Directions: Determine whether each sentence is a run-on, is a comma splice, or is punctuated correctly.

Sentence	Type
Puerto Rico has many beautiful beaches and tropical rain forests, it also has many serious environmental issues.
This U.S. commonwealth has a large population there are approximately 1,000 people per square mile.
This ratio is higher than that in any of the 50 states in the United States the islands population density rivals those of Singapore, Hong Kong, and Taiwan.
Because of Puerto Ricos dense population, many environmental problems have arisen in this small island in the Caribbean.

Directions: Determine whether each sentence is a run-on, is a comma splice, or is punctuated correctly.

Sentence	Type
One of the biggest problems is water contamination from highways, factories, homes, agricultural fields, and septic systems.
Construction projects in Puerto Rico were loosely regulated, so the islands natural resources quickly became used up or polluted.
Rain picked up pollutants from these urban constructions, the pollutants became mixed into Puerto Ricos water supply.
This type of water contamination is called polluted runoff approximately 3,000 of the 5,384 miles of rivers and streams in Puerto Rico are now contaminated.

Directions: Determine whether each sentence is a run-on, is a comma splice, or is punctuated correctly.

Sentence	Type
In addition to runoff, some companies have dumped toxins into Puerto Ricos waters, in January 2009, Shell received a fine for doing this.
Shell violated the Clean Water Act this Act prohibits the unregulated contamination of public waters.
Puerto Rico now works with the Environmental Protection Agency (EPA) to regulate and prevent water pollution.
In 2000, the EPA approved a new program to stop runoff pollution in Puerto Rico, the program works toward preventing activities that damage water and coastal habitats.