根据Law Insider,

Discharge or Disposal means the discharge, deposit, injection, dumping, spilling, leaking or placing of any hazardous materials into or on any land or water so that such materials or any constituent thereof may enter the environment or be discharged into any waters, including ground waters.

release、discharge「排放」废水

Japan has approved a plan to release more than one million tonnes of contaminated water from the destroyed Fukushima nuclear plant into the sea. (bbc.com 4/13)

（日本已经批准了一项计划，将从毁损的福岛核电厂中排放100万吨污水至海中。）

在此废水的「排放」可用release (v)。release可以当动词也可以当名词使用，而且在不同的情境有不同的意思。

●电影的上映或产品的上市和发布

（动词）The updated model of the product is scheduled to be released in September.

这个产品的新版预计于九月发布。

（名词）How do you usually find out about new movie releases?

你通常都是怎么获得新电影上映的消息？

●信息或新闻的公布和释出

The company has released further details regarding the merger.

这间公司刚公布有关并购的进一步消息。

In the news release, the company stated that the earthquake yesterday caused an extensive damage to their production facilities.

公司发布的新闻稿中，说明昨天的地震造成他们生产设备相当大的损害。

news release或是press release就是「新闻稿」。在很多新闻里，release更是常用在人的「释放」，如：

During the negotiation, the terrorist group promised to release the hostages they held for more than three years.

在谈判中，恐怖组织答应释放他们拘留超过三年的人质。

「释放」废水除了使用release外，也可以用discharge (v)「排放、排除」或是dump (v)、dispose (v)「丢弃」。

根据Cambridge Dictionary,

Dump is to put down or drop something in a careless way.

例句：

The factory was accused of dumping toxic chemical waste into the nearby river.

工厂被检举将有毒的化学废弃物倾倒于附近的河中。

Emit is a synonym for discharge in pour forth topic. In some cases you can use "Emit" instead a verb "Discharge", when it comes to topics like issue, give forth, get rid of, evacuate.

根据《气候变化框架公约》，所谓“排放”，是指“温室气体和/或其前体在一个特定地区和时期内向大气的释放”。（“Emissions” means the release of greenhouse gases and/or their precursors into the atmosphere over a specified area and period of time.）