As of the census of 2010, there were 8,785 people, 3,395 households, and 2,426 families residing in the city. The population density was. There were 3,587 housing units at an average density of. The racial makeup of the city was 91.0% White, 2.7% African American, 0.3% Native American, 2.5% Asian, 0.9% from other races, and 2.6% from two or more races. Hispanic or Latino of any race were 4.5% of the population. There were 3,395 households of which 38.1% had children under the age of 18 living with them, 56.3% were married couplesliving together, 11.1% had a female householder with no husband present, 4.1% had a male householder with no wife present, and 28.5% were non-families. 22.7% of all households were made up of individuals and 8.1% had someone living alone who was 65 years of age or older. The average household size was 2.57 and the average family size was 3.02. The median age in the city was 35.1 years. 27.4% of residents were under the age of 18; 7.6% were between the ages of 18 and 24; 29.3% were from 25 to 44; 24.4% were from 45 to 64; and 11.3% were 65 years of age or older. The gender makeup of the city was 46.8% male and 53.2% female.
2000 census
As of the census of 2000, there were 5,070 people, 1,900 households, and 1,451 families residing in the city. The population density was 647.1 people per square mile. There were 1,966 housing units at an average density of 250.9 per square mile. The racial makeup of the city was 95.03% White, 0.79% African American, 0.28% Native American, 1.74% Asian, 0.24% Pacific Islander, 1.12% from other races, and 0.81% from two or more races. Hispanic or Latino of any race were 2.43% of the population. There were 1,900 households out of which 35.5% had children under the age of 18 living with them, 65.4% were married couples living together, 8.3% had a female householder with no husband present, and 23.6% were non-families. 18.4% of all households were made up of individuals and 5.3% had someone living alone who was 65 years of age or older. The average household size was 2.63 and the average family size was 2.99. Age spread: 25.9% under the age of 18, 7.4% from 18 to 24, 31.7% from 25 to 44, 25.5% from 45 to 64, and 9.6% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 92.0 males. For every 100 females age 18 and over, there were 86.9 males. The median income for a household in the city was $60,694, and the median income for a family was $68,889. Males had a median income of $42,450 versus $29,697 for females. The per capita income for the city was $25,316. About 0.6% of families and 1.3% of the population were below the poverty line, including none of those under age 18 and 4.7% of those age 65 or over.
On November 20, 1983, an explosion of an explosives storage bunker just south of Pleasant Hill occurred. Reports were that two teenagers were hunting around the area. One of the teenagers may have shot a bullet from a hill which penetrated the bunker ceiling, which was deemed the probable cause of the explosion. The two teenagers were killed in the explosion, leaving only small pieces of shirts. The explosion was felt 45 miles away from the site. At least 25 homes within a one-mile radius of the explosion suffered damage, doors and windows were blown out, ceilings fell and houses were knocked off their foundations, police said. One house, 300 yards directly up the valley from the shack, suffered an inch-wide crack the entire width of its basement wall.
