing Main Pumping Stition, t hich station
received and pumped all of the raw sewage.
The Supplemental Pumping Station was constructed by
sinking a two—compartment, sheet steel cofferdam around an
existing 72-inch concrete sewer and rearranging the influ-
ent sewer flow pattern so that the sewage was redirected
to th site of the Supplemental Pumping Station. The re-
direction of sewage flow was achieved by the reconstruction
of a junction chamber and by the insertion of a specially
designed rem wable bulkhead, ;ill without bypassing sewage.
The time required for the design, construction and
operation of the Supplemental Pumping Station was about 36
iv
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months. The cost of dcsign, construct.A..- and operation was
about $900,000.00, of which $282,022.00 was provided by a
E1’A Demonstration Grant.
This report is submitted in fulfillment of Research,
Development and Demonstration Grant 11O22FLV, Construction
Grants 1 1PC—VA-246 and WPC-VA—273 from the Environmental
Protection Ayency to the City of Richmond, Virginia.
V
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CONTENTS
Page
Abstract iv
List of Figures vii
List of Tables x
Acknowledgments xi
Secticns
I Conclusions i
II Recommendations 3
iii: Introduction 6
IV The Construction Design 30
V The Construction 62
VI The Operations 74
VII Discussion 87
VIII References 107
‘Ti
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FIGURES
No. Page
1 General Location Map. . 7
2 Grit Removal Facilities
View of New Grit Removal Facilities 8
3 Grit Removal Facilities
View of Open Channels of the Grit Chamber • 9
4 Tributary Intercepting System and Treatment
Plant Facilities 12—13
5 Existing Conditions Prior to Construction of
Grit Removal Facilities 14—15
6 Flow Diagram
Temporary Bypassing with Chlorination 16
7 Flow Diagram
Alt. 3 with Supplemental Pumping Station. . . .
8 Work Done Under Alternate B to Avoid 3ypassing. . 20-21
9 Hydraulic Profiles 2 -23
10 South Junction Chamber
Temporary Bulkhead. . . . . . . . . . . • • . • 26-27
11 Plan and Section 32-33
12 Sectio’ 343
13 Supplemental Pumping Station
Grading for Site . . . . . • 36
14 Supplemental Pumping Station
Erecting Working Platforri • . . . . • . 37
15 Supplemental Pumping Station
Driving Sheet Steel Piling Cofferdam for
Substructure . • . . . • • . 38
16 Supplemental Pumping Station
Cross Lot Bracing of Substructure . . . . • . • 39
17 Supplemental Pumping Station
Existing 72-Inch Lower Goodes Creek
Intercepting Sewer • • . . • . • . 40
vii
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FIGURES (Continued)
No. Page
18 SupplementaL Pumping Station
Partially Completed Pumping Station,
Discharge Piping and Diversion Structure. . . . 41
19 Supplemental Pumping Station
Interior View of Sewagt Pumping Units . . . . . 42
20 Supplemental Pumping Station
Exterior View of Completed Pumping
Station and Discharge Piping 43
21 Supplemental Pumping Station
Pun ping Station Discharge Piping and
Diversion Chamber . . . . . . . . . . . . . . . 44
22 Supplemental Pumping Station
View of Open Wet Well and Enclosed
PumpRoorn. . . . .45
23 Diversion Structure
Breaking Out Openings for Discharge Pipe
and Temporary Bulkhead. . . . . . . . . . . . . 46
24 Supplemental Pumping Station
Electrical — One Line Diagram . . . . . . . . . 50-51
25 South Junction Chamber
Transporting Prefabricated Special
Bulkhead to Site . 55
26 South Junction Chamber
Lowering Bulkhead into Place . 56
27 South Junction Chamber
Scuth Face of Chamber Showing Bulkhead
in Place. . . . . 57
28 South Junction Chamber
Preparation for Construction of
New Junction Chamber . . . . . . . . 58
29 South Junction Chamber
Placing Reinforcing Steel for Conduit
Between New Junction Chamber and
Inlet Chamber . . . . . . . . . . . . . . . . . 59
vii i
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FIGURES (Continued)
No. Page
30 South Junction Chamber
Removal of Prefabricated Bulkhead 60
31 Chronology 72-7"
32 Sewage Pumping Units
Characteristic Curves 80-31
33 Calibration Curve
Plant Effluent Weir vs Supplemental
Pumping Station Flow 82
34 Wastewater Treatment Plant
Plant Effluent Flow 84-8*
35 River Sampling Stations 88
36 James River, Dissolved Oxygen Level 91
37 James River, Biochemical Oxygen Demand 92
38 Wastewater Treatment Plant
Influent and Effluent Loadings
Suspended Solids 9fi-97
39 Wastewater Treatment Plant
Influent and Effluent Loadings
Biochemical Oxygen Demand 98-99
ix
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TABLES
Page
No. - *—
1 Monthly Flow Summary .............. 86
2 River Sampling Data
July, 1963-Junc, 1969
4
River Sampling Data
February, 1972-Derember, 1972 90
Treatment Plant Loadings 93
5 James River Flow
January, 1958-December, 1972 100
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Acknow ledge’ ’e nts
This project was financially supported by the City of
Richmond, Virginia, and by grants from the Environmental
Protection Agency.
Messrs. Harold J. Snyder, Jr. and Fenton Roudabush
were the Project Officers for the Office of Water Programs
of the Environmental Protection Agency. Mr. Snyder was in—
struinental in assisting the City in securing the Research
and Demonstraion Grant and Mr. Roudabush was most cooper-
ative in assi5ting the City with the administration of this
project.
Staff personnel of both the Department of Health and
the Water Control Board of the Commonwealth of Virginia
were most helpful during the entire period that this Re-
search and Demonstration Project was conducted.
We wish to extend our sincere appreciation to both
Contractors who worked on the project; Potter and Parsons,
Inc., Baltimore, Maryland, who furnished the pumping equip-
ment and the English Construction Company, Inc., Altavista,
Virginia, who constr”cted the Supplemental. Pumping Station
and installed the equipment. The English Construction Com-
pany also constructed all the other appurtenant work necessary
to make connections between existing facilities and the net’
Grit Chamber and also between the existing primary treatment
plant and secondary treatment works.
xi
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Grecley and Hansen of Chicago, Illinois, were the
Consulting Engineers responsible for the design of the
Research ard Demonstration project and assisted in the
supervision of th construction of these facilities.
The project was under the direction of Mr. H. E.
Lordley, Director of the Department of PubliC Utilities
of the City of Richmond, who was abJy assisted by Mr.
G. M. De’ano, Chief, Utility Plants, and Mr. L. H. Roden,
3r., Chief, Division of Wastewater Treatment. Mr. Roden
was the City’s Project Coordinator for this project.
xii
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SECTION I
CON CLUS I ONS
1. The project demonstrates that it is possible to cut in
a major sewage treatment plant element without the need
for bypassing raw sewage.
2. W ere no special provisions have been made either in
the existing works or in the design of the new facili-
ties for cutting ¶.n major plant ements without by-
passing, special design will be required to achieve the
“no bypassing” objective. In the case of this project,
the special design required principally the supplemental
pumping station and the construction of a unique bulk-
head with a built-in sluice gate.
3. “umping units of standard design can be used. The
pumping units which were selected were variable speed
motor driven vertical centr fugal pumps.
4. A two compartment sheet steel cofferdam is a feasible
means for constructing a pumping station substructure
around an existing sewer.
5. The time for design and construction of so-called temp-
orary facilities is likely to approach that required
for conventional facilities.
6. fleliable operation can be achieved through the design
of simple mechanical configurations. Thr total control
was: ?ump-on, pump-off. and pump-speech Suction or
discharge valves were not operated as a part of the
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start-stop sequence.
7. Variable speed pump operation is feasible without a
wet well. The close control of pumping levels, however,
is difficult to achieve and requires more than ordinary
attention.
8. Provisions should be included for large debris from
finding its way into the pump suction through unantic-
ipated water levels. Large garbage cans and tires suc-
ceeded in finding their way behind the coarse bar racks
and interfered briefly with pumping operations.
9. The degree of treatment of sewage was maintained through-
out the construction period.
10. o deterioration in th water cuality in the James
River was experienced throughout the construction
period.
11. The scheduled bypassing time for the construction of
the grit chamber was 110 calendar days. The time re-
quired to design, construct and operate the supple-
mental pumping station was 36 months. The total sewage
pumped was 13,125 mg.
12. The ccst of the new grit chamber was approximately $1.8
million. The cost of the supplemental pumping station
and appurtenant work was $900,000. This amount in-
cluded the cost of design, construction and operation.
If all costs of the supplemental pumping station are
applied to the cost of pumping sewage 1 the amount would
be $65.! 4 per million gallons.
2
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SECTION XI
RECOMMENDATIONS
1. This demonstration was necessary because of a change
in Federal guidelines. At the time a new grit chamber
was scheduled to be connected to the sewage treatment
works, the Federal guidelines were revised to prohibit
any bypassing of raw sewage to receiving waterways
As a result, the use of the new grit chamber was
delayed about 36 months until a suppleme-rtary pumping
station could be designed and constructed and the
necessary connecting works completed. It .is recom-
mended, therefore, that, to the maxii ’um extent possible,
any project approved under one set of gtidelines, and
for which the major construction has been accomplished,
be allowed to be completed under those guidelines
rather than be conformed to a new set of criteria.
2. The project demonstrated that new plant facilities can
be cut into an existing plant without the need for
bypassiriçj. The delays in the completion of the new
works cemonstrated the need to include those facilitics
for the avoidance of bypassing among the provisions
for cut-in included as part of the original design.
Such facilities should not be made a separate element
of work.
3
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3. If supplemental pumping is required, the facilities
for such supplemental pumping should be included as
a part of the general plant construction. A greater
selection of pumping equipment will thereby be made
available and the time for construction and for
pumping will be coincident with the general plant
construction and will not be made a sequential itei
of work. The cost for such supplemental facilities
will be reduced by this procedure.
4. Pump control is basic to the operation of the
supplemental pumping station. Usual automatic
controls are not adeauate for a pumping facility
which has no wet well. It is necessary that a single
level he defined for the control of all pumps at all
speeds. Such a set point controller will facilitate
automatic operation and will avoid problems in ump
speed setting.
5. If a supp emental pumping statirn is to be strictly
a one-time temporary pumping station, simpler config-
urations for the substructure should be explored to
reduce both the tine and the cost. Multiple smaller
circular cofferc]ams may be feasible and if the time
for the exploration of pump types is available, some
form of a vertical wet pit type dredge pump might be
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suspended within the cofferdam. These elements
may tend to reduce time and cost.
6. The supplemental pumpinq station was planned to
function about 110 days whi’e the new grit char ber
was being cut into the system. It was to be main-
tained on a standby basis should some future contin-
gency require its reactivation. If a supplemental
or a standby pumping tation is to be maintained for
the total life of the treatment works, the substruc-
ture should be large enough to accommodate equipment
for all the future sewage quantities to be expected.
The design concept r ight be different from the one
which has been constructed. The function of a proposed
supplemental pumping station shculd be fully explored
and developed prior to the start of design.
S
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SECTION III
INTRODUCTION
A. The Problem
The Richmond Sewage Treatment Plant was designed during
the early l9SO’s and placed in operation in 1958. ost
p1 ints of this age had no means of routing sewage around its
main pumping station without bypassing raw sewage. The
practice of bypassing has always been permitted in th? past
throughout the country.
The City of Richmo’ d is engaged in making certain ad-
ditions to, and improvements in, its sewage treatment works.
rigure 1 shows the relationship of the Wastewater Treatment
Plant to the City of Richmond. Specifically, a new grit re-
moval chamber now completed had to be connected to the plant’s
main pumping station wtiich lifts all sewage into the plant.
The grit removal charther was constructed at a cost of $1.3
million, including a 30 percent EPA grant. Photographs of
the new Grit Facilities are shown in Figur 2 and 3. The
City also has secondary treatment facilities under construc-
tion which had to be connected to the present primary treat-
ment plant at several locations. These secondary treatment
facilities had also been approved for EPA grant participation.
In addition, due to the severe flood in August, 1969, which
inundated much of the treatment works, certain cleaning and
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ii
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Figure 1
General Location Ma
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Figure 2
Grit Removal Facilities
View of New Grit Removal Facilities
A
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Figure 3
Grit Peroval Facilities
View of C’pen Channels of thi (rit Charnher
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maintenance operations had to be performed.
The grit chamber was projected to be completed by
November 1, 1969, irtd it was planned to cut in the new
facilities during a 110—day period beginning on that date.
During this 110-day period, the normal dry weather sewage
flow of approximately 30 million gallons per day would be
chlorinated and discharged directly into the James River,
thereby bypassing the plant. The Virginia Water Control
Board had approved the proposed plan. Prior approval had
also been obtained from the IJ.S. t:nvironrnetital I’rotection
Agency in 1967 as part of its review of the City’s plans
for the construction of the grit removal facility and the
initiation of construction of the secondary treatment works.
The Regional Director of the Federal Water Pollution
Control Agency announced in September, 1969, that his Agency
was opposed to the bypass. lie stated that he would initiate
action to prohibit the City from bypassing sewage into the
James River and would oppose further Federal funding of
i ichrnond’s sewage treatment works if this were done.
This new public policy prohibiting plant shutdown and
bypassing provided a complete departure frcm the procedure
previously approved by the Regulatory Agencies, and created
a new problem for the City in that no provision had been
made in the design for the connection of the new plant
elements without a plant shutdown. The City accepted the
new policy and directed its engineers, Greeley and Hansen,
to dcve3 p schemes whereby the necessary work could be
10
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accomplished without bypassing sewage into the James River.
13. The System
Figure 1 shows a general location map of the Richmond
area. Figure 4 shows the major sewers entering the Waste-
water Treatment Plant. rigure 5 shows the arrangement of
the sewers and plant structures in the vicinity of the l ain
Pumping Station prior to tl.e construction of the new g..it
removal facilities. Figure 6 illustrateF a flow diagram to
accomplish temporary bypassing of plant facilities during
the construction of the connecting conduits for the new
grit chambers.
Two alter atjve methods were devised which would permit
the connection of the new grit removal facilities without
plant shutdown and without bypassing the raw sewage into
the James River.
1. Alternate A comprised the installation of a
60-inch temporary bypass around the inlet conduit
to the pumping station from the new diversion
chamber to the inlet of the Main Pumping Station.
A temporary bulkhead would be required to be in-
stalled at the outlet of the south junction
chamber. Temporary bulkheads were also required
at the entrance to the Main Pumping Station. If
this arrangement could be provided, the plant
could be kept in operation, using the existing
Main Pumping St .ion, while the new grit ::emova].
, 11
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/ A
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(flo wkr
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$LII,ICNlP ’\
100 0 tOO 400
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DIVISION £
4
SEWER
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DIVISION A
LOCK kIVER CROSSING
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DIVISION B
CREEK INTERCEPTING
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SEWER
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DIVISION C
HULL ST’FT N T(RCEPTING SEWE
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DIV ION Z PART I
G000ES CREEK TERCEPTING SEWER 1.
ii
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Sludqe ôsds
- ______
TURNPIKE
___-- —.------—-.
FIGURE 4
TRIBUTARY INTERCEPTING YSTEM
AND
TREATMENT PLANT FACILITIES
13
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7,
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DIVISION - A
LOCK RIVER CROSSING
/
‘ -
‘ .‘GORDON AVENUE
COMBINED SEWER
CHLORIt
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DIVISION C
L STREET INTERCEPTING SEWER
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14
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DIVISsON Z PART I
LOWEft 000DES CREEK INTERCEPTING SEWER - -
--——-----—-—----——----———
: 5 10N S T RUC T URET::::
SCREEN AND GRIT BUILDING
umet P*!11 N STAT$O
FIGURE 5
EXISTING CONDITIONS PRIOR TO
CONSTRUCTION OF
GRIT REMOVAL FACILITIES
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15
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FiGURE 6
FLOW DIAGRAM
TEMPORARY BYPASSING WITH CHLORINATIOt
16
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chamber was connected to the plant.
2. Alternate B visualized the construction of a
Supplemental Pumping Station. Sewage could be
diverted to the Supplemental Pumping Station by
reversing the flow through the 72-inch Lower
Goodes Creek Intercepting Sewer which ultimately
would carry sewage to a junction chamber adjacer.t
to th. Main Pumping Station, and thereby divert
the sewage around the main pumping station and
force main to the treatment facilities. A temp-
orary bulkhead would be required to be installed
at the outlet of the south junction chamber and
in the diversion chamber where the new supple-
mental pumps would discharge. This would permit
the new grit removal chamber to be connected and
the cleaning and maintenance of the Main Pumping
Station and force main to take place without the
necessity of bypassing ur.treated seuage into the
James River.
A Supplemental Pumping Station could solve the
immediate problem, and could be used in the future
should an emergency arise requiring a shutdown of
the Main Pumping Station and force main.
The arrangement for a Supplemental Pumping Station
and ancillary facilities is shown on Figure 7.
17
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4
FIGURE 7
FLOW DIAGRAM
ALT. B WITH SUPPLEMENTAL PUMPING STA.
RIVER CROSSING
LJAM(5 RIVER
HULL STREET
INTERCEPTING
GORDON AVENUE
COMBINED SEWER
‘p . ’,
St e ‘s-
GORDON AVENUE
OVERFLOW REL F
CHAMBER
GORDON AVENUE
COMBINED SEWER
p 1 ., 4’
Sri, -
LOWER G000ES CREEK
INTERCEPTING SEWER
MAIN PU*(JPING STATION
GORDON AVENUE
INTERCEPT ING
CHAMBER
GORDON AVENUE
COMBINED SEWER- -
T PIQ,?f
PUMPING
STATION
18
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C. Physical Requirements for Constructing Supplemental
Pumping Station
1. Location of Supplemental Pumpinq Station
The preferred location of the Supplemental
Pumping Station on the Lower Goodes Creek Inter-
cepting Sewer was such that the pumping station would
not be excessively deep, the water levels in the wet
well would not be too high so as to surcharge the
sewers and cause overflow into the James River, and
that relatively inexpensive modifications would be
required to the existing structures.
As shown on Figure 8, a suitable location for
the Supplemental Pumping Station would be close to
the existina 96-inch force main. Figure 9 shows the
hydraulic profiles extending from the river crossing
through the Lower Goodes Creek Intercepting Sewer,
through the Supplemental Pumping Station and to the
diversion structure. The profile also shows the con-
nection from the south junction chamber through the
new Grit Chamber to the Main Pumping Station. The
flow from the pumping station would be discharged to
the existing diversion chamber at which point pre—
chlorination normally occurs.
The location had to be such that at any’ time in
the future should it become necessary to provide ad-
ditional pumping capacity at the Main Pumping Station
19
-------
d V
— —I •
_ __— Z
__ ;— ,--.—
- ‘ J --
DVERS ON CHAP 3EN AND OYPASS L1? E I’
C.nsfr. cl.d tO r*rf F/ow tr m S vM .A,nc , Chombir ffvowgh I * I
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20
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SOV1N JUP CTIt
Spctt l Ad inoo’ h?s omd u i tlfoaI ov Vl in ?1ra i ,, ivvi ro
Me S/u/ion
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ADDITIONAL WORK UND DIVISIONS X , XII AND XIII
A. Main Pumping Stotios - moo’, /,Ce /,on /0 mel we/I
S. Fa c• Main — c/coning ol 96-,Ach ore• main.
0
-------
SIWPLEMCNTA4. PUMPING STATION 1
R se g. d,,rled Lippimerdol Pvmpin9 Stof,o. ty r .e,swç . P2-mic*
‘Qvsfr se.’ea Iherefo’ permimn Me new Gril Chamber 1 01 conr,C 1d ood
be dose a, Mo 4 rn Aimpsn Sloho , and force meet wiVhc.d b poua ,c
w rso *d Se.09 10 M i .b’we River
1 w SLUICE GATE CHANGER
I .‘ms go * s of Me flOw Gil fOciblies, Mo ,, Ptiwpw ,q Stohon end force mem
IL o r necessofy inomiene e or eipons,o, ork
- -
-
—
—
, -
7
(n
FIGURE 8
WORK DONE UNDER
ALTERNATE B
TO AVOID BYPASSING
-
I DIVERSION CHAM3ER
Modd d oeccirimodaf thscho,qs frøm S pbmeMolRarp$g loe’
Lend a convey f/ar ic lb. nt o, irsoimeni.
I
5 Crie17I I 3rif &iii.v’.g-’
‘ ¼
t
‘p
PLAPITCOP IECTIOP4S FOM SECO WARY T ATt? HT FACILITr S
During lbs rrg of Me &&rpplemonic( Pumping $,. ,, Ibe f / .o p nr i g were
mode Fe Secon#.v; rr,o ir,.nl fec ’ mg aic’ido P/oaF sftyldo.rn end typos row
uwoge 10 Me domes River
(a) Conneclios bi/ween me mflv#sf cf.en,eF ond be Pr.hM ery Se iwenFolio. TonOs.
(1) Ce nec/ian t1w•ei , fl affluent of lh P ,Mw4 Se#i ealefim Ten*so
Seccndery Treolment Focs/n’ni.
(ci Co ’nscF ,Os a, CAiffo// Chon,ber flo. 3.op•i W a ,ifo 7 i rs ! , , for Me
pr ii , ,Or, - seconday Freolm af woOs.
} ‘ I
I I
4J’v’r; 15 f,a lion 8g .i
I,
II
I Iii’r’i/’’ , .,“
21
-------
eti • O vrf,o,. QsI,gf CA.,r ep
ki
l ii
a —
‘ii
_______—__________
7 7 P7? - -
,-5ez // “arnter Ajenue Co ’r&ôir,ed.5ewer
Z )
Lor e- Ge cdes C e1c /P #ercepteng 3e er-
________ (72PC.PSe*er)
-J
PROFILE
FROM SOUTH JUNCTION CHAMB(R TO D:VERSION CHAMBER
PROFILE
FROM SOUTH JUNCTION CHAI(R TO MANS PU eSIG STATIOM
22
40
30
20
tO
44
‘4
0
-w
-20
-
40
30
20
(0
-4
‘4
-I0
-20
-50
-40
-------
I,
0
SOuTs JJP4(TION MA JB(R TO D v(RSION CHAMB(R
‘00 rt
____ I..s0•
FIGURE 9
HYDRAULIC PROFILES
5u cpIemenFa.’ Pu v p 9 ,5I’jI’, n
I
40
30
20
I-
1
0
PROF ILE
23
-------
or make any repairs to equipment, all of which would
require a shutdown, the Supplemental Pumping Station
could be reactivated thereby permitting continuous
operations without bypassing to the James River.
2. Gordon Avenue Overflow Relief Chamber
Prior to the directive from the Federal Water
Pollution Control Agency to accomplish the plant im-
provements without bypassing, the Gordon Avenue Over-
f low Relief Chamber was designed to take the flow from
the Lower Goodes Creek Intercepting Sewer and also to
serve as the point of chlorination of all the sewage
bcing bypassed to the James River. with the construction
of the Supplemental Pumping Station, this structure no
longer serves any purpose.
3. Plant Connections for Secondary Treatment
Facilities
Connections of the secondary treatment facilities
which were originally planned to be made during the
110 days of plant shutdown were redesigned, based on
the new concept of the Federal Water Pollution Control
Administration that no bypassing to the river is per-
mitted. The three connections which were made while
the plant was kept in operation are as follows:
(a) Connection between the infiuent channel
and the preliminary sedimentation tanks.
24
-------
(b) Connection between the effluent of the
preliminary sedimentation tanks and the
secondary treatment facilities.
Cc) Connection at Outfall Chan’ber No. 3,
which is part of the outfall system for
the primary-secondary treatment works.
4. Bulkheading the Inlet to the Main PuTTiping
Station
Figure 10 shows the existing south junction chamber
and the temporary bulkhead which must be installed in
the 8—foot square outlet. This bulkhead must be in-
stalled in this junction chair ber to divert the flow to
the Supplemental Pumping Station. 3-foot by 4-foot
sluice gate was installed on the bulkhead to permit its
installation.
B. The Design Problem
The average tributary dry weather flow to the
Wastewater Treatment Plant is approximate]y 30 mgd with
minimum flows in the range of 15 to 17 mgd and maximum
dry weather flows approximating 50 mgd. In the design
of the Supplemental Pumping Station, it as planned to
provide two or three pumping units with an installed
capacity ranging between 90 and 100 mgd. Therefore,
operating these units simultaneously, capacity would
be available for approximately three times the average
25
-------
PLAN
. h iit ,o:ke
A: Sea ”,
A
C,Fy Lock P , ,Cr.si ’g
(ôô o ACP)
: “ jj P’:•
A’S.’; - ;S
SECTION A-A
A
_ ‘ , Co:’ P•,. -
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R ,:.,.#.‘ ‘,.:,..r.i5eAs_
: .,
5 ,,,1 Q&i’i
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b’ o RCP, ’
(44 ’ ., , Pumping 5I 9,o,,
-- -
26
ca t
4 5 5 .—
-------
A SUGCEST(O SEOIJENCF OF ROU TO BE PERFORMED
INSTILLATION OF BUUI4!AI STRUCTURE
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FIGURE 10
SOUTH JUNCTION CHAMBER
TEMPORARY BULKHEAD
27
-------
dry weather flow or twice the maximum dry weather flow.
In addition,the outlet from each pump was designed
with a siphon to prevent backf low from the point of
discharge (existing diversion chamber) while the Main
Pumping Station is in operation and the Supplemental
Pumping Station is in a standby condition.
In considering the above,it :as important to find
equipr tent which was readily available and easily in-
stalled.
The various motive powers considered to drive the
pumps were gas engines, diesel engines and electric
motors.
Sludge gas or natural gas were not available at
the plant site during the time of design or construction.
Therefore, gas engine drives were not considered.
Diesel engines would be required to operate for
extended periods of time at very slow speeds due to the
minimum sewage flows which could be encountered at the
pumping station. This type of operation, with economical
high speed enqines, would require excessive maintenance
to keep the injectors and the ports clean; thus the re-
liability of the station would be reduced. Therefore,
diesel engine drives were not used.
Electric motors require a minimL.m amount of main-
tenance with very good reliabilicy. In addition, re-
liable power was available a short distance from the
28
-------
Supplemental Pumping Station. Therefore, variable
speed electric motors were selected as the pump drives.
The control of the pump speed is important so that
the wet well will not rise to such a level that the
sewers surcharge and discharge raw sewage into the James
River. The depth of the pumping station was set so that
the pumps would not operate dry at minimum ‘ peed when
the level in the wet well was at a minimum.
The bulkhead required to be installed in the existing
south junction chamber presented a difficult problem.
Although this was the best possible location for the
bulkhead, no standard device would work, including in-
flatable plugs, flat plates, stop logs, etc. Whatever
type of bulkhead was to be used would rc quire instal-
lation while the sewage was flowing through the existing
structure. The structure, however, r:as not designed
for the head which would be imposed on it with the in-
stallation of a bulkhead.
An involved and costly procedure was necessary to
solve this problem.
29
-------
SECTION IV
ThE CONSTRUCTION DESIGN
A. Descripticn of the Pumping Station Design
1. Structural : The supplemental pumping station was
to be designed as a simple economical structure con-
sisting of a sheet steel piling cofferdam to be built
around the existing 72-inch ID Lower Goodes Creek
Intercepting Sewer and to act as the substructure for
the pumping station. A dividing wall of sheet steel
piling set on a short concrete wall divides the sub-
structure into the wet well and the pump room in the
dry well. The scheme of sheeting was with wales and
cross-lot bracing located ir, such a manner as to form
a structurally sound substructure and to permit reason-
able location of the required equipment. The design
was such that the shceting was to be driven to rock
and then the concrete base placed and keyed into the
rock.
The loads for a structure as deep as this were
very substantial necessitating very large walers and
struts. After the structure was completed, the upper
portion of the existing 72-inch reinforced concrete
Lower Goodes Creek Intercepting Sewer pipe was removed,
thus forming part of the wet well. Figures 11 and 12
illustrate the type of construction.
30
-------
Figures 13 to 23, inclusive, illustrate a general
sequence of construction of the Supplemental Pumping
Station and the modifications to the diversion structure.
2. Architectural : A superstructure of economical
materials was constructed over the pump room in the
dry well (See Figure 12), and constructed of a structural
steel frame with insulated metal siding. The siding was
made up of an exterior steel panel with a paint finish
and an interior steel panel with a baked-on finish and
1-1/2 inch thick fiber glass insulation betwee i the
panels. Hollow metal doors and frames and aluminum
louvers were provided in the walls.
The roof was constructed of four sections made up
of 1-1/2 inch deep, formed steel decking. The outer two
sections were spot welded to the steel roof framing and
the inner two sections were bolted to the steel framework
to provide for the removal of the pumping units. A vapor
barrier, 1—1/2 inches of rigid insulation, a four—ply tar
and gravel roofing was applied over the metal deck. A
metal facia and water dam was installed around the perim-
eter of the roof. Sheet metal downspouts were provided.
Steel stairs were provided for access to the pump room
floor.
The wet well was not covered, but was protected
with a railing around the entire perimeter. Aluminum
stairs were provided in the wet well for access to the
bar racks.
31
-------
I
A
PLAN AT EL+28.5
-------
- - - ____
I -- D’o Stiel 2
. t/’3133
4
FIGURE II
PLAN AND SECTION
33
-------
f-,: ,j t.
D,.q,, _.s Z
Le *rr GcIvs CPv’. l. fr/er ep9ifl9 5 t*fP
(F -, ’ ‘ P9 7V 4’ CP .5ew’r)
— — - — - --. - — — - - - 4
- - — - I T -
.51i, ’:e ‘
-
— i— --—- — -
5fee’ S. f, - j
-
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V i I T
1.’ E L L
P P
H- I
POD r ’
c) ( rn c .df.
• f $u:0’. K; --:9!
SECT ION
34
-------
4 (1
I.;
L /
= JP.;cs ---u
EXISTING
DIVERSION CHAMBER
SC AL C
4 1 0 4 SF1.
_________________________ I /4 • I•- C
R-D. a---;
4.9•-4• v.,2
.5 -
B-B
FIGURE 12
SECTION
35
-------
‘A,
—a ‘ S—
- S . . .; S
S . ..
S
‘S.
S. —: S. i . . ’.
• SS - . - S. . *.—S- *S .
:e . ’.
“S
- 5- _ S
S S
— -
• * S . . 5 5
S -.5.. ’ . .
S. • S • 0%
S 5 - SS. - •T •• ‘ ‘•
5’ -; -S
.5
S - - • • • • -. ,. . S S - ••:
flS 5I 1’bbS. t... . • . . - S• 5 • •S • .•• - . • -
5 4• . 5— •-• •
-0 — • - 5 -
5 5 .tba,;; .j ‘
• - S
•
Figure 13
supplemental Pumpinçi Station,
Grading for Site
-------
“ ‘‘
/ F.
/ .
/
/ ,
/ . .
t._. —
/ iij
‘F / / /
p - -
-
gi 4 ’ . .. .. . ‘‘ .
“ “ I
r • y _ ’c— — — — - — I I Ii
\ - J I ____
Supplemental Pumping Station /
Erecting Work m i Platform I ____________ ________
-------
r r
Figure l5
Supplemental Pumping Station
Driving Sheet Steel ?iling Coffcrdarn ,
for Substructure
—I•
• : I
1
r
.1
•1
(T 1
r’1
I
-------
- —
-- . 5.
N
N. .
. — - _______S5__
- - \,
0 ,
- S
• _ 5__
- ‘V •
•• • _ . 5__
•
5.
f 4 t ‘ . .. -‘
r i ’ . ‘••
• - ‘ ?
—
5 •_ ’_ _•_ .5
p — 5’
-. . 5-.— .-.-
/ ‘ t L ,
Figure 16
Supplemental Pumping Station
Cross Lot Bracing of
I’
.5 .
It .: - • • • . ‘ - .4
‘ • iP
W I (45 . . 5 .• uit J • . . .. - . . .
• -4 -. •
I
A
f
Th
; •
-I
5 ’
5— Ii
‘ ._f - ‘5--.
5 /
‘I,
I.
‘ 5 - 5555
_ 5 . S..
‘5- 5.
-------
0
.J
Figure 17
Supplemental Pumping Statiofl
Existing 72-Inch
Lower GoodeS Creek ntcrceptiflg Sewer
-------
:
-. b- I - -J — f ,1’
--
r 1 ’.
S1è MJ X -?(
Figure 18
Supplemental Pumping Station
Partially Coii pletcd ‘urnpir g Station,
Discharge Piping and Diver3ion Structur 1 ’ -
I
-
4 - 1- -•.
: . - .- S
-- —
• ? s
L ‘ 4 ‘
I
- r
-------
jL:
I
r.
-----
1’_
Figure 19
:1 Supplemental Pumping Station
_______ nterior View of Sewage Pumping Units
I.-
1;
\ \
/
/
: .
I,
42
-------
\
/:‘ . __________________
- _ i
_
- - Z(__
1
-
“ ‘ ,, - —
r
— t 4 —
— — .4 .,
—
— . ,— # % ‘p — - .-, —
— . ,- .—.- -
T
I
Figure2O - - -.
Supplemental Pumping Station
Exterior View of Completed
Pumping St ition and Oischarga Piping _____________
-------
-S..—— - — - - S_. . S . S
[ - - 1 — __- ___
- — - ... ..
i: -. 5
____ ‘ ‘ — -- 4
- -S. :‘
- -
— - - A - - -4 — .. . 1 .h
a; — — T r
I - - - -. ‘ - - : - - -- - - - - - - -. - - - - - •
-. t - s-S.. i.b.. - -. - - . . . • -., - - •--.
4 . . i. ..-. —- -U
-d
• . 5 ’ i ..• .- - -. - - - S - - ‘ -a -- - - • • 4
- .. S .’_’•c_S ‘.•• ‘. - - .. _ 5• .•.• S • S ‘ - 5 5_Si
- -S • - •• b - - - I .
___ — ‘ • III• ”4I• _ - -
Supplemental Pumping Station • ‘•“ - ‘ - -
Pumping Station Discharae Pipinci , .
and Diversion Chamber i- ., -• - . - . - _-.
-------
‘J.t 1
V
ç ’
/ :..
:
—
a -•-,y
- - -. - ‘-.1 -
Figure 22 -: - • ‘-:
Supplemental Pumping Station ’ .; -;
View of Open Wet Well
and Enclosed Pump Room ... .‘. ‘.
• p••.
- -
I
-------
,?
r-
- r • _______
Figure 23
Diversion Structure
Breaking Out Opcninas for Discharge Pipe
and Ternpor ry Bulkhead
1’
/1
41
• r
- - - J’;
‘2 - -
-
•1
•
- ‘;:
-, - I -
k
J
I
L
-------
3. Piping and Equipment : Two vertical nonclog raw
sewage pumps with close-coupled wound motor drives,
supported directly on the pump, were installed, Each
pumping unit is capable of variable speed operation.
Each unit is capable of puin?ing 50 mgd t maximum
speed and 15 mgd at minimum speed. The pumps are
provided with grease seals.
The suction of each pump is a 42-inch steel pipe
with a 42-inch sluicq gate at the end in the wet well
for shutoff. A 36-inch steel discharge pipe with
sleeve type couplings is provided from each pump
forming a siphon at the top where it leaves the pump-
i-q station and discharges down into the nearby existing
diversion structure.
Bar racks which may he cleaned manually are pro-
vided in the wet well ahead of the suction sluice
gates. Figure ] 2 illustrates the arrangement of the
piping and equipment.
The chlorination piping in the exist Lng diversion
structure was modified to provide facilities for the
addition of chlorine downstream of the pump discharges.
Valving is provided in the new chlorine piping so that
the chlorine may be applied at the entrance of the
96—inch force main wnen the Main Pumping Station is
in operation, or downstream of the Supplemental
47
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Pumping Station pump discharges when the Supplemental
Pumping Station is in operation.
Metering equipment include meters and registers
for each pump suction and discharge pressure and the
pump speed. With this information and the head-caoacity
curves for each pump, the approximate pumping rate for
each pump may be determined. The meters and registers
are located on an instrument panel inside the building
at the ground floor level.
Provision for manual or automatic control of the
pumps is provided in the pump control system. The
variable speed control system for both pumping units
consists of autow tic speed ontrol arranged to sense
the liquid level in the wet well. The wet well level
as sensed by the liquid level control adjusts the
liquid rheostat connected in the secondary of the wound
rotor motor for pump speed control. External heat
exchangers are provided, for Lhe liquid rheostat,
consisting f a radiator and fan mounted outside the
pumping station structure. The speed control is
designed to start the lead pump, naintain a constant
wet well level until the lead pump is at maximum speed
then start the second pump and both pumps then operate
at reduced speed maintaining a pre-set wet wel]. level.
An alarm system includes an annunciator on the pump
control center and an outside horn and a flashing
48
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light to give an alarm in the event of equipment
failure.
4. Electrical System : The electrical system for
the Supplemental Pumping Station consists of a sub-
station near the pumping station which is supplied
from a 13.2 kv VEPCO overhead line and supplies power
to the Supplemental Pumping Station at 2,400 volts.
An auxiliary station transformer located outside
the pumping station structure is provided to supply
station pcwer at 480/277 volts for heating, ventilating,
lighting and other auxiliaries.
The switch gear, primary control and secondary
controls are mounted on a concrete slab at ground floor
level inside the superstructure of the pumping station.
Figure 24 shows a simple one—line diagram for the
station’s electrical arrangement.
i. Heating and Ventilating : An exhaust fan with a
capacity of 1,000 cfm mounted on the roof provides
continuous ventilation of the Pump Room and dry well.
The roof exhaust fan’s duct carries down into the
Pump Room or dry well to just above the pump suction
ccnnection providing an exhaust of about 6 char ’ies
per hour for an effective operating height of 10 feet.
A 3-foot by 1-foot 4—inch high manually operated
49
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5. t e —
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ONE LINE DIAGRAM
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50
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FIGURE 24
SUPPLEMENTAL PUMPING STATION
ELECTRICAL-ONE LINE DIAGRAM
51
-------
- -
louver is provided in the superstructure wall to
provide for the continuous air intake.
Another exhaust fan with a capacity of 6,000
cfm is mounted in the Pump Room about 10 feet above
tne lower floor. This fan is thermostatically con-
trolled to provide heat removal and discharges throuc,h
a gooseneck on the roof of the superstructure. Inter-
locked with this exhaust fan is a 4-foot y 8—foot
high motor—operated louver located in the super-
structure wall, which provides the intake to the
superstructure of the required amount of outside air.
Three 20-kw thermostatically controlled electric
unit heaters are provic ed for heating the Pump Room
and superstructure.
B. Description of the ‘z3ulkhead ’
The installation of the bulkhead in the existing
South Junction Chamber required design because of the
unusual structural aspects.
The walls of the existing South Junction Chamber were
not designed structurally to restrain the greater loads
imposed on them by the increase in internal hydrostatic
pressure; an 8-foot by 8-fot opening in the south wall
lGading to the Main Pumping Station was to be bulkheaded.
The entire structure, including the north (back) wall and
the side walls, was engaged,structurally, to carry the loads
52
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imposed by the severe hydraulic conditions after the
installation of a bulkhead.
The bulkhead had to be installed while the sewage
was flowing through the junction chamber. The bulkhead
was prefabricated of welded steel plates, beams and
angles with a 3-fcot by 4-foot sluice gate mounted at
the center near the bottom and rubber seals on both sides
and the bottom. The bottom of the 8-foot by 8-foot
opening was flat with no sill for bottom support of the
bulkhead. It was necessary to design the bulkhead for very
small deflections to prevent leakage.
The bulkhead was designed by a stiffness method using
an IBN 360 computer. A program was developed which deter-
mined all reactions, shears and moments of all points
considering the effects of the various deflections.
The bulkhead was structurally tied to the back wall
with the use of tie rods and an anchor beam placed outside
of the structure against the back wall. This permitted
the hydraulic loads imposed on the bulkhead to be trans-
mitted into the entire structure, even utilizing the side
walls, and preventing the south wall from receiving the
bulkhead loads for which it was not designed. Figure 10
illustrates the bulkhead as installed. It was necessary
to remove a portion of the top of the concrete structure
to permit the installation of the bulkhead.
53
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Figures 25 to 30, inclusive, illustrate the installation
and removal of the temporary prefabricated bulkhead placed in
the inside south face of the special structure to divert raw
sewage to the Supplemental Pumping Station thile making con-
nections to the new Grit Removal Facilities.
C. Method of Accomplishment and Costs
To obtain pumping equipment as quickly as possible, the
pumping - uipw nt was purchased with a separate contract prior
to thr ..esign of the structure..
To obtain the most readily available equipment, the
.iecifications permitted the furnishing of new or reconditioned
pumping units consisting of two or three vertical or horizontal
electric motor driven units. The type of controls permitted
were squirrel-cage motors with adjustable speed magnetic
drives, wound rotor motors with liquid rheostat variable
speed controls in the secondaries of the motors. Two bid
proposals were received for the above pumping equipment and
controls. Both proposals were for new equipment. One pro-
posal offered two vertical wound rotor motor drive units
each with a maximum capacity of 50 mgd; the other proposal
offered three horizontal units with wound rotor motor drives
each having a maximum capacity of 30 mgd. Each proposal in-
cluded liquid rheostat variable speed controls.
Although the bid prices of the three horizontal unit
proposal was slightly less than that offered with the two
unit vertical proposal, the two vertical units were selected
54
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I
1I
U’
Is . —..
- .r .,(_•. — S
Figure 25
South Junction Chaiiibcr
Transporting Prefabricated Special
Bulkhead to Sitc
-ì
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Figure 2b I
Lowe ring Dulkhea into piaceL t _ L i ___________
ii _ 1 L_i
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Figure 27
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S
South Junction Chamber -
South Face of Chairber . -
Showing Bulkhead in Place - .
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Figure 4 -. -
South Junction Chamber
Preparation for ‘ .,‘ .ç ) ‘ e ’
Constructio!L .pf New Junction
U’
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N
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H
-se. 4 aa 4 ’
gure l9 .rs I $ r
South Junction Chanter t ,‘. _— ‘ -- — - •
Placing Reinforcing Steel for Condui* C’ - - ‘ - ---
Between New Junction Chamber - - a - ’
and Inlet Chainbe r tIJ
• . -•.•--.•— , —.-- —-‘- -—- -- -- —“ - ra
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South Junction Chamber
Removal of Prefabricated Bu1kheadL
60
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because a much smaller pumping station structure could be
built and the savings in cost of the smaller structure would
more than offset the small additional cost of the equipment.
The total amount of the bid for the two vertical pumping
units and all specified controls was $149,900.00.
D. Design Time
The design of the Supplemental Pumping Station and
Appurtenances began in January, 1970. Bidding documents
for the pumping equipment and controls were prepared and
bids were received on May 14, 1970. The Contract was
awarded on June 23, 1970, and the design of the Supple-
mental Pumping Station was begun to accommodate the specific
equipment to be provided. On July 20, 1970, the preliminary
Plans were reviewed with representatives of the Federal Water
Quality Administration, the Virginia State Health Department
and the Virginia State Water Control Board. The design con-
cept was approved at that meeting, and at the end of July,
1970, the FWQA approved the Plans for the Supplemental Pumping
Station. All design work was completed and negotiations with
Contractors were begun for the accomplishment of the Contract
work. Contracts and change orders to existing contracts were
signed in December, 1970, and on—site construction was begun
February 19, 1971.
61
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SECTION V
‘ IIIE CONcTRUCTION
The design of the facilities necessary to avoid
bypassing was initiated following acceptance of the Grant
Offer on January 26, 1970. The work was to be developed
in two parts; pumping equipment and the Supplemental
Pumping Station structure itself.
On April 21, 1970, the Federal Wacer Quality
Adninistration approved the Plans and specifications for
the pumping equipment. The contract was advertised on
April 24, 1970, with bids to be received on May 14, 1970.
The award of the contract was approved by t e FWQA and the
contract was subsequently executed on June 24, 1970. Pump
tests were witnes3ed on January 25 and 26, 1971. All
equipment under the contract was received by the end of
May, 1971.
The preliminary design of the “Supplemental P nping
Station - Structures” and the design of the temporary
bulkhead for the existing junction chamber were substantially
complete by June ii, 1970. A meeting was helu on July 20,
1970, to review the cost estimates for the pumping station
and bulkhead. Present at this meeting were representatiVes
of the Federal Water Quality Administration, the State
Health D2partnent, the State Water Control Board and the
consuita its of the City of Richniond.
At the meeting, the plans for the pumping station
structures were submitted for approval. As a result of
62
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that meeting, it was agreed to redesign the electrical
service to realize a savings of approximately $7,000
and to eliminate the Dahl flow tubes. These changes
were to be incorporated in a change order to the work
presently underway at the Wastewater Treatment Plant.
The Federal Water Quality Administration notified
the City on July 29, 1970, that they approved the design
of the Supplemental Pumping Station - Structures,
incorporating the changes discussed in the July 20, 1970
meeting.
Actual construction of the Supplemental Pumping
Station — Structures was begun on February 19, 1971, with
the driving of sheet piling completed on April 7, 1971.
Excavation ‘as essentially complete by September 4, and
concrete work was accomplished between September 10 and
November 23, 1971. The assembly of the superstructure,
electrical work and the installation of equipment and
coritros were all undertakEn during th period from
November 23, 1971 to February 1, 1972.
In addition to the two main parts of this project,
(pumping equipment and pumping station structure) numerous
smalJer projects were necessary to allow the Supplemental
Pumping Station to function properly. These various
projects were achieved through change orders and various
contracts. The various Contract Divisions for work at
the Wastewater Treatment Plant, the change orders,
63
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separate contracts, dates of issue and a brief description
of the work covered by each change order or contract are
summarized below:
Change
Order
Contract Number Date Description
Div. x 7 4-17—70 For furnishing all labor,
material and equipment for
the construction of the
following items (see projosal
by Contractor dated April
13, 1970, and proposed
Construction procedure):
1. Outfall Chamber No. 3,
as illustrated on Supplementary
Sheets 4 to 6, inclusive
revised !‘ arch 19, 1S70.
2. New Diversion Chamber and
Sewer as illustrated on
Supplementary Sheets 1 and 2,
dated October, 1968.
Div. X 9 10-10—70 Change Order No. 9, “Modi-
fication of Junction at River
Crossing” per letter of
January 9, 1970, from the
City Manager addressed to
the State water Control Board,
including Attachment “A”.
Part D of Attachment “A”,
Modification of Junction at
River Crossing — Construction
Grant. (See English
Construction Company, Inc.
proposal dated September 25,
1970, and Plan Sheets Nos.
1, 2 nd 3 with Specifications.
64
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Change
Order
Contract Number Date Description
Divs. XII
and XIII 2 9—2—70 For furnishing all labor,
materials and equipment
for construction of a sluice
gate chamber in the existing
raw sewage conduit adjacent
to the e:cisting prixrary
tanks (See Sipplemental
Sheet No. 2 and English
Construction Company
proposal).
Divs. XII
and XIII 3 10—10—70 Research and Development
on a Supplemental Pumping
Station and on the Modi-
fication of Junction at
River Crossing p r letter
of January 9, 1970, fi ,m
the City Manager addressed
to the State Water Control
Board including Attachment
“A”
Part A of Attachment “A” -
Pumping Facilities Research
and Development Grant.
(See Part A of English
Construction Company, Inc.
proposal dated September
23, 1970 and Plan Sheets
Nos. 1 through 13, with
Specifications).
Part D of Attachment “A” —
Modification of Junction
at River Crossing — ? search
and Development Grant (See
English Construction Company
Inc. proposal dated
September 23, 1970, and
Plan Sheets Nos. 1, 2 and
3 with Specifications).
65
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Change
Order
Contract Number Date Description
Divs. XII
and XIII 4 10—10—70 Construction of a
Supplemental Pumping
Station and Modifications
of Diversion Structure per
letter of January 9, 1970
from the City Manager
addressed to the State
Water Control Board including
Attachment “A”.
Part A of Attachment “7 ”,
Pumping Facilities -
Construction Grant. (See
Part A of English Construc-
tion Company, Inc. proposal
dated September 23, 1970
and Plan Sheets Nos. 1
through 13 with Specifica-
tions).
Part B of Attachment “A”,
Modification of Diversion
Chamber — Construction Grant.
(See Part B of English
Construction Company, Inc.
proposal dated September
23, 1970 and Plan Sheets
Nos. 1 through 13).
Divs. XII
and XIII 5 10-21-70 For furnishing materials
and labor for construction
of and installation of a
steel bulkhead in the ef f—
luent channel of the
existing Preliminary
Sedimentation Tanks per
Supplemental Sheet No. 3
and the English Construction
Company proposal of October
19, 1970. This work is to
be accomplished with the
existing plant in operation.
66
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Change
Order
Contract Number Date Description
Supplemental 6—24-70 Furnishing and delivering
Pumping complete, the new or
Station - reconditioned used pumping
Furnishing equipment consisting of
Pumping two or three vertical or
Equipment horizontal, electric motor—
driven pumping units and
all equipment to provide
a complete pump control
system.
Supplemental 5—19-71 For furnishing a ground
Pumping detection alarm system,
Station — fused switch and additional
Furnishing motor starters, and the
Pumping deletion of the window—type
Equipment current transformers and
ground fault relays. No
extension of time is
required.
Electrical 3—22-71 Furnishing and installing
Substation the transformers, poles,
fence, and related equipment
to completely construct the
substation.
The existing diversion structure was altered during
the period September through November, 1971, with the
installation of a wooden bulkhead.
Work on the connection of the grit removal facilities
continued until the Wastewater Treatment Plant was flooded
in June, 1972. At the time of that flood, work was essen-
tially : p1etc on construction required for connection of
the grit channels. Following the emergency repair work
was begun on the Grit RE:iioval Facilities. This period
OC r pair required approximately three months. By August,
6
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1972, it was anticipated that connections could be made
and the Supplemental Pumping Station could be shut down
about the beginning of October.
The flood in the early part of October forced the
station out of service frcm October 6 through October 9,
1972. Once again, the grit channels were flooded and
repairs were completed by the beginning of December.
Attempts to reactivate the Main Pumping Station were
hampered by damage caused by the flooding and idleness,
but undetected during repair work. Complete repair work
on the Supplemental Pumping Station made necessary by
the June, 1972 flood could not be acccinplished until the
Main Pumping Station was reactivated. The floods of
June and October, 1972, caused a delay of approximately
seven months in the corrpletion of the supplemental pumping
operations.
The flood of 1 ugust, 1969, while not occuring during
the construction of the Supplemental Pumping Station and
appurtenances did contribut’ to delays in the construction
schedule for the Grit Removal Facilities. The irtended
period of plant shutdown had to be delayed from September
15, 1969, unt5l November 1, 1969. Before the plant shutdown
was to begin, howEver, bypassing was ruled out and
circumstances led to the filing of the grant application
on November 14, 1969.
68
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Initiating Construction
The connection bet.;een the South Junction Chamber
and the Main Pumping Station was closed by the installation
of the specially designed bulkhead. Modifications to the
South Junction Chamber and preparatory work for the instal-
lation of the temporary bulkhead was begun on October 12,
1971, and was completed by January 31, 1972. At that time
art attempt was made to install the bulkhead in accordance
with the suggested procedure outlined in Figure 8. The
attempt to install the temporary bulkhead wa unsuccessful
because the Contractor failed to ascertain a dimension in
the field as stipulated in the design Plans. The bulk-
head was removed, tered and reinstalled on February 1,
1972. Final adjustments on equipment and controls in the
SupplerLental Pumpinq Stat.On were made between February 2
and February 9, 1972, when the sluice gate was closed on
the temporary bulkhead in the south Junction Chamber arid
the Supplemental Pumping Station went into full operation.
The temporary bulkhead sealed the opening excellently,
allcwing very littic leakage.
Termination of C’MmtructiOfl
In December, 1972, the sluice gate in the temporary
bulkhead was opened at various time. to test the operation
of the grit channe s and the Main Pumping Station. These
tests were run on an interr. ittent basis until January 3,
69
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1973. By FebrUarY 14, 1973, preparationS were being
made to restore the stiucture and equipment to preflood
conditions.
The chronology of principal events bearing on the
development and .Logress of the work associated with the
Supplemental Pumping Station is shown graphically on
Figure 31- The construction costs are summarized as follows:
DivS. XII
and XIII
Electrical
Subtotal -
Outfall Chamber No. 3
and New Diversion Chamber 81,467.00
Modification of South
Junction Chamber __________
Sluice Gate Chamber at
Primary Tanks
Mech. & elec. work
P.S. & Diver. Structure
Bulk. in Primary Tanks
Substation (original
Contract)
Structures and
Appurtenances Cost
24,900.00
$106,367 .00
12,800.00
145,100.00
317,400.00
7,495.00
$482,795.00
10,470.00
$599,632.00
Supplemental Pumping
Station, rurnishing (original
Pumping Equipme’ t Contract)
Electrical controls
Subtotal — Furnishing Pumping
Equipment Cost
Total Construction Cost
149,900.00
2,139.30
$152,039.30
$751,671.30
Contract
Div. X
Co St
70
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The total cost for pumping equipNeflt is $152,039.30 and
the cost of the Supplemental Pumping Station and
appurtenant structures is $599,632.00, including thn cost
of the Virginia Electric and Power Company work on the
electrical substation. The total of all construction
costs associated with the Supplertental Pumping Station
and Appurtenances is $751,671.30.
Sumxnar
The total cost of the Supplemental Pumping Station
and appurtenant work has been defrayed in part by
Research and Development Grants and in part by local funds.
The allocation of costs is as follows:
Const. R & D
Grant Grant Total
Encjir.eeriflg 36,095.34 1,576.61 37,671.95
ConstructiOn 454,532.00 297,139.30 751,671.30
Operation — 99,734.93 99,734.93
Administration — 6,47 .7 8 6,479.78
Total $490,627.34 $404,930.62 $895,557.96
71
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Review of Shop Drawings - Pumpmg Equipment
I 1t
IU, I
ATSTO 14
Construction - Oivlsion I
Flood Delays - Division I
— — I Restudy
U N2 Administrative Review
RE R.tl.sign
1
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Construction — Supplamental Pumping Station
Operation - Supplemental Pumping_Station
1
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72
-------
S97 1 972 973
o N ________
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FIGURE 31
CHRONOLOGY
73
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SECTION VI
THE OPERATIONS
A. Operation Phase
The Supplemental Pumping Station was tested on February
3, 1972, for a period of 7 hours. On February 9, 1972, the
station began full-time operation at 9:10 A.M. The first
full day of operation was February 10, 1972, and the station
continued to operate until the flood caused a shutdown at
12:00 P.M. on June 22, 1972. The station was restarted at
11:30 P.M. on July 3, 1972.
Another flood required the station to be shut down from
6:00 A.M. October 6, 1972, to approximately 8:00 P.M.
October 9, 1972.
The Suppleriental Pumpirg Station was shut down on
Janu iry 21, 1973, and the Main Pumping Station was restored
to service.
At the time of the initial start—up of the Supplemental
Pumping Station, it was anticipated that the connection to
the New Grit ChaNber could be made during the month of June,
1972. The flood of June, 1972, damaged motors, controls
and othe’ equipment in the Supplemental Pumping Station and
the Lransformers at the VEPCO substation. The two 500-horse-
power motors were removed with a crane through a hole cut in
the roof of the station and sent to the General Electric
service facility in Richmond. One of the motors was returned
and remounted on July 3, 1972. This installation was used
to pump and chlorinate a portion of the sewage flow. The
74
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second motor was returned and installed on July 4. The
station was operated rianually, since the automatic controls
were still damaged. The transformers in the VEPCO substation
were also repaired by the local General Electric service
facility.
By August, 1972, repairs on flood damage to the new
grit tanks had progressed sufficiently to expect that con-
nection could be made at the beginning of October. The
flood in October or.ce again flooded the grit tanks and
caused damage. The Supplemental Pumping Station had been
stripped of readily removable equipment and required only
that it be pumped out and w ’shed down before the electrical
equipment could be reinstalled.
Repairs to the grit tanks were essentially completed
in November and connection was scheduled for December.
During Deceivber, 1972, and January, 1973, repeated atterL tr
were made to reac tivate the Main Pumping Station with
new grit tanks on line. Operational problems were a . Luted
to the flooding of equipment and to the long period
which the equipment remained idle. The problems werL
finally resolved and the Supplemental Pumping Station was
secured on January 21, 1973.
B. Operation and Maintonance
Staff
The staff required for the operation and maintenance
of the Supp emental Pumping Station has been drawn fron
75
-------
the personnel regularly employed at thu Wastewater Treatment
Plant. Overall daily supervision was provided by the plant
superintendent and this required approximately ten percent
of his tji; e. Five shift supervisors provided immediate
supervision of operating personnel and this required ten
percent of their total time. The total of eight shift
operators spent approximately 100 per cent of their time
attending the equipment. These eight operators comprised
four gas engine operators and four gas engine attendants.
These men were normally employed in the Main Pumping Station
and are familiar with large pumping equipment and drives.
Control System
The Supplemental Pumping Station operated in response
to an increase or decrease in the wet well level. The
primary control sensor for automatic pump operation was an
air bubbler tube suspended in the wet well. The pressure
changes on the bubbler system caused by fluctuations in the
sewage level in the wet well were converted to an electric
signal which controlled pump motor speed and pumping sequence.
The “start” and “Stop” sequence of the infinitely variable
speed pump motors could be 3elected and the wet well eleva-
tion at which the pumps start and stop was adjustable. The
approximate elevations were as follows:
Start Stop
Lead pump El.-5.5 El.-5.6
Second pump El.-4.75 El.-4.85
76
-------
The sequence of operation used with this control
system is described as follows:
1. Jhen the wet well evel reaches the “start’ t
elevation for the “lead” pump, the motor shall
start at minimum speed.
2. The “lead” t’ it shall increase in speed as the
wet well level te.ids to rise. It shall increase
in speed to the maximum pump speed maintaining a
constant level.
3. When tl “lead” unit has reached its maxir um
speed and the wet well level has risen to the
corresponding level for the “start” of the second
unit, the “second” pumping unit shall r ,tart. The
“lead” unit arid “second” unit shall adjust to the
same speed.
4. The “lead” unit and “second” unit shall increase
in speed as the wet well level tends to rise.
They shall increase in speed to their maximum
pump speed with the rising level.
5. ? the wet well level tends to drop, the “lead”
unit and “second” unit shall decrease in speed
until their total capacity is less than the
capacity of the “lead” unit running at maximum
speed. The “lead” unit shall immediately in—
crease in speed so its capacity equals the total
before the “second” unit stopped.
77
-------
6. As the wet well level tends to drop, the “lead”
unit shall decrease in speed to maintain a con-
stant level until its capacit)’ is that of the
unit running at minimum speed. At this time the
“lead” unit shall stop.
The characteristic curves of the two pumping units
installed in t!ie Supplemental Pumping Station are presented
as Figure 32.
c. Data Collected
Data collected on a regular basis during operation of
the Supplertental Pumping Station include: James River
water quality data, pumping unit suction and discharge
pressure, uinping unit rotational speed, operating logs,
a di.ary maintained by the resident engineer at the treat-
ment plant, and the treatment plant operating records.
The river water qualit.y data is based on weekly samples
taken by the Richmond Department of Public Utilities at six
stations on the James River. Samples are analyzed for
ter.Dorature, pH, dissolved oxygen, 5-day mOD, total bacteria
and coliforms.
Pumping unit suction and discharge pressure and rota—
tiondl speed were recorded on 24—hour recording charts.
Each unit has, therefore, three separate operational charts
for each 24-hour period.
7n
-------
- .., . . .C- .fl •. -ta. . r,- .. - . -. -. - -. . — — -. - — .• — -
Operating logs were maintained by the treatment plant
personnel on a 24—hour basis. The information regularly
recorded on these logs was:
Wet well level
Pump hour meters
Watt hour meters
Suction and discharge pressure
In addition, operator’s comments were recorded.
The resident engineer’s diary provides a record of con-
struction and oper-ition sequences and describes activities
and problems encountered during the project.
D. r valuation of Data
The available data on pump speed, st.ction and discharge
head and the pump characteristic curves can be used to
estimate the axrount of sewage handled by the Supplemental
Pumoing Station. The developirent of the complete pumping
record from their data would involve extensive data logging
and computations. The treatment plant records, theretore,
have been studied to establish an alternate record of pumpage.
The treatment plant flow record is obtained from an effluent
weir. Comparison of the flow data from the two sources for
selected periods of operation indicate good correlation.
The flow data reported herein, therefore, is that obtained
from the effluent weir at the treatment plant. An estimated
curve showing comparison of the two sources of flow data is
included as Figure 33.
79
-------
I-
taJ
I d
•-- 60
z
a
I d
5O
C.,
z
.40
-J
d
0
I-
20
80
-------
- - URE 32
ES
81
-------
Pdoto:
Supplomentol Pumping Station flow vaIue
were computod from chart recordo.
80
60
Ii : 00T
20 40 80 100 120
SUPPLEMENTAL PUMPiNG STATION
FLOW — MCD
FIGURE 5
CAUBRATION CURVE
PLANT EFFLUENT WE R VS SUPF P. STA. FLOW
82
-------
Complete flow records are available for the period
beginning with the start-up of the Supplemental Pumping
Station and ending with the facilities shutdown caused by
flooding. A record of daily flow averages for that period
is presented on Figure 34. During this period of record,
the maximum daily average flow was 61.3 mgd on February 20,
1972. The minimum daily average flow of 36.6 ingd was handled
on May 3, 1972. The estimated average dai .j flow handled
by the Supplemental Pumping Station during the period when
the weir was out of service was 42.6 mgd, based on the
previous 418 days of plant operation.
The monthly averages of flow received and pumped for
the period covering the operation of the Suppler ental
Pumping Station and nine r onths previous are shown in Table
1. These figures are presented to indicate the periods for
which flows had to be estimated.
The total flow pumped prior to after the floods
is 13,125 mg.
The estimated aiqount bypassed due to the floods is
680 mg, which is approximately 4.5 percent of the total
flow tributary to the treatment plant during the project.
83
-------
80
70
C)
0
I-
z
w
-J
Ii
U i
30
I.-
z
d
-J
a. 20
I0
0 IIillIttlIItIIIllIlIIIIIttI 1111111111111111111111111111
0 0 0 01
C) (%J - cg
Fsbruary March
972
MONTH
84
-------
I I III I 1 I I II 1 [ 1 1 1 111 11 II I i I I I 1 1 1 1
0
c,J
April
IiiiIiIII IIiIIi IIIIIIIiIIIiI1IlI11Ii_1_ I__I _ I_ I
May
972
0
oJ
MO NT H
ol
In—
0
01
June
FIGURE 34
WASTEWATER TREATMENT
PLANT EFFLUENT
PLANT
FLOW
)
0
85
-------
TABLE 1
Supplemental P. 5.
Flood — SP.S. out
Flood — S.P.S. out
Through January 3,
RICHMOND, VIRGINIA
MONTHLY FLOW SUMMARY
OF
FLOW
MONTH DAYS
MCD
NUMBER AVERAGE MAIN P.s. sup.r.s.
FLOW
DIFFERENCE
MC
MC
FLOW
MC
f Tho
1,380
1,170
1,260
1,220
1,450
1,170
1,090
1,230
390
TOTAL FLOW
MC
1971.
1 ay
( June
31
30
41.183
46.132
1,280
1,380
PRIOR TO
C July
31
37.714
1,170
OPERATION
C Aug.
C sept.
( Oct.
( Nov.
C Dec.
31
30
31
30
31
40.672
40.638
46.932
39.017
35.204
1,260
1,220
1,450
1,170
1, 90
1972
C Jan. 31 —
Feb. (* ] .) — 29 —
39.703 —
9.822
— — —
T,5s5
1,20
1,440
March 31
April 30
May 31
June(*2) 30
Ju ly(*2) 31
Aug. 31
Sept. 30
Oct.(*3) 3].
Nov. 30
Dec. 31
1973 Jan. (*4) 31
TOTALS DURING OPE RAT ION
44.497
43.390
46.406
47.95P
42.6
42.6
42.6
42.6
42.6
42.6
42.6
660
65
1,380
1,300
1,440
1,000
1,180
1,320
1,280
1,170
1,280
660
65
390
140
150
1,380
1,300
1,440
1,390
1,320
1,320
1,280
1,320
1,280
1,320
130
(*1)
(*2)
(*3)
(*4)
began operations at 9:00 A. M., robruary 9.
of operation 10 days and 23 1/2 hours between June 22 and July 3.
of operaticii 3 days and 14 hours between October 6 and 9.
when the Supplemental Station was put on Rtandby.
-------
SECTION VII
DISCUSSION
A. General
The purpose of providing a Supplemental Pumping Station
was to protect the water quality of the James River. Avail-
able water quality data is based or. weekly sair.ples taken
by the r ichinond Department of Public Utilities. The
sampling points along the river are shown on Figure 35.
River san pling data ace summarized in Tables 2 and 3 for a
period of record preceding operation of the Supplemental
Pumping Station -nd for the period of operation, respectively.
A comparison of maximum and minimun’ concentrations of
dissolved oxygen and BOD 5 in the river by months is pre-
sented as Figures 36 and 37, respectively. These data
indicate that dissolved oxygen levels were maintained at or
above those for the period of record for stations down-
stream of the Wastewater Treatment Plant. Likewise, the
concentration of 5-day biochemical oxygen demand during the
period of operation is lower than that during the period of
record downstream of the plant.
A record of the loadings on the Wastew.. ter Treatment
Plant is presented in Table 4. This table covers not or’y
the period of operation of the Supplemental Pumping Station,
but the nine-month period immediately preceding. The tabu—
lation shows that during that nine-month period, the Waste—
87
-------
FIGURE 35
RIVER SAMPLING STATIONS
I
S.T.P
SCALE
048
2 6 io,cEOFT.
LEGEND
Boulevard Bridge
Intermediate Terminal
Light 68
/ Dupont Intake
/ Light 166
88
-------
TABL ; 2
RICHMOND, VIRCINIA
River Sampling Data
July, 1963—June, 1969
Station 2 Station 3 Station 4 Station 5 Station 6
DO BOD CO BOD DO BOD DO BOD DO BOD
Month % Sat mg/i % Sat mg/r % Sat mg/i 5 % Sat mg/i5 %Sat mg/i5
Jan. 99 3.2 99 3.5 98 4.7 97 4.8 96 5.1
Feb. 97 2.5 90 3.6 99 4.9 99 4.1 98 3.7
March 96 2.5 97 2.5 99 3.5 98 3.6 97 3.6
‘0 April 96 3.1 93 3.7 89 3.7 84 3.9 83 4.3
May 93 2.7 91 2.9 83 4.3 75 4.4 75 3.9
. T une 94 1.9 84 3.4 62 4.6 54 4.2 51 4.(
July 91 2.2 63 3.5 32 5.3 22 5.6 27 6.1
Aug. 89 2.6 65 3.7 27 6.6 18 6.4 27 8.1
Sept. 87 2.1 65 3.5 19 8.2 14 7.2 15 7.5
Oc!. 91 2.3 87 3.5 59 .7 61 5.4 56 5.5
Nov. 96 2.5 92 3.4 76 6.9 60 6.0 61 4.8
Dec. 97 2.3 98 3.6 97 5.2 96 5 ,4 93 5.2
Aver. 94 2.5 8o 3.4 70 5.3 65 5.1 65 5.2
-------
TABLE 3
RICHMOND, VIRGINIA
River Sampling Data
Fcbruary, 1972— December, 1972
Station 2
DO BOD
% Sat mgi
56 1.8
93 1.7
69 1.3
78 1.2
Station 3
DO DOD
% Sat mgi
97 1.3
97 0.4
87 1.7
88 2.1
station a
DO DOD
% Sat mg /
94 1.9
98 2.0
90 2.3
90 2.2
Station 5
DO DOD
°o Sat m9/
94 1.9
93 2.1
84 2.8
92 3.0
Station 6
DO BODç
% Sat mg/i
95 3.1
98 0.9
94 2.0
89 2.2
MO nth
Feb.
March
April
0
!.lay
June
July
75
3.2
100
1.0
100
3.0
92
2.4
88
3.4
Aug.
73
5.7
98
1.7
95
0.9
98
2.0
94
2.4
Sept.
76
3.7
97
4.8
80
4.6
74
4.1
80
3.2
Oct.
88
5.1
71
2.7
96
1.0
91
2.6
81
6.6
Nov.
78
1.2
84
1.6
83
1.0
83
2.4
83
2.6
Dec.
58
1.4
85
0.9
88
1.1
91
1.0
85
1.4
Aver.
74 2.6 90 1.8 91 2.0
89 2.4 89 2.8
-------
100—
Ataitimum Moniti
az rnMont
Month
I I I I
2 3 4 1
STATION NUMGER
LEGEND
— — — — Period of record July, 1963 through
Period of operation February, 1972
FIGURE 36
June, 1969.
through December, 1972.
JAMES RIVER, DI3SOLVED OXYGEN LEVEL
80—
60—
z
0
U)
0
I-
z
Lu
C)
Lu
a.
40—
20—
0
91
-------
. • • ?-n .
—. -. — w — — s-. —- — tcfl.4, — *fl
Minimum Mo?ith
—
Minin um
2 3 4 5 6
STATION NUMBER
LEGEND
Parlod of record July, 1963 thro h June, 1969.
Period of operation February, 1972 through December, 1972.
FIGURE 37
JAMES RIVER, BIOCHEMICAL OXYGEN DEMAND
--I
Month -O
/ •%.
/
I
/
I
/
10
9
8
7
6
5
4
3
2
0
I
/
/
-j
0
I ’ )
/
/
a,
., —
-------
TABL}: 4
RICILMO I1), VIRGItZIA
TREATMrNT PLANT WADINGS
Month Flow-MGD Suspended Solids 5-Day SOD Suspended Solids Load 50D5 Load
Ave. 1ax. Mm. Average-mg/i vcraçc-nq/1 1000 lbs/day 1000 lbn/mo 1000 lbs/day 100C Ibsftto
Influer.t Effluent Influont Effluent mi. Eff. mi. Lff. In!. Eu. Inf. Elf.
1971 May 41.18 56.24 28.24 161 80 154 95 55.3 27.5 1713 852 52.C 32.6 1635 1010
June 46.13 61.06 37.76 141 72 101 70 54.3 27.7 1630 831 38.8 27.0 1164 810
July 37.71 44.60 23.16 136 67 137 97 42.7 21.1 1323 654 43.0 30.5 1331 944
Aug. 40.67 48.70 35.08 154 76 129 100 52.2 25.8 1620 800 43.8 33.9 1357 1CSO
Sept. 40.64 47.18 27.52 146 76 144 113 49.5 25.8 1485 774 48.8 38.3 1464 1150
Oct. 46.93 59.46 27.68 136 80 104 83 53.2 31.3 1650 971 40.7 32.5 1260 1007
;ov. 39.0 49.00 23.76 140 79 116 87 45.6 2 .7 1368 771 37.7 28.3 1130 849
Dec. 35.20 47.80 25.38 154 84 124 96 45.2 24.7 1400 765 36.4 28.1 1129 871
1972 Jan. 39.70 46.30 28.40 144 88 140 118 42.6 29.1 1477 902 46.3 39.0 1435 1209
Ave. 40.CO 146 78 128 95 49.5 26.5 1518 813 43.1 32.2 1323 989
Feb. 49.32 61.32 32.40 122 87 102 109 50.7 36.2 1470 1 .050 42.4 45.3 1229 1312
Mar. 44.50 57.50 39.14 128 72 117 96 47.5 26.8 1471 831 43.4 35.6 1345 1103
Apr. 43.39 55.36 38.80 150 81 149 100 54.3 29.3 1630 879 53.9 36.2 1618 1086
May 46.40 58.80 36.60 13]. 72 135 .103 50.6 27.9 1570 865 52.2 39.9 1619 1238
.munel’)49.96 60.50 40.24 133 65 130 91 53.2 26.0 1118 546 52.0 36. 4 1091 764
Ju lyO .)42.6* — — 162 72 198 131 57.6 25.6 1210 537 70.6 46.5 1482 976
Aug. 42.6* — — 135 66 150 109 48.0 23.4 1488 775 53.3 38.7 1651 1200
Sept. 42.6* — — 144 74 215 162 51.2 26.3 1536 790 76.5 57.5 2290 1726
Oct.(2)42.6* — — 115 71 159 112 40.9 25.2 1105 650 56.5 39.8 1525 1075
Nov. 42.6* — — 125 73 140 104 44.4 25.9 1332 777 49.7 37.0 1490 1110
Dec. 42.6* — — 101 61 116 83 35.9 21.7 1112 672 41 2 29.5 1275 915
Ave. 44.33 - 131 72 146 109 48.6 26.8 1367 759 53.8 40.2 1510 1137
(1) Figures do not include estimated loadings during the flood of June 23 — J’ily 4
(2) Figures do not include estimated icadings during the flood of October 6-9
* Flow based on average of the previous 418 days
-------
a.
water Treatment Plant received an averaae monthly flow of
40.80 mad, 1,518,000 pounds of suspended solids monthly
and 1,323,300 pounds of DOD 5 monthly. fluring the operation
of the Supplemental Pumpirg Station, and not including the
periods of shutdown caused by flooding, the plant rcceived
an average monthly flow of 44.33 mcd, l,367,00 I pounds of
suspended solids n onthly and l,ilO,)00 pounds of DOD 5 monthly.
The effluent for the nine months prior to operation of
the Supplemental Puripinq station average 813,000 pounds per
month of suspended solids and 989,000 pounds of DOD 5 per
month. During operation, not including shutdowns, the ef-
fluent averaged 759,000 pounds of suspended solids per rionth
and 1 ,l37, 00 pounds of DOD 5 per month. The thfluent and
efflut.it loadings of flow handled by the treatment plant are
shown on Figure 8 (Suspended Solids) and 7 igure 39 (BOD 5 ).
Prior to the operation of the Supple nental Purping Sta-
tion, the Wastowater Treatment Plant renoved approximately
46 percent of the suspended solids and 25 percent of the
BOD 5 . During operation of the Supplemental Pumping Station,
the plant removed approximately 45 pcrc nt of the suspended
so1id and 25 percent of the DOD 5 , which indicates the plant
continued to function at the same level of efficiency.
The floods which caused shutdowns of the Supplemental
Pumping Station allowed the following estimated suspended
solids and DOD loads to enter the river:
94
-------
Est. Load—1000’s of Is .
S ispended
Flood Solids BODE
June—July, 1972 1,000 1,107
October, 1972 164 226
Total 1,164 1,333
The operation of the Supplemental zuruping Station re-
duced the load on the James River, over the entire period
of operation, a total of 6,630,000 pounds of suspended solids
and 4,110,000 pounds of 30D 5 .
The James River flows, average, maximum and minimum, are
tabulated for the period January, 1958 through December, 1972
and are shown in Table 5. The average monthly flows for 1972,
based on preliminary data from the Virginia State Water Con-
trol Board are as follows:
Average Monthly Flow
Month ( CFS )
January 6,180
February 18,295
March 10,180
April 9,492
May 13,036
June 30,906
July 11,302
August 7,859
September 2,486
95
-------
80
70
0
o 60
0
0
U I
C,
>
do
-J 40
-J
30
0
U I
0
z20
UI
U)
C l )
I0
0
MONTH
96
-------
Flood
Jw 9 21 to July 4
Flood
_____ Oct.6 to Oct.9
______r’ ’ I
I
I
I
I
I____ I
I
I
Doc.
ear.
r.
Jw c
July
.
Sept.
Oct
Nc .
1972
MONTH
FIGU E 3a
WASTE 1ATER TREATMENT PLANT
INFLUENT AND EFFLUENT LOADINGS
SUSPENDED SOLGDS
97
-------
80
70
6O
0
0
0
50
w
40
l-J
00
>-
20
I ’ )
to
0
MONTH
96
-------
to July 4
I
I
I
I
I I I
I I
Mar.
Apr.
t oy
June July
1972
Aug.
Sopt.
Oct.
Nov. Doe.
MONTH
FI U E 39
WASTE WAT ER
INFLUENT AND
BIOCHEMICAL
T’ E’ 1 TMENT PLANT
EFFLUENT LOADINGS
OXYGEN DEMAND
6 to Oct. 9
99
-------
TABLE 5
RICHMOND, VIRGINIA
James River Flow
January, 1958 through December, 1972
Average Minimum Maximum Range:
Monthly Monthly Mon hly Max. Minus
Month Flow-CFS Flow-Cr’S Flow-CFS Mm. — CFS
Jan. 7,301 2,903 22,803 19,900
Feb. 10,511 2,957 28,672 25,715
Mar. 12,383 5,117 40,145 35,028
Apr. 9,490 4,466 25,323 20,857
May 7,159 2,887 18,905 16,018
June 5,752 1,184 30,906 29,722
July 2,402 648 11,302 10,654
Aug. 3,413 405 21,710 21,305
Sept. 1,416 202 4,960 4,758
Oct. 4,171 330 18,700 18,370
Nov. 4,507 1,084 19,710 18,626
Dec. 6,455 2,029 20,132 18,103
100
-------
October 18,700
November 19,710
December 20,132
Comparison of the 14-year average in Table 5 with the above
figures for 1972 shows that all months in 1972, except
January and March, :ere greater than the average, most being
significantly greater.
The combination of higher than normal river flows and
continuation of normal treatment processes resulted in an
improved water quality of the James River, even with load-
ings occasioned by the two floods during the project.
B. The Design
The provision of a steel sheeted structure for the
Supplemental Purnpinc, Station proved to be a practical
r ethod of construction. Steel sheeting was driven to rock
and area inside the sheeting was excavated while the walers
were being driven down. Difficulty was experienced in
placing the lower walers because the sheeting had drifted
in toward the center. Another method of construction which
might have lessened the difficulties would be one in which
the sheeting and walers were driven together and in which
the excavation proceeded with the driving. The construction
could then proceed by the sequence of driving, excavating,
and placing walers.
101
-------
While the ground water conditions encountered
at the Treatment Plant site are relatively high, it
was not necessary to weld the joints of the steel sheeting,
however leakage proved objectionable in the steel sheeting
separating the wet well and dry well. The Contractor
welded the seams of this separation wall between El. -2.5
and El. 6.0. After the June, 1972 flood, the City, under
their Annual Welding Contract, completed welding the joints
in this separation wall to ground level. Unfortunately,
this additional welding work was not completed prior to the
October, 1972 flood and consequently, the dry well again
flooded. Construction of this type has also indicated
the need for a sump pump of greater capacity than that
which would be normally provided.
The variable speed control of the pumps appeared to
be a good system, but not without difficulties. The system
req iired a time delay circuit to allow the lead and lag
pumps to change speeds more smoothly, and adjustments
proved very difficult except under low flow conditions.
At low speeds the pump controls tended to “hunt” over a
20-30 rpm range.
The air hose to the bubbler control tube was not
strong enough and ruptured after about one month of
operation.
The pumps and motors operated satisfactorily throughout
the project and appeared to be suitable for this type of service.
102
-------
The electrical system was revised to eliminate the
danger from 50 feet of 2400 volt conduit inside the struc-
ture ahead of the breaker. The transformers at the sub-
station had trouble with overheating and plugging of the vents
in the oil system.
The bar screen platform in the wet well had openings
in the north and south ends which allowed large objects to
get into the pumps during high flow periods. The apparent
solution, which was undertaken, was to provide a “screen”
at these openings.
The temporary bulkhead at the South Junction Chamber
was a successful design. The bulkheading of a chamber
which was not originally designed for the loads appears
feasible. The novelty of this bulkhead is also apparent
in that it can be installed, operated and removed. Should
plant operations require, the bulkhead could be reinstalled.
The removable roof panels as designed are probably
acceptable for relatively continuous operation, but are
not suitable for emergency equipment removal. For emergency
equipment removal, the panels should be designed to be
readily removable.
C. The Construction
Due to the restricted area, the Contractor elected to
drive the sheet piling for the Supplemental Pumping Station
without excavating. This method was successful, but did
prove to be time—consumlling. The elevation of rock was
103
-------
found to be lower than estimated and this caused some
problems since the Contractor had ordered sheeting in
“exact” lengths. Additional sheeting had to be ordered
and welded on to the driven sheeting.
The method of driving without excavation probably
contributed to the sheeting drift toward the center and
caused difficulty in setting the bottom waler.
The existing 72—inch sewer and concrete cradle was
found to have been built differently from the Plans. There
was a misalignment of the sewer, probably due to a ledge of
rock. The sewer was built around the rock ledge and the
concrete cradle was incomplete.
Construction was generally delayed by slow progress
on the pile driving and excavation, the availability of
corner sheeting, structural steel, control circuitry, and
re rking of controls.
The modifications of the South Junction Chmniber proceeded
slowly and intermittently with small crews, but was ready
to receive the bulkhead when the Pumping Station was ready
for operation. Only one day was required to make the
necessary modifications to the bulkhead to accommodate the
different size opening. The installation went smoothly and
the bulkhead required no further modifications.
The final completion of the new Grit Removal Facilities
was delayed twice by flooding. The floods of both June
and October, 1972, occured at approximately the time when
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construction was complete and connection was to be made.
When the grit facilities were finally brought on line,
the Supplemental Pumping Station was on standby service
and adjustments were made both at the gut chamber and
the Main Pumping Station. When fina] adjustments were
completed the temporary bulkhead was removed and the
Supplemental Pumping Station deactivated. The Supplemental
Pumping Station can be reactivated should conditions at
the Wastewater Treatment Plant require.
D. Operations
The operation of the Supplen ental Pumping Station
demonstrated that a constant wet well level was very
difficult to achieve and the fluctuations caused the
lead and lag pump operation to be generally troublesome.
Manual adjustment and operation of the station were often
required. If a pump were shut off without bringing down
the speed, the sewage in the discharge line would rush
back and quickly raise the wet well.
Cleaning of the bar screen was difficult because of
the large fluctuations in the wet well and especially
difficult during periods of high flows when the sidewalk
platform was submerged. During flood conditions, the
bar screen became clogged with debris and caused the
pumps to “hunt” for an operating range, caused debris to
flow over the platform and down through the openings.
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The pump control electrolyte reservoir level required
regular attention and when the level became too low, the
pump speeds would vary erratically over a range of 40—50 rpm.
Also, it was necessary to enclose the electrolyte controls
to protect them from freezing during cold weather periods.
The operation f the temporary bulkhead in the South
Junction Chamber demonstrates that with careful preparation,
design and rabrication a device can be provided which can
divert flow without shutdown. Provision of such a device
should also consider the greater expense required to
insure a workable solution.
The Supplemental Pumping Station was a generally
reliable facility, despite operational r.,oblezns associated
with full automatic operation. Adjustments of the station
controls proved difficult under “on-line” conditions and
the system was often operated manually. The speed of
constructthn, closely followed by operation probably
did not allow an adequate period of training and orientation
for the operating personnel. Consequently, problems did
develop due to inappropriate action or faultly adjustments.
The Supplemental Pumping Station is now expected to
remain available for standby service. During the near
future, repairs to flood damage will be made and the station
restored to pre-flood condition with modifications to the
superstructure roof. The present plan is to operate the
station weekly to insure its continued reliability.
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SECTION VIII
REFERENCES
1. City of Richmond, Virginia. Agreement between City
and Virginia Electric and Power Company, dated
March 22, 1971, to cc.nstruct Supplemental Pumping
Station Electrical Substation.
2. City of Richmond, Virginia. Division X — Grit Removal
Facilities. Change Order No. 7, dated April
17, 1970; change Order No. 9, dated October 10,
1970.
3. City of Richmond, Virginia. Divisions XII and XIII —
Secondary Treatment Facilities - Phase 3. Change
Order No. 2, dated September 2, 1970; Change Orders
Nos. 3 and 4, dated October 10, 1970; Change Order
No. Sr dated October 21, 1970.
4. City of Richmond, Virginia. Supplemental Pumping
Station — Furnishing Pumping Equipment. Change
Order No. 1, dated May 19, 1971.
5. City of Richmond, Virginia. Supplemental Pumping
Station. Daily Operating Records and Operators’
Logs.
6. City of Richmond, Virginia. Supplemental Pumping
Station. Operating Charts for Discharge Pressure —
Pumping Unit o. 1.
7. City of Richmond, Virginia. Supplemental Pumping
Station. Operating Charts for Discharge Pressure —
Pumping Unit No. 2.
8. City of Richmond, Virginia. Supplemental Pumping
Station. Operating Charts — RPM — Pumping
Unit No. 1.
9. City of Richmond, Virginia. Supplemental Pumping
Station. Operating Charts - RPM - Pumping
Unit No. 2.
10. City of Richmond, Virginia. Supplemental Pumping
Station. Operating Charts — Suction Pressure —
Pumping Unit No. 1.
11. City of Richmond, Virginia. Supplemental Pumping
Station. Operating Charts - Suction Pressure —
Pumping Unit No. 2.
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12. City of Richmond, Vira nia. Wastewater Treatment Plant.
Daily Operating Records.
13. City of Richmond, Virginia. ‘leekly Jar es River Analysis
Report. (six sampling points in James River)
14. Greeley and Hansen, Engineers, Chicago, Illinois.
Plans and Specifications dated April, 1970,
entitled “Supplemental Pumping Station —
Furnishing Pumping Equipment.”
15. Greeley and Hansen, Engineers, Chicago, Illinois.
Plans and Specifications dated August, 1970,
entitled “Supplenc .ital Pumping Station and
Appurtenances — Structures.”
16. Jordan, C. L., Resident Construction Engineer.
Notes on Construction and Operation of the
Supplemental Pumping Station.
17. U. S. Department of Commerce, National Oceanic and
Atmospheric Administration, Environmcntal Data
Service. Climatological Data for Byrd Fiel
Station, Richmond, Virginia.
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