AN APPRAISAL OF WATER POLLUTION CONTROL
IN THE
WASHINGTON METROPOLITAN AREA
MARCH 16, 1970
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Kegional Center foi Environmental Infonnatia
VS EPA. Region III
1650 Arch St.
Philadelphia, PA 19103
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AN APPRAISAL OF WATER POLLUTION CONTROL
IN THE
WASHINGTON METROPOLITAN AREA
Prepared by the Federal Water Pollution Control
Administration, Middle Atlantic Region staff for
presentation at the Reconvened Work Session of the
Potomac River - Washington Metropolitan Area
Enforcement Conference, March 16, 1970.
U.S. EPA £cec;k
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LE6END
X. UPPER POTOMAC SERVICE AREA
IT ROCK CREEK SERVICE AREA
IE ANACOSTIA RIVER SERVICE AREA
EC- OXON RUN CREEK SERVICE AREA
JC- WSSD SERVICE AREA
..:....,;.: MAJOR O.C. INTERCEPTORS
"« SERVICE AREA BOUNDARIES
I-PENTAGON STP
Z-ARLINGTON STP
S-DISTRICT OF COLUMBIA STP
4-ALEXANDRIA STP
5-FAIRFAX-WESTGATE STP
6-FAIRFAX-L. HUNTING CR STP
7-FAIRFAX DCGUE CR. STP
8- FT. BELVOIR STP
9-FT. BELVOIR STP
10-WSSD PISCATAWAV STP
FIGURE i
SEWAGE FACILITIES
POTOMAC RIVER WASHINGTON METROPOLITAN AREA
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In April 1969, the Potomac River-Washington Metropolitan Area
Enforcement Conference was reconvened. The Conferees established a
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limit on the total number of pounds of oxygen demanding materials and
nutrients which could be discharged to the Potomac Estuary, and called
§upon the metropolitan area communities to initiate an accelerated pro-
gram of construction of waste treatment plants which would collectively
meet these water quality goals.
The Conferees also adopted a series of recommendations dealing
with the ancillary problems of storm and combined sewers, sedimenta-
tion, industrial wastes, heated effluent, etc. Recommendations of the
State-Federal Conferees were adopted by Secretary of the Interior,
it Walter J. Hickel, on June 13, 1969.
Now, about one year later, we can take a critical look at what
is being accomplished. This statement will present the Federal Water
Pollution Control Administration's (FWPCA) view of where we stand on
W the construction elements of the enforcement conference, including dis-
cussion of FWPCA research and development projects in the Washington
Metropolitan area.
* Loadings to the Estuary
FWPCA studies conducted in the Upper Potomac Estuary during 1969
confirm previous mathematical model studies, and further substantiate
the limits established by the Conferees at the third session of the
Conference in May 1969. The biochemical oxygen demand and nutrient
loadings originally developed for low-flow conditions remain unchanged.
Investigations have been extended to study the effects of varying
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flow conditions and temperatures on the loadings in the upper estuary,
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and to develop loadings for middle zones of the estuary.
Status of Planning for Advanced Waste Treatment
An analysis has been made on the status of planning for advanced
waste treatment at each sewage treatment plant in the area. The status
is reported in Table 1,
d The Blue Plains sewage treatment plant is the key to Potomac
tm River pollution control. About 80 percent of the sewage generated in
the metropolitan area is routed through this one plant. Although a
V complete abatement program requires that the other smaller plants in
the area also provide a high degree of treatment, it is absolutely
J| essential that construction of an advanced waste treatment plant at
Blue Plains proceed as scheduled.
In addition, a thorough evaluation should be made of the arrange-
ment that allows sewage from outside the District to be piped to Blue
Plains for treatment. As shown in Figure 2, approximately 3.9 MGD
flows to Blue Plains via the Dulles Interceptor Sewer from
communities in Virginia; and 25.3 MGD come from Rock Creek Interceptor
* and 56.4 MGD from the Anacostia Interceptor. With continued popula-
tion growth these contributions to Blue Plains are predicted to rise
by 1980 to 37.5 MGD from Virginia and 33.6 MGD from Maryland. The
Potomac Interceptor Sewer was financed by an appropriation from the
' From Great Falls to about one-mile downstream from Fairfax-Westgate
plant.
o/
From above reach to Hallowing Point.
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FUJURK '
D.C. SERVICE AREA SEWAGE FLOWS
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9 U, S, Congress, and the agreements to accept sewage from outside the
District were made possible by Congressional action.
On February 26, 1970, Mr. Norman Jackson, Director of Sanitary
Engineering for the District of Columbia, submitted a report on the
status of the several projects in the District. He reported that an
I invitation for bids will be released on May 21, 1970, for expanded
primary and excess flow treatment. This is a $17.3 million project.
This project is designed to alleviate the peak flow problems caused
by the District's combined sewer. This project is two-months and
21 days behind schedule.
V Design is under way for expanded secondary treatment capacity which
mt it is estimated will cost more than $46 million. This portion of the
project is ahead of the schedule adopted by the Conference.
A contract has been signed for a $27 million sludge processing
plant that will handle sludge disposal for the proposed expanded plant.
£ As Mr. Jackson reported at the third session of the Conference in
» 1969 the original design of the advanced waste treatment facility was
predicated on filling in of the Potomac Estuary. On December 15, 1969,
j the Secretary of the Interior advised the Corps of Engineers of the
Department's objection to this proposed destruction. Mr. Hickel's
position was based on the need for improved national management
_ practices for the estuaries and on apparent alternate ways of meeting
the District's waste treatment needs.
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Alternatives to Expansion at Blue Plains
There are four general alternatives open to the District in the
development of a wastewater treatment facility to fit their needs:
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(1) utilize the present plant site increasing the density of systems
B by employment of such techniques as the Linde process, tube clarifica-
tion, and stacking of components; (2) construction of a new regional
plant on the Anacostia by Washington Sanitary Suburban Commission (WSSC)
to relieve the load at Blue Plains, (3) expand onto other lands near
Blue Plains; or (4) some combination of these approaches.
The Federal Water Pollution Control Administration and the District
of Columbia Department of Sanitary Engineering have been engaged for
several years in a major effort to develop improved waste treatment
techniques which would provide very high level removal of oxygen
demanding materials and nutrients. A summary of the project is attached
fl as Appendix A of this report. In addition, the Federal Water Pollution
Control Administration has supported numerous advanced waste treatment
projects in other parts of the country. These projects have collectively
demonstrated a great many processes, chemical, physical, and biological,
which can be used in varying combinations to achieve the highest degree
fl| of waste treatment. In many cases, these processes are also expected
to reduce space requirements, reduce capital cost, and to provide
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higher levels of reliability.
Mr. Paul Freese, Assistant Director, Department of Sanitary
Engineering for the District of Columbia, has advised FWPCA that the
District has now developed preliminary designs for improvements and
expansion of the Blue Plains facility which would meet the water quality
goals as established by the Conferees, and which would avoid the need
for land filling in the Potomac Estuary.
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The Conferees, at their April 1969 meeting, identified the need
for further studies to determine the extent to which it might be
necessary to limit flows to the Blue Plains site. The table below
indicates the current and projected loads of the several interceptor
systems presently connected to the Blue Plains facility. Most of these
past connections have been made without significant engineering studies
of the treatment problems which might be encountered at the Blue Plains
facilities.
Projected Projected
Capacities at Flows from
Blue Plains QlGD)* Table 1** (MGD)I/ Difference
D. C. 135 136 1
1980 Virginia 18 32 14
Maryland 156 _16_4 9
309 332
D. C. 180 170 -10
2000 Virginia 65 130 65
Maryland 174 333 159
419 633
* Metcalf and Eddy report and information from D. C. Sanitary
Engineering Department.
** Potomac Conference Report.
( Projects based on unpublished Population Studies and Forecasts by
Hammer, Greene, Siler Associates (High Projection)
If projected increases in population and consequent higher flows
occur as predicted by Hammer, Greene, Siler Associates, the proposed
_ 419 MGD plant would soon be overloaded.
Construction of a new regional facility by the old WSSC near Peace
Cross on the Anacostia River offers an immediate opportunity to begin
the process of stabilizing the total future flows which must be managed
at the Blue Plains. WSSC operated a treatment plant at this location
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until about 15 years ago., The site is still owned by WSSC. The
l| WSSC five-year plans call for early construction of a 3O MGD interceptor
extending approximately from Peace Cross to Blue Plains. The WSSC has
p estimated that the new Anacostia pumping station and force main required
to handle flows in excess of the capacity of the existing interceptor
* will cost an estimated $19 million.
B The engineering and economic rationale behind this interceptor
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proposal must be carefully reviewed in terms of the very high levels
of treatment which must be provided for all wastes discharged in the
Potomac Estuarine System and the constraints on unlimited expansion of
the Blue Plains facility. The levels of treatment would in either case,
Blue Plains or Peace Cross, be extremely high, essentially total
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renovation of waste to drinking water quality, and there is no reason
to believe that the investment in the interceptor would effect the
significant savings in either capital or operating costs.
The availability of land is an even more critical issue. In
contrast to the Blue Plains situation, the WSSC property is in an
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industrial zone with reasonable opportunities for expansion without the
I consequences of massive environmental damage. The site of the
Anacostia-Peace Cross plant and photographs are shown in Figure 1 and
on exhibits here in the conference room,
The Anacostia sub-estuary is shallow with extremely poor circu-
lation characteristics. Under these circumstances, the estuary could
reasonably be expected to have very limited "assimilative capacity"
and to respond adversely to the introduction of substantial quantities of
nutrients. On the other hand, the introduction of substantial flow of
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clean water at the Peace Cross location could reasonably be expected
B to have a beneficial effect, Output of high quality water from the
Anacostia plant might also have value as a supplemental water source
P as, for example, make-up cooling water at the PEPCO-Benning Road
generating station. These latter potentials have not been explored,
although the Conferees, acting in accordance with Recommendation 4,
9 have established a task force to investigate opportunities for water
reuse in the Washington Metropolitan area.
Expansion of Piscataway
The WSSC Treatment Plant, located on Piscataway Bay, became operation-
al in early 1968. The plant has a design capacity of 5 MGD, and a BOD
reduction level of 90 percent. In April 1969, the Maryland State Depart-
» ment of Health approved operation of the plant at 8 MGD. This approval
was based on operating experience which indicated the plant could
operate at that level. The plant was initially designed to discharge
effluent to the mainstream of the Potomac River. Necessary con-
H struction permits could not be obtained, and effluent was accordingly
^ discharged directly to the head of the embayment.
Operation of the plant has been controversial, and residents have
objected frequently to bypassing, overloading, and allegedly poor
operations. The current plant does not provide nutrient removal. The
area served by the Piscataway Plant is experiencing a rapid population
_ growth and Includes many areas which are currently served by malfunc-
tioning septic tank systems. The Maryland Department of Health
on September 24, 1969, directed WSSC to proceed Immediately with
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plans for its enlargement to meet Immediate demands. The construction
schedule for the plant is as follows:
Preliminary Plans Final Commence Operational
Completed Plans Construction ____
3/1/70 3/1/71 7/1/71 1/1/73
It is anticipated that this expansion will provide the capacity needed
to serve the present population and anticipated growth to the year 1980.
Plans for the plant call for discharge to the head of Piscataway
Bay at the level of treatment called for by the Enforcement Conference.
However, the Maryland Department of Health has informed the Federal
Water Pollution Control Administration that phosphate removal will be
required in the initial plant design and will, therefore, be in advance
of the Conference requirements. WSSC has not yet decided on the nutrient
removal process to be adopted. High reliability features will be included
in the plant design to help assure that Piscataway Bay will not be
polluted by untreated or partially treated effluents.
As explained earlier, continuing FWPCA studies of the Potomac
Estuary have demonstrated that the Blue Plains Plant is the dominant
factor in determining water quality in the Potomac Estuary and that a
substantial improvement cannot be expected until Blue Plains improvements
are completed, and the plant can be fully operational.
Piscataway Advanced Waste Treatment Facility
This demonstration project to be located at the Piscataway waste
treatment plant became active in June 1969 when an original Federal Water
Pollution Control Administration grant of $1,650,000 was supplemented
by a grant of $750,000 to permit construction of a full-scale advanced
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treatment plant, utilizing techniques developed at Blue Plains. The
flj facility will employ two-stage "high lime" treatment with intermediate
recarbonation, dual-media gravity filters, stabilization and carbon
I adsorption with regeneration. The schedule calls for the design to be
completed in April 1970, bids to be let in June 1970, and construction
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to be completed by mid 1971.
Recommendations for "Fail-Safe" Sewerage Systems
The need for effective, fail-safe operation of municipal sewerage
systems (pumping stations) and treatment plants is receiving increased
technical attention. General steps which can be taken to achieve
reliability include:
--Auxiliary or alternate power sources to insure continuous
oper ability.
--Automatic alarms to alert plant personnel of operational mal-
functions such as untreated overflows and chlorination failure.
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--Sewer systems that will achieve total containment of wastes
The elimination of plant and pumping station bypasses.
_ --Holding ponds to provide detention of wastes in the event of
equipment malfunctions.
--Duplication of treatment process and pumping units.
--Adequate performance evaluations of all pollution control
facilities.
These are new, almost novel, concepts in the sanitary engineering
w field, although they are long established in the many industrial
and military areas. FWPCA engineers expect to work continually
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with the State and local agencies to provide reasonable
assurances that our treatment plant will work all of the time -
not just some of the time. For example, the FWPCA and the
Virginia State Water Control Board have recently recommended that
additions and revisions be made to Fairfax County's Westgate
and Pohick treatment facilities that will increase the reliability
of operation of those facilities.
An inspection of the new Pohick plant revealed that duplicate
power sources with automatic switching have been provided. However,
an overflow sewer was built into the system, and there was some question
regarding whether or not some critical elements of the electrical system
had been separated. The Federal Water Pollution Control Administration
recommended that consideration be given to the installation of a sluice-
gate in the overflow sewer, and the Virginia State Water Control Board
recommended that within 3O days the County of Fairfax provide a report
concerning the technical and economical feasibility of constructing a
holding pond to provide containment of raw sewage during emergencies
when overflows might otherwise result The Virginia State Water Control
Board also requested that complete information be supplied concerning
whether or not there is complete separation of critical elements of the
electrical system and that information be provided concerning power out-
age in the power substations.
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with the State and local agencies to provide reasonable
assurances that our treatment plant will work all of the time -
not just some of the time. For example, the FWPCA and the
Virginia State Water Control Board have recently recommended that
additions and revisions be made to Fairfax County's Westgate
and Pohick treatment facilities that will increase the reliability
of operation of those facilities.
I An inspection of the new Pohick plant revealed that duplicate power
sources with automatic switching have been provided. However, an
fl overflow sewer was built into the system, some critical elements of
the electrical system were not separated, and there was no backup for
some critical equipment components. We have recommended the installation
of a sluice-gate on the overflow, construction of a holding pond to
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provide 24-hour detention in the event of equipment malfunction, and
elimination of the overflow outfall to Pohick Creek.
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APPENDIX A
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Research and Development Projects
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FWPCA-DC Pilot Plant at Blue Plains
The FWPCA-DC Pilot Plant at Blue Plains is currently engaged in a research
plan consisting of five major components, as well as some supporting laboratory
scale activities. The major components are as follows:
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1. Conventional - tertiary treatment - This system consists of primary
H sedimentation, step aeration, secondary sedimentation, two-stage lime precipi-
_ tation with intermediate recarbonation, ammonia stripping, and filtration at
* an average flow of 100,000 gpd. Steady state start-up was 2/1/70 with a key
I decision on air stripping scheduled for 7/15/70 and a system program review
on 8/15/70 for this component as well as all of the others. Objectives are
| high degrees of removal of phosphorus and nitrogen and moderately high levels
_ of carbon following conventional secondary treatment. Advantages include more
proven systems with possibility of reclaiming lime.
2. Independent physical - chemical treatment - The 100,000 gpd system
consists of two-stage lime precipitation with intermediate recarbonation,
filtration, pH control (water stabilization), selective, or exchange (for
ammonia removal), carbon adsorption, and laboratory scale ozone oxidation.
Start-up was 2/11/70. Objectives are complete waste treatment from raw sewage
| through high degrees of removal of phosphorus, nitrogen, and carbon. Advantages
M include elimination of biological processes, reduced space requirements, and
possibility of reclaiming lime.
3. Mineral addition conventional - tertiary treatment - System follows
conventional primary treatment and consists of aeration with mineral addition
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(alum or iron salts), secondary sedimentation, and filtration or alternately
carbon adsorption at pilot flows of 2000 gpd as well as laboratory scale.
Steady state start-up is scheduled for 5/1/70. Objectives are equivalent de-
grees of removal of phosphorus and carbon with less capital facilities than
I conventional-tertiary treatment. Advantages include reduced cost and space
im for phosphorus and carbon removal.
4. Solids handling and recalcination - The system consists of a thickener,
vacuum filter alternately with a solid bowl centrifuge (available 7/70), and
a six hearth furnace and will alternate between sludges from the conventional -
tertiary and the independent physical - chemical treatment processes. Start-
up is to be 3/15/70. Objectives are to develop and evaluate methods of handling
and reusing chemicals resulting from advanced waste treatment processes.
5. Pure oxygen process - System with average flow of 100,000 gpd follows
| D.C. conventional primary treatment and consists of accelerated activated
_ sludge using pure oxygen followed by clarification for carbonaceous BOD removal
followed by second stage activated sludge using pure oxygen followed by
clarification for nitrification. The flow is then to be denitrified using
other biological methods or carbon columns followed by lime addition with
clarification and/or filtration for phosphorus removal and then carbon columns
_ for polishing and refactory organic removal,, Initial start-up will be 4/1/70
* with nitrification - denitrification phase commencing approximately six months
later. Objectives are to reduce size of treatment units for carbonaceous BOD
and nitrogen removal, streamline lime precipitation treatment by reducing
chemical dosage and sludge production and eliminate clarifier in solids removal
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stage, and achieve high degree of carbon removal. Advantages include reduced
space requirements, reduced chemicals and sludge production, makes nitrifica-
tion - denitrification practical for large metropolitan treatment plants
such as Blue Plains.
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The laboratory scale studies include ozone oxidation as a replacement for
carbon column effluent polishing and break point chlorination for nitrogen
removal .
Combined Sewer Systems - D.C.
H In July, the Federal Water Pollution Control Administration approved a contract
M with the Engineering Consultant Firm, Roy F. Weston, to help define the problems
of combined sewer discharges within the District of Columbia; investigate the
feasibility of high rate filtration for the treatment of combined sewer over-
flows; and to study alternative methods of solution to the problem.
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The project is nearing completion and preliminary reports are being prepared.
A report will be presented at our regular progress meeting in May.
Kinqman Lake Recreational Area
On October 8, 1969, Secretary of the Interior, Walter J. Hickel, announced
| combining the features of storm water treatment and recreational development
_ in the Kingman Lake area of the Anacostia River. The project, as presently
conceived, will treat overflow from the Northeast boundary combined sewer
I and make-up water from the Anacostia. The plant output will be discharged
into a series of small lakes. The first lake following treatment will contain
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aesthetically attractive aerators and can be used for fishing and boating.
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The second lake will be utilized for bathing.
The feasibility study is approximately 50 percent complete with anticipated
completion date of June 1970. Aerial photography and soil borings are
complete. Topographical mapping and feasibility studies are underway.
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The realization of the total project objectives will require the active
cooperation of the many local and Federal governmental agencies.
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