Men are responsible for their own ejaculation. They have the following options to prevent sperm from entering drinking water.

1. Change your behavior

2. Address your sexual motivation

Motivating men to engage in sexual relationships solely for procreation — and not for pleasure, intimacy, or emotional connection — involves deeply personal, cultural, religious, or philosophical reasoning. This goal goes against mainstream sexual norms, so it requires a strong internal or external framework.

3. Take an SSRI daily

This medication provides increased control over ejaculation when taken daily (tip: keep it near your toothbrush). Discuss any side effects with your doctor and, if necessary, switch to a different type.
For reliable information, visit this page of the FDA.

Learn more:

. about the problem statement

. about the scientific evidence

. about this campaign