c/EFft
                     United States
                     Environmental Protection
                     Agency
                                    Municipal Environmental
                                    Research Laboratory
                                    Cincinnati OH 45268
                                                                                         "
                     Research and Development
                                   EPA-600/S2-84-061 Apr. 1984
Project Summary
Priority Pollutants  in the Cedar
Creek  Reclamation-Recharge
Facilities
                    Thomas D. Brisbin, Shin H. Ahn, Robert I. Foster, Stanley A. Labunski, and
                    James A.  Oliva
                      The Cedar Creek Wastewater Recla-
                    mation Plant in Nassau County, NY, is a
                    0.24 mVs (5.5 mgd) advanced waste-
                    water treatment (AWT) plant designed
                    to produce a high quality effluent
                    suitable for groundwater recharge. The
                    Reclamation Plant was constructed as a
                    demonstration project under a  U.S.
                    Environmental Protection Agency (EPA)
                    grant by additions and modifications
                    to the main 1.96 mVs (45 mgd) Cedar
                    Creek Water Pollution Control Plant.
                    Operation of the Reclamation Plant
                    began in April 1980, and groundwater
                    recharge operations began in  October
                    1982.
                      This research project was  initiated
                    with the overall objective of providing
                    preliminary data on the presence of
                    priority pollutants in the Cedar Creek
                    Wastewater Reclamation - Recharge
                    Facilities. The results indicate that 72
                    priority pollutants were identified in the
                    influent and that significant removals,
                    up to 99% of some individual compounds,
                    were achieved by the plant processes.
                    The data also indicate that the concen-
                    tration of trihalomethanes increases
                    during both the treatment and recharge
                    operations.
                      This Project Summary was developed
                    by EPA's Municipal Environmental
                    Research Laboratory, Cincinnati, Ohio,
                    to announce key findings of the research
                    project that is fully documented in a
                    separate report of the same title (see
                    Project Report ordering information at
                    back).

                    Introduction
                      To  retard the contamination of the
                    Upper Glacial Aquifer and to protect the
                    remaining aquifers that provide Nassau
                                   and Suffolk Counties with their sole
                                   source of potable water supply, Nassau
                                   County embarked upon a sewer program
                                   in 1950 that, when completed in 1985,
                                   will result in 85% of the county being
                                   sewered.  As part of  this program, an
                                   Environmental Impact Statement (EIS) on
                                   Wastewater Treatment Facilities Con-
                                   struction Grants for Nassau and Suffolk
                                   Counties, New York, was completed in
                                   1972. Adverse environmental effects
                                   associated with the sewer program and
                                   subsequent discharge of the  treated
                                   sewage effluent into Long Island Sound,
                                   the South Shore Bays, and the Atlantic
                                   Ocean could cause groundwater levels to
                                   decline unless the decline is counterbal-
                                   anced by groundwater recharge. The
                                   declining groundwater levels could result
                                   in: (1) decreased groundwater inflow to
                                   streams, (2) declining levels of "water
                                   table" lakes, (3) decreased subsurface
                                   groundwater outflow to the  bays and
                                   Long  Island Sound, and (4) salt-water
                                   intrusion into the groundwater aquifers.
                                   These declining groundwater levels could
                                   cause increased salinity in some of Long
                                   Island's estuaries and bays and, thus,
                                   alter the ecosystems of these saline
                                   water bodies.
                                     As part of the EIS conclusions, it was
                                   determined that: (1) the construction of
                                   collection systems and effective waste-
                                   water treatment facilities are essential to
                                   protect the public water supply of Long
                                   Island, and (2) as soon as the technology is
                                   available, it would be advantageous for
                                   Long Island to implement groundwater
                                   recharge for the ultimate protection of its
                                   water  supply. A feasibility study  on
                                   advanced  wastewater treatment and
                                   groundwater recharge was completed
                                   under an EPA grant in August 1973. The

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results of the feasibility study formed the
basis for the design and construction of
the 0.24 mVs (5.5 mgd) Cedar Creek
Wastewater Reclamation  - Recharge
Facilities, which were placed in operation
in April 1980.
  The specific objectives of the research
project reported herein were to: (1) deter-
mine individual treatment processes' and
overall reclamation plant performance for
the removal of  priority pollutants, (2)
determine the transformation or genera-
tion of priority pollutants by the treatment
processes, and (3) determine the priority
pollutants present in the groundwater be-
fore and after recharge. It was acknow-
ledged during the planning  period  that
the number of samples would be minimal
and the results would be indicative rather
than  deterministic. This approach  was
acceptable because the facility was in its
initial stages of operation and the analyti-
cal results would  indicate potential prob-
      lems rather than provide statistical eval-
      uations of performance and reliability.


      Description of Reclamation
      Plant and Recharge Facilities
        The Reclamation Plant is an AWT plant
      consisting of grit removal,  chemically
      aided primary clarification,  suspended
      growth nitrification/dentification, chemi-
      cally aided sedimentation, dual-media
      filtration, carbon adsorption and chlorine
      disinfection (see Figure 1).
        The basic approach taken for design of
      the Reclamation Plant was  to  combine
      incorporation of the best available techno-
      logy in 1973 with the maximum use of
      existing  Cedar Creek Water  Pollution
      Control  Plant facilities. Modifications to
      existing facilities included the following:
      (1) flocculation chambers were constructed
      by installing a bulkhead, and horizontal
      shaft, slow speed, turbine mixers in the
                              influent channel to two of the six existing
                              primary tanks;  (2) 2 of the 12 existing
                              aeration tanks and  1 of the 8  final
                              clarifiers were used for combined carbon
                              oxidation-nitrification; (3) 2 aeration
                              tanks and a final  clarifier were used for
                              denitrificaiton;  (4) 2 aeration tanks and
                              the existing chlorine handling equipment
                              were used for disinfection; and  (5)
                              existing solids  handling facilities  were
                              utilized. New processes and equipment
                              included: (1) rapid-mix basin and chemical
                              handling systems for lime slaking,  ferric
                              chloride, polymer, and alum; (2) gravity
                              flow, mixed-media filters; (3) gravity flow,
                              granular activated carbon adsorbers; (4)
                              carbon  regeneration furnace; and  (5)
                              methanol feed system.

                                The effluent from  the Reclamation
                              Plant is transported 10.1 km northwest of
                              the plant, via a 61.0-cm diameter (24 in.)
                              concrete-lined steel pipe, to the Cedar
Raw
Wastewater
r
Backwash
Waste
To Cedar Creek
Water Pollution
Control Plant

Grit
Removal
Waste
CCWF
#7

to ^ \
Lime
Mixing







% Si
*~
Sludge
CP*
imple Point
Primary
Sedimentation


k.

                         Alum and
                          Polymer
                              Methanol
             Sedimentation
              (Final Tank
                No. 7)
  Post
Aeration
Denitrification
Sedimentation
 (Final Tank
   No. 5)
  Carbon
 Oxidation-
Nitrification
                                                                                  Sludge
                                                                                                 Waste to CCWPCP
                                                        Chlorine
                                                           i
                                    I
Chlorination
#5



Effluent
Storage
fc Ove
WCCWP(
I
       Backwashes
                                                                     \Transmission Line
                                                                          (10.1 km)
                                                                                                  To Cedar Creek
                                                                                                 Recharge Facilities
Figure 1.    Cedar Creek wastewater reclamation plant.

                                    2

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Creek Recharge Facilities in East Meadow,
New York.
  The Recharge Facilities  consist  of
recharge basins,  injection wells, a
storage reservoir, and associated equip-
ment required to recharge water from the
Reclamation Plant. Water to be recharged
is received into a 144 m3 central reservoir
from where  it is distributed to the wells
and basins. The reservoir provides 0.17-
hr detention at the design flow  rate of
0.24 m3/s. Pumping facilities are provided
in the Operations Building, along with a
sodium hypochloritefeed system that can
be used, if required, to control biological
activity in  the recharge basins. Flow
rates, line pressures, and recharge water
quality are monitored and controlled at
this building. A schematic diagram of the
Recharge Facilities is presented in Figure
2.
Approach
  The sampling and analysis program for
priority pollutants was divided into three
                                Well "E"
 Well "D
phases. The first phase, conducted during
April,  May, and June, 1981, was to
determine the overall performance of the
Reclamation Plant.  The second  phase,
conducted'during August, September,
and October,  1982,  was designed to
investigate the performances of individual
Reclamation Plant processes. The third
phase  involved  analyzing samples taken
from monitoring wells at  the recharge
facility site. These samples were collected
in May and October, 1982, to determine
the effect of recharge on groundwater
below the site. Over the project period, 37
samples were  collected. The sample
locations are indicated schematically in
Figures 1 and 2.

  Plant samples were 24-hour composites
started at intervals that compensated for
the  detention  times in  the various
treatment units.  This was done  to
approximate the same water mass at
each location. Composite samples were
collected with the use of special, custom-
made, glass/Teflon composite samplers
designed to minimize loss or contamina-
tion of trace  organic  substances. The
samplers were operated at constant flow
rates, paral lei ing the constant flow rate of
the plant.
  Observation wells sampled during the
third phase of this program were selected
on  the basis  of proximity to individual
recharge facilities and the direction and
depth of the recharged water flow. Four
observation wells were not sampled after
recharge because the recharged waste-
water  had  not yet reached these wells,
according to conductivity tests performed
by the U.S. Geological Survey. Observa-
tion wells were grab sampled.

  Samples  were analyzed for a total of
128 priority pollutants (asbestos  was
excluded):  31 volatile  organics, 47
base/neutral-extractable and 11 acid-
extractable organics, 25 pesticides/PCB's,
13  metals,  and total cyanide. Analyses
were also performed to determine  con-
                                                                                                   From Cedar Creek
                                                                                                     Wastewater
                                                                                                   Reclamation Plant
                         i Sample Point(sj
Figure 2.    Cedar Creek wastewater recharge facilities.

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centrations of nonpriority organic pollu-
tants.

Results

Overall Plant Performance
  The Phase I investigation identified the
constituents present in the effluent to be
used for groundwater recharge  and
evaluated the  overall removal of priority
pollutants from the wastewater facility.
  Seventy-two priority  pollutants were
identified in the raw wastewater: 18
volatile, 23 base/neutral-extractable, and
6 acid-extractable organics; 15 chlorinated
hydrocarbons; and  10  heavy metals.
Thirty-five nonpriority pollutants were
also identified: 2  volatile organics, 28
extractable organics, 1  pesticide, and 4
heavy metals.
  The analysis of overall plant perform-
ance indicated that the Reclamation Plant
provides the following removals of pri-
ority pollutants, based on total mass  of
identified compounds:
  Volatile organics
  Extractable organics
  Pesticides/PCB's
  Metals
85%
80%
47%
64%
  Some of the volatile compounds iden-
tified  in  the effluent,  such  as tri-
bromomethane,  dibromochloromethane,
bromodichloromethane, and dichloro-
fluoromethane,  appear to be  formed
as a result of chlorination.
Unit Process Performance
  The data collected  in Phase II of the
project indicates that biological treatment
and post aeration are the major processes
responsible  for removal  of volatile
organics. Chemically aided  primary
clarification  and biological treatment
with  alum and polymer addition are
almost equally important for the removal
of metals. Findings based on the total
pollutant mass at each sampling location
over the three sampling events indicate
that  41 % of  the volatile organics were
removed through primary clarification and
that  concentrations of these materials
were below detection limits after biological
treatment. Fifty percent  of the heavy
metals were  removed through primary
clarification,  and biological treatment
increased the removal to 93%.  Further
metals removal by  filtration/carbon
adsorption appears to be negligible.
  Six volatile organics were detected in
the carbon adsorber effluent during the
three Phase  II sampling  events.  After
chlorination, however, 10 volatile organics
were detected in the chlorinated effluent.
Apparently several volatile organics—
most notably, trihalomethanes(THM's)—
were formed during chlorination. These
compounds were, in order of decreasing
concentration: bromoform, dibromochloro-
methane, chloroform, and bromodichloro-
methane.
  The concentrations of bromoform and
dibromochloromethane were, in some
                   cases, higher than  their maximum
                   discharge concentrations of 50 /ug/L, as
                   stipulated in the facility's State Pollutant
                   Discharge  Elimination System (SPDES)
                   permit. Furthermore, during two of the
                   sampling events, total trihalomethane
                   (TTHM) concentrations were higher than
                   the maximum  contaminant level of 100
                   /ug/L specified in the U.S. EPA's Interim
                   Drinking Water Standards.
                     The relationships between the forma-
                   tion  of THM's,  COD,  chlorine  dose,
                   residual chlorine, and pH were investigated
                   using the priority pollutant  and plant
                   operating data. The data suggest a
                   combined effect of chlorine and organic
                   precursor  presence,  as measured  by
                   COD, on the formation of THM's.

                   Effect of Recharge
                     During the Phase III testing program,
                   samples were collected from the six
                   monitoring wells before beginning the
                   recharge operations to  determine the
                   baseline concentrations of priority pollu-
                   tants  in the groundwater.  Bis (2-ethyl-
                   hexyl)  phthalate and seven volatile
                   organics were detected in monitoring
                   wells before recharge.  These data are
                   shown in Table 1.
                     Although THM's were  not detected in
                   any  of the monitoring wells before
                   recharge, they were detected at significant
                   levels  after  recharge. TTHM concentra-
                   tions for the two well samples taken after
                   recharge were 256 and 258 /ug/L. These
Table 1.    Effect of Recharge on Priority Pollutant Concentrations in Monitoring Wells at the Cedar Creek Recharge Facilities (fig/LJ

                                     Well4B         WellD6        Well 11B        Well 11C        Well12A        Well 12B
Compound
 Before After  %  Before After  %  Before After  %  Before After %  Before  After  %  Before After  %
  Rech. Rech. Chg. ftech.  Rech. Chg,  Rech. Rech. Chg. Rech,  Rech. Chg. Rech.  Rech. Chg.  Rech. Rech. Chg.
 Volatile Organics

 Bromodichloromethane
 Bromoform
 Chloroform
 Cis/Trans-1,2-
  dichloroethene
 Dibromochloromethane
 1,1 Dichloroethane
 1,1 Dichloroethene
 Methylene Chloride
 Tetrachloroethene
 1,1,1- Trichloroethane
 Trichloroethene
 Jrichlorofluoromethane

 Base/Neutral Extractables

 Bis (2-ethylhexy/j phthalate

 Metals

 Copper
 Lead
 Zinc
  BDL
  BDL
  BDL
  BDL
    6
  BDL
  BDL
   20
    9
   63
   20
    3
   20
       BDL
       BDL
       BDL

       230
       BDL
       BDL

       BDL
       600
         *

        55
                  33
       BDL
       BDL
       BDL
BDL
BDL
BDL

BDL
BDL
 43
 10
BDL
  8
 49
  #

BDL
                                BDL
 80
BDL
BDL
BDL
BDL
BDL
BDL
BDL
19
*
BDL
*
50
BDL
*
34
124
*
BDL
98
BDL
BDL
BDL
BDL
BDL
BDL
BDL
(-1
I-)


(-1
>47



>eo


BDL
BDL
BDL
6
BDL
34
8
BDL
*
46
55
*
                             BDL
                             BDL
                             BDL
      33  (•)
      110  (-)
                                              BDL  BDL
                                                             BDL
 30   BDL  >33  BDL
BDL  BDL       BDL
 70   BDL  >71  20
                             BDL  BDL
                             BDL   IIS
                              "   BDL
                             BDL  BDL
                             BDL
                             BDL
                              5
                                  BDL
                              *   BDL
                                                                           BDL   BDL
BDL  BDL
BDL  BDL
BDL  BDL
 BDL: Below detection limit
 *: Detected, but /ess than a quantification limit of 10/jg/L
 (-)•' Pollutant concentration in the wells is higher after recharge than before recharge.

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  vels  are  higher  than the maximum
 jntaminant level of 100 ug/L specified
in EPA's Interim Drinking Water Standards.
They are also at or above levels measured
in the Reclamation  Plant Effluent.
  An analysis of data at various points
along the recharge path (effluent storage,
transmission, percolation in the soil)
indicates that as detention time increases,
the concentrations of THM'salso increase.

Conclusions
  • The concentrations of the THM's
    bromoform,  chloroform, and dibro-
    mochloromethane appear to increase
    in the plant effluent after chlorina-
    tion.
  • It is difficult to drawfirm conclusions
    regarding unit  process performance
    for the removals of priority pollutants
    because the  number of samples
    analyzed was  small  and  many
    compounds  were below detection
    levels.  In a few cases,  pollutant
    concentrations in the effluent were
    found to be  higher than their
    corresponding concentrations in the
    influent, which resulted in large
    variations in removal efficiencies.
  • The combined effect of  high COD
    concentration and high chlorine
    dose appears to  be significant with
    respect to THM formation.
  • Observation  well  samples  taken
    after recharge demonstrate an
    increase in TTHM concentrations in
    the aquifer.  Residual  chlorine,
    combined with organic carbon in the
    recharge water and long detention
    times, appear to be determining
    factors.

Recommendations
  • Evaluate the formation of THM's in
    the plant and recharge operations.
    As part of this evaluation:
  (a)  optimize chlorine dose to  reduce
      residual chlorine levels;
   (b) investigate the use of alternative
      disinfectants,  such as chlorine
      dioxide or ozone;
   (c) identify and  reduce THM  precur-
      sors; and
   (d) increase the  organics removal
      efficiency of  the carbon adsorbers
      by increased carbon regeneration
      frequency or  increased contact
      time.
  • Use more sensitive analytical proto-
     cols than standard EPA methods for
     future investigations of unit process
     removals of priority pollutants.
  The  full report was submitted in
fulfillment of Grant  No. CR804654 by the
County of Nassau, NY, under the sponsor-
ship of U.S.  Environmental Protection
Agency.
  Thomas D. Brisbin. Shin H. Ahn. Robert I. Foster, and Stanley A. Labunskiare with
    PRO Consoer Townsend Inc., Chicago, IL  60601; James A.  Oliva is with
    Nassau County, NY 11793.
  John N. English is the EPA Project Officer (see below).
  The complete report, entitled "Priority Pollutants in the Cedar Creek Wastewater
    Reclamation-Recharge Facilities," (Order No. PB 84-159 904; Cost: $11.50,
    subject to change) will be available only from:
          National Technical Information Service
          5285 Port Royal Road
          Springfield,  VA 22161
          Telephone: 703-487-4650
  The EPA Project Officer can be contacted at:
          Municipal Environmental Research Laboratory
          U.S. Environmental Protection Agency
          Cincinnati, OH 45268

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United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
                                                                                             4 U.S. GOVERNMENT PRINTING OFFICE: 1984-759-102/

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