United States

Environmental Protection

Agency

Office of Water

Washington, D.C.

EPA 832-F-99-021

September 1999

Storm Water 

Management Fact Sheet

Materials Inventory

DESCRIPTION

A materials inventory system involves the

identification of all sources and quantities of

"significant" materials that may be exposed to direct

precipitation or storm water runoff at a particular

site. "Significant" materials are substances related

to industrial activities such as process chemicals,

raw materials, fuels, pesticides, and fertilizers.

When these substances are exposed to direct

precipitation or storm water runoff, they may be

carried to a receiving water body. Therefore,

identification of these materials helps to determine

sources of potential contamination and is the first

step in pollution control.

APPLICABILITY

A materials inventory system is appropriate at most

industrial facilities. Inventory of exposed materials

should be part of a baseline administrative program

and is directly related to both record keeping and

visual inspection Best Management Practices.

ADVANTAGES AND DISADVANTAGES

Since the program is intended to prevent pollution

before it occurs, it is not possible to quantify water

quality benefits to receiving waters of a materials

inventory program. However, it is anticipated that

an effective materials inventory program will

improve the quality of storm water discharges.

Limitations of a materials inventory system include:

• It is an on-going process that continually

needs updating.

• Qualified personnel are required to perform

the materials inventory from a storm water

perspective.

KEY PROGRAM COMPONENTS

Most facilities already have in place a materials

inventory system, but this system is not generally

followed from a storm water contamination

viewpoint. Adding storm water considerations into

an existing inventory should require only minimal

effort. When discussing a material inventory it is

very important to be aware of Material Safety Data

Sheets (MSDS). Currently the United States

Government has created a Hazard Communication

standard, which requires all firms manufacturing

and/or distributing chemicals within the United

States to prepare MSDSs for those chemicals and

distribute them to their customers. 

Keeping an up-to-date inventory of all materials

(hazardous and non-hazardous) on the site will help

to track how materials are stored and handled on

site, and identify which materials and activities pose

the greatest risk to the environment. The following

instructions explain the basic steps in completing a

materials inventory:

• Identify all chemical substances present in

the work place. Walk through the facility

and review the purchase orders for the

previous year. List all chemical substances

used in the work place and then obtain the

material safety data sheet (MSDS) for each.

• Label all containers to show the name and

type of substance, stock number, expiration

date, health hazards, suggestions for
MATERIAL INVENTORY

Worksheet Completed by:_____________________________

Title: _____________________________________________

Date: _____________________________________________

Instructions: List all materials used, stored, or produced on site. Assess and evaluate these materials for their

potential to contribute pollutants to storm water runoff. Also complete Worksheet 3A if the

material has been exposed during the last three years.

Quantity (units) Past Significant Spill or

Leak

Material Purpose /

Location Used Produced Stored

Quantity

exposed

during

last 3

years

Likelihood

of contact

with storm

water. If

yes,

describe

reason 

Yes No

Source: U. S. EPA, 1992.

FIGURE 1 SAMPLE MATERIAL INVENTORY

handling, and first aid information. This

information is found on the MSDS.

Unlabeled chemicals and chemicals with

deteriorated labels are often disposed of

improperly or unnecessarily.

• Clearly mark on the inventory those

hazardous materials that require specific

handling, storage, use, and disposal

considerations. 

An example Materials Inventory Worksheet is

provided in Figure 1. Based on your materials

inventory, describe the significant materials that

were exposed to storm water during the past three

years or are currently exposed.

Other BMPs should then be evaluated and

implemented to prevent exposure of these materials

to storm water or them before discharge. Figure 2

illustrates a sample worksheet for evaluating

exposed materials. 

IMPLEMENTATION

The key to a proper materials inventory system is

continual updating of records. Maintaining an

up-to-date materials inventory is an efficient way to

identify what materials are handled on-site and

whether they contribute to storm water

contamination problems. 

COSTS

Typically, the major cost of implementing a

materials inventory system is the time required to

adapt an existing program to emphasize storm water

quality. The incremental cost is usually small.

Costs of the program are often offset by cost

savings in other areas. Improved material tracking

and inventory practices, such as instituting a shelf

life program, can reduce the waste resulting from

the overstocking and disposal of outdated materials.

Careful tracking of all materials ordered may also

result in more efficient materials use.
DESCRIPTION OF EXPOSED SIGNIFICANT MATERIAL

Worksheet Completed by: ______

Title: _______________________

Date: _______________________

Instructions: Based on your material inventory, describe the significant materials that were exposed to storm

water during the past three years or are currently exposed. For the definition of “significant

materials” see Appendix B of the manual.

Description of

Exposed

Significant

Material

Period of

Exposure

Quantity

Exposed (units)

Location (as

indicated on

the site map)

Method of

Storage or

Disposal (e.g.,

pile, drum, tank)

Description of

Material

Management

Practice (e.g.,

pile covered,

drum sealed)

 Source: U. S. EPA, 1992.

FIGURE 2 EXPOSED MATERIAL WORKSHEET

REFERENCES

1. U.S. EPA, 1992. NPDES Best

Management Practices Guidance

Document.

2. U.S. EPA, 1992. Stormwater Management

for Industrial Activities: Developing

Pollution Prevention Plans and Best

Management Practices. EPA 832-R-92-

006.

ADDITIONAL INFORMATION

Center for Watershed Protection

Tom Schueler

8391 Main Street

Ellicott City, MD 21043

Northern Virginia Planning District Commission

David Bulova

7535 Little River Turnpike, Suite 100

Annandale, VA 22003

Oklahoma Department of Environmental Quality

Don Mooney

Water Quality Division, Storm Water Unit

P.O. Box 1677

Oklahoma City, OK 73101-1677

Southeastern Wis. Regional Planning Commission

Bob Biebel

916 N. East Avenue, P.O. Box 1607

Waukesha, WI 53187

United States Postal Service

Charles Vidich

6 Griffin Road North

Windsor, CT 06006-7030
For more information contact:

Municipal Technology Branch

U.S. EPA

Mail Code 4204

401 M St., S.W.

Washington, D.C., 20460

The mention of trade names or commercial products

does not constitute endorsement or recommendation

for the use by the U.S. Environmental Protection

Agency.