Local Limits, Numerical

Local Limits, Numerical

The following sewer discharge limitations have been established for UC Davis. These limitations apply at the point of discharge to the sanitary sewer system (e.g., laboratory drains). Wastewater exceeding any of these limitations can not be discharged without specific approval from UC Davis Facilities Management - Utilities (the people responsible for operation of the Wastewater Treatment Plant). For constituents not listed below or other inquiries, please contact Michael Fan, Director of Utilities, mmfan@ucdavis.edu, (530) 752-7553. 

Printable version. (pdf)

CONSTITUENT

Local Limit *
ug/l
(for each discharger)
 

General

 

 Ammonia-Nitrogen

240,000

 BOD (5)

---

 Cyanide

20

 Total Suspended Solids

---

Electrical Conductivity 900 (umhos/cm)

Metals

 

 Aluminum

87

 Antimony

5.6

 Arsenic

8

 Barium

700

 Beryllium

4

 Cadmium

1.8

 Chromium VI (Hexavalent)

59

 Chromium (Total)

200

 Cobalt

1200

 Copper

No added copper

 Iron

3000

 Lead

21

 Molybdenum

8.5

 Nickel

52

 Selenium

3.5

 Silver

1.2

 Thallium

2.2

 Vanadium

540

 Zinc

120

Purgeable Halocarbons

 

 Bromodichloromethane

140

 Chlorobenzene

71

 Chloroform

420

 Dibromochloromethane

130

 1,2-Dichlorobenzene (o-DCB)

200

 1,3-Dichlorobenzene (m-DCB)

1,070

 1,4-Dichlorobenzene (p-DCB)

7

 Dichloromethane (MeC12)

100

 cis-1,3-Dichloropropene

0.7

Purgeable Aromatics

 

 Benzene

4

 Ethylbenzene

1,600

 Toluene

970

 Xylenes

2,000

Phenols

 

 2-Chlorophenol

2,800

 2,4-Dichlorophenol

130

 4-Nitrophenol

210

 Phenol

22,000

 2,4,6-Trichlorophenol

1,400

Chlorinated Pesticides & PCBs

 

 Aldrin

4

 apha-,beta-, and delta-BHC

0.11

 gamma-BHC (Lindane)

0.11

 Endosulfan I

0.056

 Endosulfan II

0.056

 Endosulfan Sulfate

0.079

 Methoxychlor

0.04

Chlorinated Hydrocarbons

 

 2-Chloronaphthalene

2,200

 Hexachlorobenzene

1

 Hexachloroethane

2.6

 1,2,4-Trichlorobenzene

100

Chlorinated Herbicides

 

 2,4-D

13

 Dicambia

300

 Dinoseb

10

 2,4,5-T

5,000,000

 2,4,5-TP (Silvex)

3.4

Semi-Volatile Organics

 

 Bis(2-chloroisopropyl) ether

2,000

 Diethyl phthalate

75,000

 Di-n-butylphthalate

1,900

 4-Methylphenol

310,000

 Naphthalene

1,000

Other

 

 Acetone (Dimethyl ketone)

1,097,000

 Formaldehyde ***

Non-hazardous (<2.9%)

Ethidium Bromide 10

* = Constituents which are specifically prohibited from discharge to the sewer in any amount are listed below. 

** = Local Limit must be determined on a case-by-case basis based on 90% of the difference between 
a) design capacity of the wastewater treatment plant for that month in lbs/day; and 
b) the average loading in the treatment plant influent for the previous 30-day period in lbs/day.

*** The former limit of 70 ppb was based on an extremely conserfactive fume toxicity calculation, which was eliminated in July 2012.

Specifically Prohibited Constituents

  • General:
    pH (<5 or >11); and Temperature (>104°F).
  • Metals:
    Mercury.
  • Other Organics:
    Carbon tetrachloride; 1,1-Dichloroethene (1,1-DCE); 2-Methyl-4,6-dinitrophenol; Benzidine; 3,3'-Dichlorobenzidine; alpha-Chlordane; DDD; DDE; DDT; Dieldrin; Endrin aldehyde; Heptachlor; Hexachlorobutadiene; Hexachlorocyclopentadiene; Bis(2-ethylhexyl)phthalate; and Tributyltin.
  • Total Petroleum Hydrocarbons:
    Diesel Fuel and Gasoline.
  • Other:
    Asbestos (at levels causing effluent to exceed drinking water standard or municipal sludge to exceed state hazardous substance criteria); and Excessive Total Oil and Grease.