DENR Administrative Order No.
35 Series of 1990
Year of
Enacted in 1990
Enactment
and
Implementatio
n
Purpose
To prevent, abate and control industrial pollution
Control Area
Nationwide
Overview
Effluent standards are limits in terms of concentration and/or volume
that any wastewater discharge coming from a point source i.e. industrial
plants and municipal sewerage systems shall meet. These consist of a
set of water quality parameters and their corresponding numerical
limits. Each set is prescribed for each of the water classes i.e. there is
one set of effluent standards for Class AA, another for Class A, etc.
Effluent standards are usually a certain factor say 10 over the Water
Quality Criteria.
Features
Effluent Standards for different water quality parameters are described
below:
Heavy Metals and Toxic Substances. - Industrial and other effluents when
discharged into bodies of water classified as Class A, B, C, D, SA, SB, SC and
SD in accordance with Section 68, as amended, of the 1978 NPCC Rules and
Regulations shall not contain toxic substances in levels greater than those
indicated in Table 1.
Table 1 - Effluent Standards: Toxic and Other Deleterious
Substance
(Maximum Limits for the Protection of Public Health) (a)
Protecte Protected Inland
d
Waters Waters
Waters
Parameter Unit
Marine Marine
Waters Waters
Categor Category Class C Class SC
yI
II
(Class
AA &
SA)
Class
SD
(Class
A,B &
SB)
OE NP OEI NPI OEI NPI OEI NPI OE NP
I
I
I I
Arsenic
mg/
(b) (b) 0.2
L
1.0
0.5 1.0 0.5
Cadmium
mg/
(b) (b) 0.05 0.02 0.1 0.05 0.2
L
0.1 0.5 0.2
0.1
0.5
Chromium mg/
(b) (b) 0.1 0.05 0.2
(hexavalent) L
0.2
0.1
0.5
0.2 1.0 0.5
Cyanide
mg/
(b) (b) 0.2
L
0.1
0.3
0.2
0.5
0.2
Lead
mg/
(b) (b) 0.2
L
0.1
0.5
0.3
1.0
0.5
Mercury
(Tot.)
mg/
0.00 0.00 0.00 0.00 0.00 0.00 0.0 0.0
(b) (b)
L
5
5
5
5
5
5
5 1
PCB
mg/
0.00 0.00 0.00 0.00 0.00 0.00
(b) (b)
L
3
3
3
3
3
3
Formaldehy mg/ (b) (b) 2.0
de
L
1.0
2.0
1.0
2.0
1.0
(a) Except as otherwise indicated, all limiting values in Table 1
(Section 4) are maximum and therefore shall not be exceeded.
(b) Discharge of sewage and/or trade effluents are prohibited or not
allowed.
Conventional and Other Pollutants Affecting Aesthetics and Oxygen
Demand. - Effluents from domestic sewage and industrial wastewater treatment
plants not covered under Section 6 of these Regulations, when discharged into
receiving waters classified as Class A, B, C, D, SA, SB, SC, and SD in
accordance with Section 68, as amended, of the 1978 NPCC Rules and
Regulations shall not contain the following pollutants in concentrations greater
than those indicated in Tables 2A and 2B.
Table 2A - EFFLUENT STANDARDS: Conventional and Other
Pollutants in Protected Waters Category I and II and in Inland
Waters Class C (a)
Protected Waters
Parameter
Unit
Inland
Waters
Category Category II
I
(Class AA (Class A, B
& SA)
& SB)
Class C
OEI NPI OEI NPI
Color
NPI
(b)
(b)
150
100
200c
150c
Temperature C rise
(max rise in
deg. Celsius in
RBW)
(b)
(b)
pH (range)
(b)
(b)
6.09.0
6.09.0
6.0-9.0 6.5-9.0
mg/L
(b)
(b)
100
60
150
100
Settleable
mg/L
Solids (1-hour)
(b)
(b)
0.3
0.3
0.5
0.5
5-Day 20 oC
BOD
mg/L
(b)
(b)
50
30
80
50
Total
Suspended
Solids
mg/L
(b)
(b)
70
50
90
70
Total
Dissolved
Solids
mg/L
(b)
(b)
1,200 1,000 -
COD
PCU
OEI
Surfactants
(MBAS)
mg/L
(b)
(b)
5.0
2.0
7.0
5.0
Oil/Grease
mg/L
(Petroleum
Ether Extract)
(b)
(b)
5.0
5.0
10.0
5.0
Phenolic
mg/L
Substances as
Phenols
(b)
(b)
0.1
0.05
0.5
0.1
MPN/100mL (b)
(b)
5,000 3,000 15,000 10,000
Total
Coliforms
(a) Except as otherwise indicated, all limiting values in Tables 2A and
2B are 90th percentile values. This is applicable only when the
discharger undertakes daily monitoring of its effluent quality,
otherwise, the numerical values in the tables represent maximum
values not to be exceeded once a year.
(b) Discharging of sewage and/or trade effluents is prohibited or not
allowed
Table 2B - EFFLUENTS STANDARDS: Conventional and Other
Pollutants in Inland Waters Class D, Coastal Waters Class SC and
SD and other Coastal Waters not yet Classified)
Parameter
Color
Temperature
(max. rise in
deg. Celsius
in RBW)
Inland Waters
Coastal
Waters
Class SD
& Other
Coastal
Waters
(Class D)
(Class SC)
Not
Classified
Unit
OEI
NPI
PCU
---
---
(c)
(c)
(c)
(c)
C rise
pH (range)
OEI NPI OEI NPI
5.0-9.0 6.0-9.0 6.09.0
6.0- 5.0- 5.09.0 9.0 9.0
COD
mg/L
250
200
250
200 300 200
5-Day 20 oC
BOD
mg/L
150 (d)
120
120
(d)
100 150 120
(d)
Total
mg/L
200
150
200
150
(g)
(f)
Suspended
Solids
Total
Dissolved
Solids
mg/L
2,000(h) 1,500(h)
Surfactants
(MBAS)
mg/L
15
10
Oil/Grease
(Petroleum
Ether
Extract)
mg/L
15
10
15
15
Phenolic
Substances
as Phenols
mg/L
1.0(i) 0.5(i) 5.0
1.0
Total
Coliforms
MPN/100mL
(j)
(j)
(c) Discharge shall not cause abnormal discoloration in the receiving
waters outside of the mixing zone
(d) For wastewaters with initial BOD concentration over 1,000 mg/L
but less than 3,000 mg/L, the limit may be exceeded up to a maximum
of 200 mg/L or a treatment reduction of ninety (90) percent, whichever
is more strict. Applicable to both old and new industries.
(f) Not more than 30 mg/L increase (dry season)
(g) Not more than 60 mg/L increase (dry season)
(h) If effluent is the sole source of supply for irrigation, the maximum
limits are 1,500 mg/L and 1,000 mg/L, respectively, for old industries
and new industries.
(i) Not present in concentration to affect fish flavor or taste or tainting.
(j) If effluent is used to irrigate vegetable and fruit crops which may be
eaten raw, Fecal Coliforms should be less than 500 MPN/100 mL.
NOTES for Table 2A and Table 2B:
1. In cases where the background level of Total Dissolved Solids
(TDS) in freshwater rivers, lakes, reservoirs and similar bodies
of water is higher than the Water Quality Criteria, the discharge
should not increase the level of TDS in the receiving body of
water by more than ten percent of the background level.
2. The COD limits in Tables 2A and 2B generally apply to
domestic wastewater treatment plant effluent. For industrial
discharges, the effluent standards for COD should be on a case
to case basis considering the COD BOD ratio after treatment.
In the interim period that this ratio is not yet established by
each discharger, the BOD requirements shall be enforced.
3. There are no effluent standards for chloride except for
industries using brine and discharging into inland waters, in
which case the chloride content should not exceed 500 mg/L.
4. The effluent standards apply to industrial manufacturing plants
and municipal treatment plants discharging more than thirty
(30) cubic meters per day.
Table 3A - Interim Effluent Standards for BOD Applicable to Old
or Existing Industries Producing Strong Industrial Wastes, (19901994)
Industry Classification
Based on BOD of Raw
Wastewaters Produced
Maximum Allowable Limits in mg/L,
according to
Time Period and Receiving Body of
Water
Effectivity date Dec. 31, 1991
Jan. 1, 1992-Dec.
31, 1994
Inland Waters
Coastal Waters
Inland Waters
Coastal Waters
(Class C (Class SC (Class C (Class SC
& D)
& SD)
& D)
& SD)
1. Industries producing
BOD within 3,000 to
10,000 mg/L
320
or
95%
removal
650
or
90%
removal
200
or
97%
removal
320
or
95%
removal
2. Industries producing
BOD within 10,000 to
30,000 mg/L
1,000
or
95%
removal
2,000
or
90%
removal
600
or
97%
removal
1,000
or
95%
removal
3. Industries producing
more than or 30,000 mg/L
1,500
or
95%
removal
3,000
or
90%
removal
900
or
97%
removal
1,500
or
95%
removal
Note: *
1. Use either the numerical limit or percentage removal whichever
is lower (or whichever is more strict).
2. Starting January 1, 1995, the applicable effluent requirements
for old or existing industries are indicated in Table 3B.
3. For parameters other than BOD, Table 2A and Table 2B both
under Section 5 shall apply.
Table 3B - Effluent Standards for New* Industries Producing
Strong Wastes upon Effectivity of these Regulations, and for All
Industries Producing Strong Wastes starting January 1, 1995.
Industry Classification
Based on BOD of Raw
Wastewater
Maximum Allowable Limits
in mg/L
Based on Receiving Body of
Water
Inland
Waters
Coastal
Waters
(Class C & D) (Class SC &
SD)
1. Industries producing within 3,000 to
10,000 mg BOD/L
130 or 98%
removal
200 or 97%
removal
2. Industries producing within 10,000
to 30,000 mg BOD/L
200 or 99%
removal
600 or 97%
removal
3. Industries producing more than
30,000 mg BOD/L
300 or 99%
removal
900 or 97%
removal
Note:*Including old or existing industries producing strong waste
whose wastewater treatment plants are still to be constructed.
1. Use either numerical limits or percentage removal whichever is
lower (or whichever is more strict).
2. For parameters other than BOD, Tables 2A and 2B shall apply.
Table 4 - Approved Methods of Analysis
PARAMETER
METHOD OF ANALYSIS
Arsenic
Silver Diethyldithiocarbamate Method
(Colorimetric)
BOD
Azide Modification (Dilution Technique)
Boron
Carmine Method (Colorimetric Method)
Cadmium
Atomic Absorption Spectrophotometry(Wet
ashing with concentration HNO3 + HCl)
Chlorinated
Hydrocarbons
Gas Chromatography (ECD)
Chromium
(Hexavalent)
Diphenyl Carbazine Colorimetric Method
Color
Visual Comparison Method Platinum Cobalt
Scale
Cyanide
Specific Ion Electrode Method
Dissolved Oxygen
Azide Modification (Winkler Method),
Membrane Electrode (DO meter)
Fecal Coliforms
Multiple-Tube Fermentation Technique or
Membrane Filter
Lead
Atomic Absorption Spectrophotometry
Nitrate As Nitrogen
Bruccine Method for Saline Waters, specific
Ion Electrode Meter for Fresh Water
Oil And Grease
Gravimetric Method (Petroleum Ether
Extraction)
Organo Phosphorus
Compounds
Gas Chromatography (FPD)
PCB
Gas Chromatography (ECD)
PH
Glass Electrode Method
Phenolic Substances
Chloroform Extraction Method
Phosphate As
Phosphorus
Stannous Chloride Method
Settleable Solids
Imhoff Cone Method
Surfactant (MBAS)
Methylene Blue Method (Colorimetric)
Temperature
Use of Mercury-Filled Thermometer
Total Coliforms
Multiple-Tube Fermentation Technique or
Membrane Filter
Total Mercury
Cold Vapor Technique, (Mercury Analyzer,
AAS)
Total Suspended
Solids
Gravimetric Method
Note: Other methods found in the Philippine Standard Methods for Air
and Water Analysis, the "Standard Methods for the Examination of
Water and Waste Waters", published jointly by American Public Health
Association, the American Waterworks Association and the Water
Pollution Control Federation of the U.S. or in accordance with such
other method of analyses as the DENR may prescribe.
Maximum Quantity to be Discharged. - For the protection of public health and
the aquatic resources of the country and in cases where the volume, strength
and nature of one or more pollutants, enumerated in, or not otherwise covered
in the preceeding Sections, are expected to cause a serious deterioration of a
receiving body of water or cause harm or injury to aquatic life and resources,
the Department Secretary shall promulgate guidelines for the use of the
concerned line agencies, providing for the maximum quantity of any pollutant
or contaminant that maybe allowed to be discharged into the said body of water
or watercourse, including the maximum rate at which the contaminant may be
so discharged.
This Section particularly applies, but is not limited to industrial effluents
covered under Section 6 of these regulations, specifying in kilograms per day
the BOD that may be discharged considering the classification and dry weather
flow of the receiving body of water.
Penalties. - Any person or group of persons found violating or failing to
comply with any Order or Decision of the Department and/or the Pollution
Adjudication Board or any provision of these Regulations, shall be liable under
Section 9 of the Pollution Control Law (PD No. 984) and/or Section 106 of the
1978 NPCC Rules and Regulations, as amended.
Separability Clause. - Any Section or provision of these regulations declared to
be unconstitutional or invalid by a competent court, the other sections or
provisions hereof shall remain to be in force.
Repealing Clause. - Any provision of the 1978 Rules and Regulations, as
amended, the Effluent Regulations of 1982, and other existing rules and
regulations of the Department which are inconsistent herewith are hereby
repealed.
