Source Water Assessment Program
Inventory of Potential Contaminant Sources

4.1 Contaminants of Concern

The list of contaminants of concern must include raw water contaminants regulated under the Safe Drinking Water Act that have a maximum contaminant level (MCL), and cryptosporidium. MCL means the maximum permissible level of a contaminant in water which is delivered to any user of a public water supply system (NHHS, 1998). States may also include contaminants that are not federally regulated under the SDWA, but which the state has determined may present a threat to public health. In accordance with the Contamination Potential Rating (CPR) point system for ground water (Table 5.2), sources inside 1000 feet will be considered significant potential sources.
Below is the list of contaminants that PWSSs in Nebraska test for water quality. MCLs are listed strictly for informational purposes. New contaminants of concern may be added when new federal or state regulations are promulgated.

4.1.1 List of Contaminants of Concern
CONTAMINANTS TESTED FOR and REGULATED
These are drinking water contaminants that have a maximum contaminant level (MCL) and are regulated under the Nebraska Safe Drinking Water Act (NHHS,179, NAC2,1998).

CONTAMINANT
Coliform BacteriaThe MCL is based on the presence or absence of total coliforms in a sample (NHHS, 179, NAC2,002.02C1, 1998).
Inorganic Chemicals: MCL
Antimony 0.006 ppm
Arsenic 0.05 ppm
Asbestos 7M fibers/l
Barium 2.0 ppm
Beryllium 0.004 ppm
Cadmium 0.005 ppm
Chromium 0.1 ppm
Copper 1.3 ppm (Advisory Level)
Cyanide 0.2 ppm
Fluoride 4.0 ppm
Lead 0.015 ppm (Advisory Level)
Mercury 0.002 ppm
Nickel 0.1 ppm
Nitrate 10. ppm
Nitrite 1. ppm
Total nitrate and nitrite 10.0 ppm
Selenium 0.05 ppm
Sodium 500.0 ppm
Thallium 0.002 ppm
Synthetic Organic Chemicals:
Pesticides & Other Synthetic Organic Chemicals: MCL
Alachlor 2 ppb
Atrazine 3 ppb
Benzo(a)pyrene 0.2 ppb
Carbofuran 40 ppb
Chlordane 2 ppb
Dalapon 200 ppb
Di(2-ethylhexyl)adipate 400 ppb
Dibromochloropropane 0.2 ppb
Dinoseb 7 ppb
Di(2-ethylhexyl)phthalate 6 ppb
Diquat 20 ppb
2,4-D 70 ppb
Endothall 100 ppb
Endrin 2 ppb
Ethylene dibromide 0.05 ppb
Glyphosate 700 ppb
Heptachlor 0.4 ppb
Heptachlor epoxide 0.2 ppb
Hexachlorobenzene 1 ppb
Hexachlorocyclopentadiene 50 ppb
Lindane 0.2 ppb
Methoxychlor 40 ppb
Oxamyl (Vydate) 200 ppb
Pentachlorophenol 1 ppb
Picloram 500 ppb
Polychlorinated biphenyls 0.5 ppb
Simazine 4 ppb
Toxaphene 3 ppb
2,3,7,8-TCDD (Dioxin) 0.00003 ppb
2,4,5-TP (Silvex) 50 ppb
Volatile Organic Chemicals: MCL
Benzene 5 ppb
Carbon Tetrachloride 50 ppb
o-Dichlorobenzene 600 ppb
Para-Dichlorobenzene 75 ppb
1,2-Dichloroethane 5 ppb
1,1-Dichloroethylene 7 ppb
Cis-1,2-Dichloroethylene 70 ppb
Trans-1,2-Dichloroethylene 100 ppb
Dichloromethane 5 ppb
1,2-Dichloropropane 5 ppb
Ethylbenzene 700 ppb
Monochlorobenzene 100 ppb
1,2,4-Trichlorobenzene 70 ppb
1,1,1-Trichloroethane 200 ppb
1,1,2-Trichloroethane 5 ppb
Trichloroethylene 5 ppb
Vinyl Chloride 2 ppb
Styrene 100 ppb
Tetrachloroethylene 5 ppb
Toluene 1,000 ppb
Xylenes (total)10,000 ppb
Disinfection By-Products:
Total Trihalomethanes 100 ppb
Radionuclides:
Gross Alpha (minus 15 pCi/l
Uranium & Radium 226)
Radium 226 plus Radium 228 5 pCi/l
Abbreviations
full name of abbreviation
MCLMaximum Contaminant Level
M fibers/lMillion fibers per liter
ppbparts per billion, roughly equivalent to micrograms per liter
ppmparts per million, roughly equivalent to milligrams per liter
pCi/lpicoCuries per liter


CONTAMINANTS TESTED FOR/NOT REGULATED
States may also include contaminants that are not federally regulated under the SDWA, but the state has determined may present a threat to public health (NHHS, 1998). Nebraska Health and Human Services requires testing for the following non-regulated contaminants:

Inorganic Chemicals:

Sulfate

Volatile Organic Chemicals:

Chloroform
Bromodichloromethane
Chlorodibromomethane
Bromoform
Chlorobenzene
m-Dichlorobenzene
1,1-Dichloropropene
1,1-Dichloroethane
1,1,2,2-Tetrachloroethane
1,3-Dichloropropane
Chloromethane
Bromomethane
1,2,3-Trichloropropane
1,1,1,2-Tetrachloroethane
Chloroethane
2,2-Dichloropropane
o-Chlorotoluene
p-Chlorotoluene
Bromobenzene
1,3-Dichloropropene

Pesticides and Other Synthetic Organic Chemicals:

Aldrin
Butachlor
Carbaryl
Dicamba
Dieldrin
3-Hydroxycarbofuran
Methomyl
Metolachlor
Metribuzin
Propachlor


4.2 Ground Water Systems, Two Level Approach

4.2.1 Level One - Database Search

NDEQ will do a database search of potential contaminant sources within the WHPA (for all types of PWSSs), including databases from the following State Agencies:
A Draft Source Water Assessment including information from the agencies listed above will be shared with the PWS operator before completion. From the draft assessment, the PWSS will be able to make changes or additions if needed. The PWSS will be given a final Source Water Assessment, then the PWSS can move onto Level Two, when ready.

4.2.2 NDEQ’s Database

NDEQ has developed an Integrated Information System (IIS) which is a centralized, shared database containing descriptive and locational information for all facilities under the agency’s jurisdiction. A unique identification number is provided for each facility, and program staff correlate agency-wide information for a given facility. Additionally, IIS facility data is being developed for use with the Geographic Information System (GIS) by obtaining locational coordinates with address matching and from hand-held Global Positioning System (GPS) units. The following are programs or facility information that make up the IIS facility list:
4.2.3 Class V UIC Wells

The Underground Injection Control (UIC) program could contribute information on Class V injection wells in WHPAs and WDAs. This UIC program information is in the IIS. Proposed changes to federal UIC regulations could provide NDEQ with the regulatory influence to prohibit certain Class V wells.

4.2.4 Level Two - “On-the-Ground” Inventory for all Ground Water PWSSs

An “on-the-ground” inventory for ground water PWSSs may be done by the community or others at any time. This applies to Community and Non-Transient, Non-Community systems. Transient, Non-Community systems may also do an “on-the-ground” inventory. However, this type of system is only required to monitor nitrate and microbiological contaminants, therefore, they need only to inventory for those sources. As mentioned in section 4.2.1, the database search will be done for all types of PWSSs. The “on-the-ground” inventory will be completed as described in section 4.3.

4.3 Level Two - “On-the-Ground” Inventories

The next step in the inventory process is done by the community, using the level one database search as a starting point. An “on-the-ground” inventory may be done by the PWSS or community served by it. This action is voluntary and can be done at any time. NDEQ encourages PWSSs to use trained volunteers to do the inventory. This type of inventory applies to all PWSSs, ground water and surface water.

As will be explained in section 4.5, any time a level two “on-the-ground” inventory is completed the results must be sent in to NDEQ. This level two inventory is necessary before a more complete Contamination Potential Rating can be done.

4.3.1 The Contaminant Source Inventory Guidebook for Nebraska

To aid in the “on-the-ground” inventory effort, NDEQ has developed a Contaminant Source Inventory Guidebook (Inman, 1997), which can be a useful tool in completing an inventory. The Contaminant Source Inventory Guidebook includes categories of sources of contamination as well as an approach for identifying different types of land use or activities which may be potential sources of contamination. While this Guidebook was written for ground water systems, the same principles can be used for surface water systems as well.

Main topics in the Guidebook include a short description of Nebraska’s Wellhead Protection (WHP) program, what a contaminant source inventory is, some of the advantages of doing an inventory, how to recruit and train volunteers to do an inventory, materials and maps needed to do an inventory, how to do an inventory (including completed sample forms), recognizing the volunteers, and how to keep people in the community informed about the inventory process.

Extensive appendices include phone numbers and addresses for state and federal agencies/organizations, phone numbers and addresses for county assessors, local cooperative extension, and USDA offices, and phone numbers for regional agencies or organizations, such as Natural Resources Districts, Nebraska Department of Economic Development, Resource Conservation and Development Offices (RC&Ds), University of Nebraska, Midwest Assistance Program, and Groundwater Foundation.

The appendices also include blank and sample inventory forms, as noted above, and miscellaneous information, such as sample press releases. Tables of potential contaminant sources and materials that could be found at sites are also listed.

A copy of the Contaminant Source Inventory Guidebook is available free of charge to anyone, just by requesting it. Currently, it is also available on-line at: gwpc.site.net/sourcewater.Nebraska/NEguidebook01.htm. NDEQ anticipates having all the WHP Newsletters on-line soon. These will be found at:www.deq.state.ne.us under Programs, Water Quality Division, Ground Water Section, Wellhead Protection. WHP Newsletter 3 is about the Contaminant Source Inventory Guidebook and inventory process.

4.3.2 WHP Assistance through a CWA 319 Project

NDEQ is planning a FY99 Clean Water Act (CWA) Section 319 project to aid communities in WHP activities. NDEQ will contract with three Natural Resources Districts to hire a WHP Coordinator to assist local communities with “on-the-ground” Contaminant Source Inventories and Contaminant Source Management plans. These people will be in place for three years. NDEQ will provide support and training for these people. NDEQ hopes to expand this project to several other areas or regions after the first year. This project will enable one-on-one assistance to be given to PWSSs in the WHP program. Since the vast majority of Nebraska’s systems are ground water based, NDEQ is targeting these systems. Surface water source PWSS may participate in this project as well.

4.3.3 RC&D/Groundwater Foundation AmeriCorps Application

Several Resource Conservation and Development (RC&D) offices, in cooperation with the Groundwater Foundation, have applied for an AmeriCorps grant. This grant would place seven individuals in seven different areas of the state to do WHP and recycling/household hazardous waste activities. One of the main duties of these people would be to help communities do “on-the-ground” Contaminant Source Inventories and Contaminant Source Management plans. NDEQ will provide support and training for these people.

During the summer of 1998, several RC&Ds housed summer interns who helped communities do “on-the-ground” inventories. The lessons learned and successes of this short-term project encouraged the RC&Ds to apply for the AmeriCorps grant.

4.3.4 Train the Trainer Opportunities

Both the Midwest Assistance Program and the Nebraska Environmental Training Center (part of Central Community College at Hastings) have expressed interest in conducting “train-the-trainer” sessions. These sessions would train water operators and other community individuals on how to conduct “on-the-ground” inventories and how to recruit and train volunteers for doing inventories.

4.3.5 Groundwater Guardian

There are currently 13 Groundwater Guardian communities (a Groundwater Foundation program) in Nebraska. An activity that has been recognized as a good “Result Oriented Activity” (ROA) is an “on-the-ground” inventory. NDEQ supports and encourages Groundwater Guardian communities in WHP activities.

4.3.6 Nebraska Rural Water Association

The Nebraska Rural Water Association (NeRWA) works with communities on WHP activities. One of their efforts is to help towns (less than 10,000 population) with Contaminant Source Inventories. Once information from the NeRWA and their continuing efforts in the area of map drawing and inventories are coordinated, it will be a great benefit to the SWAP.

4.3.7 Sampling Waivers

NHHS has an existing waiver program that provides statewide waivers to all PWSSs, for contaminants that are not used in Nebraska. Beyond this type of waiver, it is possible for a PWSS to get an additional waiver, specific to a contaminant or water test for a group of contaminants. A Public Water Supply System that completes an “on the ground” contaminant source inventory may be able to use that information to help them apply for a water testing waiver from NHHS. An Inventory may show that the use and storage of a particular chemical has never occurred in the Wellhead Protection Area. NHHS may approve a reduced testing schedule for that particular chemical, thereby saving the community money.

4.4 Surface Water Systems, Two Level Approach

4.4.1 Level One - Database Search

The approach for Nebraska’s surface water systems is very similar to the ground water system approach described in Section 4.2 and 4.3. NDEQ will do a database search of potential contaminant sources within the established Assessment Area (24 hour Time-of-Travel zone), including the data from the following State Agencies:
All relevant information from these agencies will be used in a Source Water Assessment and given to the PWSS. Since some of the Assessment areas are relatively large, a priority will be made in the database search for direct discharges to surface water. In accordance with the Contamination Potential Rating point system for surface water (Table 5.5), sources inside the assessment area (24 hour TOT) will be considered significant potential sources. A Draft Source Water Assessment will be shared with the PWS operator before completion. From the draft assessment the PWSS will be able to make changes or additions if needed. The PWSS can then move onto Level Two, when ready. The area upstream of the 24 hour TOT zone will be delineated, but it will be up to the system to decide what is done in this area. NDEQ will not require any protection activities in this area. If known potential contamination sources lie outside the Assessment Area (24 hour TOT zone), they may be included in the first level inventory as well.

4.4.2 Level Two - “On-the-Ground” Inventories

Level two is exactly the same for surface water systems as it is for ground water systems. This is described above in section 4.3.

4.5 Responsibility

The Nebraska Department of Environmental Quality will assume the responsibility for completing the database search (Level One) for all PWSSs (ground water and surface water systems), and include the results in the Assessment for PWSSs to make any changes or additions.

Level Two, or “on-the-ground” inventories will be the responsibility of the PWSS and will remain voluntary. NDEQ has several projects planned to aid PWSSs with their
“on-the-ground” inventories. Once the “on-the-ground” inventory has been completed, PWSSs are required to send a copy of the results to NDEQ.


Nebraska Department of Environmental Quality
1200 "N" Street, Suite 400
P.O. Box 98922
Lincoln, Nebraska 68509
(402) 471-2186