EVALUATION OF WASTE
LOAD ALLOCATIONS
PATUXENT RIVER BASIN
February 14, 1974
Thomas H. Pheiffer
AIR & WATER PROGRAMS
ANNAPOLIS FIELD OFFICE
Environmental Protection Agency
Region III
-------
60OR740O3
EVALUATION OF WASTE
LOAD ALLOCATIONS
PATUXENT RIVER BASIN -
February 14, 1974
Thomas H. Pheiffer
AIR & WATER PROGRAMS
ANNAPOLIS FIELD OFFICE
Environmental Protection Agency
Region III
-------
During the 1973 summer sampling season, the Annapolis Field
Office collected water quality data in the Patuxent River Basin for
the purpose of calibrating and validating math models for the Basin.
Model application was completed in November, 1973. Utilizing the
1973 sampling data, the models have successfully predicted, in both
the free-flowing Patuxent and the Little Patuxent Rivers, dissolved
oxygen response to changes in volume and/or concentration of point
sources of carbonaceous and nitrogenous BOD loadings under various
stream flow conditions and temperatures. Documentation of the
modelling verification procedure will be presented in a forthcoming
Technical Report Number 58, "Application of Auto-Qual Modelling
System to the Patuxent River Basin".
Mr. Charles Hall, Maryland Environmental Service (MES), is
completing the final draft of the Section 303(e) Patuxent River Basin
Plan. In the plan, the MES has recommended the adoption of a uniform
policy on effluent standards for wastewater treatment discharges into
the Patuxent River Basin. A copy of the uniform treatment policy is
attached.
Mr. Thomas Pheiffer has made avail able--to Mr, Ha-11-the EPA-math .
models for the Patuxent River Basin. The models were used to
determine the adequacy of the recommended effluent levels and/or
loadings for meeting water quality standards for the planning years
-------
1980 and 2000. The 1980 and 2000 projected wastewater flows were
tested utilizing the effluent restraints proposed by MES.
In assessing the load allocations of MES, the following criteria
were used in making all the model runs. The 7 day - 10 year low
flows -- obtained from U.S.G.S. records -- were 15.0 cfs for the
free-flowing mainstem of the Patuxent River (specified release from
Rocky Gorge Dam) and 11.8 cfs for the Little Patuxent River at
Savage, Maryland. Incremental flows from minor tributaries were
allowed for the Little Patuxent River. A constant stream temperature
of 28°C was used. At 28°C dissolved oxygen saturation is 7.9 mg/1
for background stream concentrations. Background stream levels of
ultimate carbonaceous oxygen demand (CBOD) and ultimate nitrogenous
oxygen demand (NBOD) were specified at 2.0 and 3.0 mg/1, respectively.
Model runs were made using the 1980 and 2000 projected waste-
water flows for both a with and without regional treatment scheme.
Figures 1-8 show the wastewater loadings, the effluent concentrations,
and the resultant stream profiles of dissolved oxygen. Of the 3
mg/1 total nitrogen, only 1 mg/1 was assumed to be oxidizable. A
dissolved oxygen concentration_o.f Ajng/l_was..assignecL.to...al.l....tr.e.atr_.. .
ment plant effluents except for the Maryland City and Parkway plants
where a 6.0 mg/1 dissolved oxygen level was specified because of the
low-flow stream conditions resulting from minimum releases from
-------
Rocky Gorge Dam during the summer months.
Figures 1-8 clearly show that water quality standards will be
met and maintained for the planning periods 1980 and 2000 with the
implementation of the uniform effluent standards recommended by the
State of Maryland. Maryland will opt for regional treatment because
of cost effectiveness. The loadings from regional treatment are
presented below.
S.T.P.
Little Pat.
Reg. PH.
Maryland
City (P.R.)
Parkway
(P.R.)
Central
Patuxent
(P.R.)
Year
1980
2000
1980
2000
1980
2000
1980
2000
Flow
m3/day
59,93~4
119,869
10,274
15,901
24,218
55,042
29,845
56,265
BOD 5
Kg/ day
660.6
1,201.3
103.0
159.4
242.7
551.6
299.1
563.9
SS
Kg/day
660.6
1,201.3
103.0
159.4
242.7
551.6
299.1
563.9
Tot. N
Kg/day
180.2
360.4
30.9
47.8
72.8
165.5
89.7
169.2
Tot. P
Kg/day
480.5
961.0
82.4
127.5
194.2
441.3
149.5
451.1
-------
In order to buttress the need for high degrees of treatment for
expanded wastewater flows in the Patuxent River Basin, an evaluation
was made of the adequacy of existing treatment to meet water quality
standards during the 7 day - 10 year low-flow condition. Figure 9
shows that with secondary treatment and no nitrogen removal water
quality standards are violated in the mainstem of the Patuxent during
the critical low-flow (15.0 cfs). The Parkway Wastewater Treatment
Plant is currently being expanded to 7.5 mgd (10.2 cfs). When the
enlarged Parkway Plant goes on line this spring, it will have
nitrification and high BOD removal. Figure 10 shows that with an
effluent concentration 8 mg/1 BOD5 and 2 mg/1 of oxidizable nitrogen
standards can be met in the mainstem of the Patuxent River.
For the Little Patuxent River, secondary treatment is not adequate
to meet standards for current wastewater volumes during the critical
low-flow (11.8 cfs). Even with high BOD removal (10 mg/1 BOD5
effluent) standards are contravened (Figure 11). High BOD removal
at all plants together with nitrification at the Savage Wastewater
Treatment Plant could result in standards compliance at the current
wastewater volumes-(Figure 12)
It is important to note that the above evaluation was based
solely on current wastewater volumes. Although nitrification at the
Parkway Plant appears adequate to meet standards in the mainstem of the
-------
Patuxent, any expansion of other plants or the addition of a regional
facility would necessitate nitrogen control for the expanded
wastewater flows. For example, should the Maryland City Plant,
located immediately upstream of the Parkway Plant, be expanded to 10.2
cfs in 1980 and 18.0 cfs in 2000, nitrogen control would have to be
included at this facility.
There is one final note. It is fairly safe to assume that
denitrification or control of the oxidizable nitrogen would protect
dissolved oxygen standards in the free-flowing Patuxent River and the
Little Patuxent River throughout the timeframe of the 303(e)
Patuxent River Basin Plan. The governing factor for total nitrogen
control (3 mg/1) is to maintain a biological balance in the estuary
by limiting the amount of nitrate nitrogen discharged from point
sources in the Basin.
-------
DEPARTMENT OF HEALTH AND MENTAL HYGIENE
Neil Sofcmon, M.D.. Ph.D., Secretory
ENVIRONMENTAL HEALTH ADMINISTRATION
6!0 N. HOWARD STREET o BALTIMORE, MARYLAND 212Q1 a Area Cods 301
333-
POLICY ON EFFLUEiT ST/illDARDS FOR
WASTEWATEa TREATMH1T DISCILJRGS5 BiTO SURFACE WATERS
IN THS'PATUXEMT Rr/ER . EftSIN
Effective June 15, 1973
new treatment plants of any capacity and all existing plants which
will be modified to increase capacity to 1.0 rcgd or more that have not had
a discharge approval from the Environmental Health Administration to the
effective date of this policy, will immediately design to meet the follovrLng
ininircum effluent requirements:
EOD5
Suspended Solids
Not to exceed 10 mgA
Not to exceed 10 mg/1
6.0 to 8,5
Dissolved Oxygen "
Above Baltiinore-'vfashington, .
Expressway- :Not--le&sthan-c^0-rag-/l-
Eelov Baltimore-Washington
Expressv?ay Not less' than k.O rcg/1
Phosphorus Net to exceed 8 ng/1 as P
Kitrogen (TKK + M02 + ^03) Not to exceed 3 ng/l as It
(Nitrogen removal on a seasonal basis as determined by
assessment of Basin conditions)
All. existing plants over 1.0 mgd including'those that have a discharge
approval from the Environmental Health Administration rcust produce effluent
of the above quality by July 1, 1978.
-------
of less CAf4.ci.ty $h*l\- be
1.0 Mgd.
All ei-.isting plants of less than 1.0 mgd will immediately design to
pi-oduce the folio-wing minir;Uir. effluent requirements. This effluent quality
must bs met by units which are to be in operation en July 1, 1975 J ~"
1-Tot to exceed 10 mg/1
.Not to exceed 10 mg/1
6.0 to 8.5
EQD5
Suscended Solids
PH
Dissolved 0>^gen
Above Baltimore-Washington
E>q:ress^-ay Kot less than 600 mg/1
Below EaltiTnore-Washington
Ejcpress'.-;ay Not less than Ij.O mg/3.
Addition of facilities to accomplish -nutrient removal vfill be required
if assessnent of the treatment plant contribution to the algal problem
determines it to be significant.
/6/7
------- -.",-i'.tn^'4- -i "-i-
-------
hitl-irn i i^i^i i i -; i ^ _jj: k -|i_;':1J_: i : ;' r;j_
t':-:;1^:;!::-]1:;;!:!':!!^1:-::'!-^-'
"''.'.!!:' "! : ' '.( ! '.: ' i
rVrV'-lv'i '37'Tnr'i ;rt"!~rrrTrr
'K 5.0 -
i-r'-M^I.T^-?P
! r' ! I ! ; 7 : i ' : 'I ! '
co.o
70-0
15.O
§0.0
FIGURE- 2.
-------
rt-ii'/i-riH- -'t.'f
Z&F& -tftf
T/-!-|Tr-'r|-' -i-
^rl:;^Tt;.rf:TJ-f.r:.-'1^T..pqj
-,r ...,.;-,.I-...... ,.i ..,., i.,.., i^..!.,..!.^,.^
50.0
-------
ffiprop
Trr-h-l-ir -H-- -HT
ri:;:j:|:pjTJ.~u:in';±r 3-ft
;;.:.£ ..;.i.! ! ,-,-, --..>. ^i-,..;-
;.;,;.!. ..i-|..t .Li-i-llUjX')^.
.;.;T|..:-U4 ;..,;-].)..:.U-kl-^-l-r.rl-r-
wm riiiwfe
.--r-F~r;-f ''. n:-:- ;' I'-:
E A-
-------
(S)
o
LU
2
UU
-
Q
O
o
1
!- ;Ti ii:!iT!i i!Ti!ini!f;
' I' ' - ' ;
'i j I,': ' ;;.;;]; i- .' ;
T ".' : lTi*]!l "''i-iT7' '! !T' '.'.'''">.
.';*'!;;. r l^;1! j ;.'!!.' i!'; '.! ; '.'.i :.ir. '.i.j
.. .. . .. .. ..
r :; |.: iTrti.r..!r:.Trr;Trr-|f-^: r.; ir; rrwit"; rll.-.! 'rr
;:!'i]TrTTlI;""nT:' rTflTIHI^^Fr??]: aT|T|S]jT
J ri ! ' i ,-. . 1-. ,.l ,- r-,...,..,.,., r,.rtl ft ,.,.l~. r.
. . ( i i-i. r i . i I . ,.| i p-i- . I f-.-i i-i-i .(!-. . I..-T,
-
....(.,.._ j..,.;,.:,;.. ,. .. ,, , ;TW.J.J,,.,^-I.| j_; .T.^ ...^ ;, jj.,.^^.^...^
iTJiliiliMiiiiiiiSi&SH-i'iw^^^
5.0-
4.0
3.0
2.0
1.0
"G.O
7 8 9 10 11 12 13 14 -15 16 17 13
^i /I?P
-------
.1
°
o
co d
aJ
< < p
16.0
15.0
14.0
13.0
12.0
11.0
10.0
g 9.0
o 8.0
11
t
I 7.Q
S
g'6.b
o
5.0
4.0
3.0
2.0
1.0
"C.O
Siifeii^j^ :.
Iliii^HnFiiii^iilri^
WESfflBS^ ;=I: iT;'= ' i!;
:f!^Uri.i;i?iqv
Ifiilf
i$.
3±
! |1 J
:;!..!,
]'\i":
IBIS
~^-j-Tl-'"M J:.! rj^f ' J
i';"'!:."!1.:;;.^^;
."):.; i:';jiir.f.L.'.:'-i;
ilSSlli
ii^li^ipfifri
^jSPffi
iryiiriiHii-HilJT*.:'!''
nntti.fi
Wii'if-i
-!;^;-;4!llHi!^f;-;iNiiitiHil^^
i|jiH!jiijj|!ji{j^||;;i!];!;!p^l!|!ii|^
Li-I
3 45
7 8 9 10 11 12 13 14 15 16 17 IS
-------
co
o
o
GO
-rf C\
H o!
Ci
oo
,1
r-,-
~
CL
7
I / . U
16.0 .
15.0 -
14.0 -
13.0 .
12.0 .
11.0 .
. 10.0 .
"O'.O
-
. . .. . .. . . . ...
;iI:!:[;i:li:;Ti;;'!'!:^!i::^|;;:;'ii;.^nlu^i^ll;1^
-r-11'!-
:j!Jiyy^i;;i;^;!^-i!^
'"" '
,.,-.,,:,, . , . ..,.,, jj_i_^! * " ; f ' l^_^_' ' ' " " ^T _j - - i- » r_._ t
W In r;:p i-i I r: M ,.i-.:{r;.i.r!i;::; I: ;^f.;.!J l .lit! IIr
- ..,...-.- --- - - - ' ''
iijjiliiiniiiiiVIiiil.iiiJHiiii-^ii^liJu.iwjii'1 :)!!;: ij.;.;j|iiiin}- jf!:1 i!;i!;;rl!iT:i:T;-K:
£i ;';;.! ;lj;i I!.: ::;!':!' i:::-i.!n'i"|.j:!':; ii'ii; I:i;:!^:;; Mi-::iH: I'lijTUi- i'iiiLii; \^\\]\\\ ;'.i:i:li i;l; .;
.:;:::;:::;:...!,:.:; ;;i. i:::: ;;..;,::; ;:;;:::;:; :;;:;;!;.; :i!',!,-i.: |.;rn.;,'ir Jl;;!;!:; ;:;M::i! h
:;::!:.:!:: j.:,np::i :;:!: Mi ;.::.i i;:;;ii!! Mi ;,'!;: :::.;;..;(; ;!!:i!.::^;;.:!:!i;:.!i:;ii.:::, ;
_
h" '
8 9 10 11 12 13 14 15 16 17 18
-------
r v"
c
n
I / . U _.
16.0
15.0
14.0
13.0
12.0
11.0
. 10.0
1 9.0
i 8.0
ii
i
I 7-°
|-6.0
C_5 '
5.0
4.0
3.0
2.0
1.0
%>a.o
-- . ;. - ..; ..
m3mm)m^!^:k^
, ;ij .. i .),.., . ._ ^;,i j ^'T|_-_^.J.I ^ 1.;;.^.f I '.'.J-Lj^'l'VJ.;. -'.1" I-'.'ii.^^i.'J-lj^.U.
;;.;; ;.:~;.i.ji:i:';-] J ",~ irt-i^-,'"'j-,-Ji -i-'': '!! ,-|-'-i-i--"-j-f"-J-r-it-;4-j-} *'")-»-^ rhH-i-i-i-'-f"''?
l;i^!^i|/:4^
. .
:l:i;l^iJji::jj!i':^ILI|r^!;i::^'!!i;;'^:j.jj:^^:ii:!la:^^ 'i£]si:'. l>?\-\\-Z\'',u;2£ ri^4;TJii^iLiIv^'iU;:^v.iJL:.ilLil'L:-:!.L
":'~:~[T;'::;3"J!r;":'""!'f'*!'!:'^'";;;}]ilP.if:T;111 "7 = irJl-H in*'7i;iI'^^"' n-^l'rrj'..;'i'.".'iT.\'l'''J^'T4r!;-;H'I':.TTi'"'.'":.?""";:"""'"
-hiyiiriii.rKlTini^-n;^
:::^:-::.:;K;;-;.:i.ii';li'j!::j:!::;;:!' j:;ii!ii:.!. :;::i:N;'i'lJiiJiJi:;.:;.:!'l;.!iii'iJ;jlJ.!j!.|.Lj:: ;.!.!!;.!-! iUlj.i^ili'li';!:: Lii;!;.:;:!;-^!!/:-!::;!;
89 10 11 '.12 13 14 15 16 17 18
-------
I
13.0
"
H
«
EH
1
I
oo
H
EH
:;S:{t|if3^
:;:..j.|. .$+[. .J-^TI.H..;.;: 3^.,: .Cfq
r-,-."!- -!-r-!-r-| <:-! t"."iT -i-rt -T a-t
1-r --r^' i-"i-rr-t-ri *!--! T-I + H-!
0.0
10.0
30.0 1*0.0
RIVER MILE
70.0
80.0
D"T r 11 o C
Q
-------
J3 '.?
-i-- r.'i
1,.'J!
«
§ /''
1'^
*'^.
\ -.. !
13.0
12.0 -
11'. 0 _
10.0 _
9.0 -
.8.0 _
6.0 _
§
0* £
v~4 r- i
5-0
J- . ^
± r-i
"S0 -k.O -
::.i o
«
B
I
- v-i ,:i\
CN '"
r\ :
CO
3.0 _
2.0--
E-- fH
^ i
1.0
0.0
!x^-fci:qHJfj:|:i±n:.H:djX|4j:Lid:pJ [::;^I]-:i:: i .i:^ji7'::::j:I;-~:-|-!:;:::;-j::-;-:.i.! ;.'.:'. j-;:.::;.u:,:;:':.!.:::
LCTJiTaxil^v!- jrizr.i:W-.f.i::i.tc.Ti:::n.jv.ix'j;:i:r:: v::r.:.:.n::; rr:J\r:: ":T!.;;::.:';.: ;--! i.:fl: r.i/ ::i-'-
_Mi.q nxj-i
.:i:;^:Ji"r4ii;Tpl,^:--:;te'fi^i:|"!^
::;. ! :n h.rn IT:; r. r:r: r::M. .::;rU.;-;::: |..rn IT.;.-r:;..!;;.::-.:7r T|T! irrr;
Sfl
it!-"
"
SH
xrtt
rJtf
-M-r-r -
ti:m
.i.-iiR.
H-n l-H-i-i-
ij'H-
i±E
:FfT-f
i-H-
ittt
t^iSitiB i£H' -:f^F"j';z:±.::-i:'r'':-::' LJ? '-' i-t;" SL:
r:J-:.i:.!.;;:-;;.:'j.'M'.i;rji ..;\;|c:r:i ~:;:.''^HiriiM.-."!^
' :.' .1 ..'.-> .... i _ - I .. . i\ I ' \ ' . 'f'
143+
flirun
mm
-i-ri |-|-'-i
.^^::|E-.ri>T-iy:^; ^
^/--;r-:-i-
SjTllin^TTjH^ r;:nT-"'r- !':-::rF!:;.:T' :E!; |:i"T: |'!r; i i'::'^i jj!"
^_J j ^ _,....,._.- u.
. --.I ;i- ...; I...!...i. ..:..:..... !!....! ...-
0.0
10.0
20.0
30.0
50.0
60.0
70.0
80.0
RIVER MILE'
FT/:/ »i?
-------
c:
Ci
c/o
CD
O QC
I <
U. C_
d
\r
i j
.-j
a
o
C
«r <; O
D- 0 S:
UJ
~v-.
. 16.0
15.0
14.0
.13.0
12.0
11.0
. 10.0
9-0
§ 8.0 -
§ 7.0
§6.0
O ' '
5.0
4.0
3.0
2.0
1.0
"O'.O
:i: !'!'!!:;:;;: I "!F:njH;ii::-:i!;i:!;:!;iy!!!'.^ih':i:!H!:i|^i:i
nj^rri'n'-Frn'iT^MTTTF"!":^
EijJIjij'iJ
;:;ii.;M;tfj;;.ijj:i;i!^
; T: jl: [rj ^!!;'-ij HJT p i flji ^i];; [j j JT! jjij ij J3 ^f, Ijjf jtjf f|f pfjjjt
:-ir:pt3iiifiI
initmwftUty.-
S fjnlEHiihlrflili!
i.pi^ i p- [$ fS^lf!-;j prlli^!; :
"rt"^"T~r rTr~r~"i~rr~TT^''T'' r<*^'
;;"..!:;:!;] jr.::] :.;.;..-f]T;:!Ti.rj4.-
J-rl t. rr« !- i I ti r-H t-t i i i :-i -
i:!^^ y±t' .r-TJ
*^ILTJ . rt'.-i i t« I + i
,-.p^"T:~r.;iTv|:-|-:
;|;v:i;:;-nn:;.:/;. t;::
; i-> r I -1 -i-n't IT* *(* *11
jBiiflMi kli
- r) rrrr-i -ri-t"---- r
«i4 M n i'K TiT;:
^;|''-rlI'i-'IM-P'!.lill
''rii WK ' iilvi i!r:.Tf i ii'i';": 1 Tf \;
-^T-^Ji-r4-rT>"*i-r ^Tf
WlS illlif
l
2
':5 6; V. -7 8 . 9:. 10 : if:.12 .. 13 14 . ! 15..-16'- 17 18
-------
o
zr C3
o ' I'
O C£
J «t
U. G-
I
1 y..
T ^i
>v O-
fJ
ti
c: ~~
ilJ
><
r) '-u
!-- i
el Q
O
I
j
00
t
o
'.A
X
on
r>
iliHi]|[|:{ij.'i;!Jl 'iliiiilTijHi;;i;^:i:Ji'
pSEfeii^;loi]fe;{|::N;^
in:!::!'::. ;:: :-,:;|;MI ;i::i::'|:i ;in^ :.!:Mr::.; ;;;.! r ;i
:.:i!:;';T|!:;i!:;;|j!;j;|.jij:!i i^fiUrili-fll^'l-itiiliii'H!! j'i 'i'l'f;
liiiilliJilijtifiHijIill^^^
liliiiijiljliiiiijljifjfij [|j!p!!i HiilHililliPllllfl^
7 8 9 10 -'ll' .12 . 13 14 15 16 17 18
FIGURE /;
------- |