Water: Septic
U.S Census Data on Small Community Housing and Wastewater Disposal and Plumbing Practices
Many people in small communities, those with fewer than 10,000 people, don't have access to public sewers. For these residents alternative wastewater systems are often used to solve their communities' public health problems and to help them comply with the Clean Water Act.
The 1990 Decennial Census of Population and Housing says 30 percent of all Americans live in small communities; 31.8 percent of the Nation's housing units are located in these communities (Figure 1). The Census contains information on the structural characteristics of these houses, plus wastewater disposal methods and types of plumbing facilities.

Did you know?
- 77 million people live in small communities.
- 11.7 million housing units in small communities are served by public sewers; 19.8 million use septic tanks or cesspools, and 917,373 use outhouses or privies.
- Pennsylvania has the most people living in small communities (4.4 million), and Texas has the greatest number of housing units in small communities (1,877,889).
- California has the highest number of housing units using outhouses or privies (67,865).
The sections that follow contain information on small community housing, wastewater disposal practices, and existing plumbing facilities. All data presented here are derived from the 1990 Census of Population and Housing. Table 1 provides a state-by-state summary of small community population, housing, sewage disposal and plumbing data.
Wastewater Disposal Methods
The Census Bureau categorizes U.S. wastewater disposal into three types: public sewer, septic tank or cesspool, and "other" means, such as privies and outhouses. In large communities (those with more than 10,000 people) almost 93 percent of the housing units are connected to a public sewer, 7 percent use septic tanks or cesspools, and 0.3 percent use other means (Figure 2). In contrast, about 61 percent of housing units in small communities use a septic tank or cesspool for wastewater disposal. Approximately 36 percent are hooked up to public sewers and nearly 3 percent use an alternative means of disposal. Other states with large numbers of small community housing units using outhouses/privies are: Kentucky (55,764), Pennsylvania (47,902), Missouri (46,223), and North Carolina (45,461).

Figure 3 shows that in eight out of ten Environmental Protection Agency (EPA) regions, septic tanks and cesspools are used by more than 50 percent of the small community housing units. When comparing the EPA regions, the proportion of housing units using septic tanks and cesspools varies. For example, in Region 1 about 71 percent of the homes use septic tanks or cesspools for sewage disposal as compared to 45 percent in Regions 7 and 8.

Plumbing Facilities
According to the Census, complete plumbing facilities means that a housing unit has hot and cold piped water, a flush toilet, and a bathtub or shower. All three facilities must be located inside the home but not necessarily in the same room.
Nationwide, 2.3 percent of housing units in small communities have incomplete plumbing facilities. This amounts to nearly three quarters of a million homes that have inadequate plumbing. Alaska has the highest percentage of incomplete plumbing facilities (24.6 percent), followed by Arizona (7.8 percent), New Mexico (7.4 percent), and Kentucky (5.0 percent). When evaluated by numbers rather than percentages, Texas has the highest number of incomplete plumbing facilities (50,214) in housing units, followed by Kentucky (41,707) and Virginia (40,162).
Small communities have a bigger problem with incomplete plumbing than large ones. Figure 4 illustrates the disparity between the percentages of small community housing units with incomplete plumbing facilities and large community housing units with incomplete plumbing facilities by EPA region. The percent of housing units in large communities with incomplete plumbing does not exceed 0.7 percent for any EPA region, whereas in small communities the percent is as high as 3.8 percent. As highlighted in Table 1, more than 70 percent of the Nation's housing units that lack complete plumbing facilities are in small communities.

EPA recognizes that small communities lag behind others in addressing their wastewater treatment and disposal needs. The Agency has, therefore, established several financial and technical assistance programs and centers to help these communities obtain appropriate sewage treatment and disposal systems. To learn more about these programs, visit the Office of Wastewater Management's website: http://www.epa.gov/OWM.
Small Community Census Data Tables:
| Table Name | On-line View | Text Download* |
Excel Spreadsheet Download |
| Table 1. State-by-State Summary of 1990 Census Bureau Data for Population, Housing, Sewerage, and Plumbing Data | |||
| Table 2. Regional Summary of 1990 Census Bureau Data for Population, Housing, Sewerage, and Plumbing Data | |||
| Table 3. National Summary of 1990 Census Bureau Data for Population, Housing, Sewerage, and Plumbing Data |
* Note: To download tab-delimited text, right-click on the selected icon, then save the file to the desired location.
