这样既省钱又减少污染用英语可以说为 "save money and reduce pollution" 或 "be cost-effective and environmentally friendly"。
其中 "save money" 意思是 "省钱"，"reduce pollution" 意思是 "减少污染"。
"cost-effective" 意思是 "经济实惠的"，"environmentally friendly" 意思是 "环保的"。
例句：
This new recycpng program is a win-win situation, it helps save money and reduce pollution.
(这个新的回收计划是双赢的，它既能帮助省钱，又能减少污染。)
We need to find ways to be cost-effective and environmentally friendly in our manufacturing process.
(我们需要找到在生产过程中经济实惠和环保的方法。)